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System "reboot" issue by using "sysrq" #2

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sghazagh opened this issue May 28, 2017 · 5 comments
Closed

System "reboot" issue by using "sysrq" #2

sghazagh opened this issue May 28, 2017 · 5 comments

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@sghazagh
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I have an "init" file for resizing the rootfs partition in first boot.
I need to use magic SysRq key "echo b > /proc/sysrq-trigger" to reboot the system after partition has resized.

The "sysrq" options in Kernel are enabled however, system cannot reboot.
It shut-downs the system immediately as expected but doesn't initiate the boot procedure.
Have to manually power-off and power-on the power source to make it boot again.

Can you please investigate and provide a solution?!
Thanks

@tido-
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tido- commented Jun 2, 2017

@sghazagh
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sghazagh commented Jun 2, 2017

Hi Tido,
Thanks for the reply.
But I downloaded the kernel after 5th/May so it should already have been fixed but it's not.
Can you please give me the commit or link showing the changes then I check and see if patched has applied?

I do appreciate your help.
(you always are helpful like what you did in Lemaker Forums :)

@tido-
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tido- commented Jun 3, 2017

Hi sghazagh,

I also thought I have seen that name before - same to you, thank you.
It was not compiled with the fixes until now, see here:
https://forum.armbian.com/index.php?/topic/3327-asus-tinkerboard/&do=findComment&comment=32887

@TinkerTeam
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Hi @sghazagh & @tido- ,

Thanks for your reply.
And it will be fixed in the next release.

@TinkerTeam
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Fix on 15a5310.

jamess-huang pushed a commit that referenced this issue Apr 13, 2018
commit 50a0cb565246f20d59cdb161778531e4b19d35ac upstream.

Starting with this commit 35eb8b81edd4 ("x86/efi: Build our own page
table structures") efi regions have a separate page directory called
"efi_pgd". In order to access any efi region we have to first shift %cr3
to this page table. In the bgrt code we are trying to copy bgrt_header
and image, but these regions fall under "EFI_BOOT_SERVICES_DATA"
and to access these regions we have to shift %cr3 to efi_pgd and not
doing so will cause page fault as shown below.

[    0.251599] Last level dTLB entries: 4KB 64, 2MB 0, 4MB 0, 1GB 4
[    0.259126] Freeing SMP alternatives memory: 32K (ffffffff8230e000 - ffffffff82316000)
[    0.271803] BUG: unable to handle kernel paging request at fffffffefce35002
[    0.279740] IP: [<ffffffff821bca49>] efi_bgrt_init+0x144/0x1fd
[    0.286383] PGD 300f067 PUD 0
[    0.289879] Oops: 0000 [#1] SMP
[    0.293566] Modules linked in:
[    0.297039] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.0-rc1-eywa-eywa-built-in-47041+ #2
[    0.306619] Hardware name: Intel Corporation Skylake Client platform/Skylake Y LPDDR3 RVP3, BIOS SKLSE2R1.R00.B104.B01.1511110114 11/11/2015
[    0.320925] task: ffffffff820134c0 ti: ffffffff82000000 task.ti: ffffffff82000000
[    0.329420] RIP: 0010:[<ffffffff821bca49>]  [<ffffffff821bca49>] efi_bgrt_init+0x144/0x1fd
[    0.338821] RSP: 0000:ffffffff82003f18  EFLAGS: 00010246
[    0.344852] RAX: fffffffefce35000 RBX: fffffffefce35000 RCX: fffffffefce2b000
[    0.352952] RDX: 000000008a82b000 RSI: ffffffff8235bb80 RDI: 000000008a835000
[    0.361050] RBP: ffffffff82003f30 R08: 000000008a865000 R09: ffffffffff202850
[    0.369149] R10: ffffffff811ad62f R11: 0000000000000000 R12: 0000000000000000
[    0.377248] R13: ffff88016dbaea40 R14: ffffffff822622c0 R15: ffffffff82003fb0
[    0.385348] FS:  0000000000000000(0000) GS:ffff88016d800000(0000) knlGS:0000000000000000
[    0.394533] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    0.401054] CR2: fffffffefce35002 CR3: 000000000300c000 CR4: 00000000003406f0
[    0.409153] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    0.417252] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    0.425350] Stack:
[    0.427638]  ffffffffffffffff ffffffff82256900 ffff88016dbaea40 ffffffff82003f40
[    0.436086]  ffffffff821bbce0 ffffffff82003f88 ffffffff8219c0c2 0000000000000000
[    0.444533]  ffffffff8219ba4a ffffffff822622c0 0000000000083000 00000000ffffffff
[    0.452978] Call Trace:
[    0.455763]  [<ffffffff821bbce0>] efi_late_init+0x9/0xb
[    0.461697]  [<ffffffff8219c0c2>] start_kernel+0x463/0x47f
[    0.467928]  [<ffffffff8219ba4a>] ? set_init_arg+0x55/0x55
[    0.474159]  [<ffffffff8219b120>] ? early_idt_handler_array+0x120/0x120
[    0.481669]  [<ffffffff8219b5ee>] x86_64_start_reservations+0x2a/0x2c
[    0.488982]  [<ffffffff8219b72d>] x86_64_start_kernel+0x13d/0x14c
[    0.495897] Code: 00 41 b4 01 48 8b 78 28 e8 09 36 01 00 48 85 c0 48 89 c3 75 13 48 c7 c7 f8 ac d3 81 31 c0 e8 d7 3b fb fe e9 b5 00 00 00 45 84 e4 <44> 8b 6b 02 74 0d be 06 00 00 00 48 89 df e8 ae 34 0$
[    0.518151] RIP  [<ffffffff821bca49>] efi_bgrt_init+0x144/0x1fd
[    0.524888]  RSP <ffffffff82003f18>
[    0.528851] CR2: fffffffefce35002
[    0.532615] ---[ end trace 7b06521e6ebf2aea ]---
[    0.537852] Kernel panic - not syncing: Attempted to kill the idle task!

As said above one way to fix this bug is to shift %cr3 to efi_pgd but we
are not doing that way because it leaks inner details of how we switch
to EFI page tables into a new call site and it also adds duplicate code.
Instead, we remove the call to efi_lookup_mapped_addr() and always
perform early_mem*() instead of early_io*() because we want to remap RAM
regions and not I/O regions. We also delete efi_lookup_mapped_addr()
because we are no longer using it.

Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Reported-by: Wendy Wang <wendy.wang@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: "Ghannam, Yazen" <Yazen.Ghannam@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Apr 13, 2018
commit e2c90dd7e11e3025b46719a79fb4bb1e7a5cef9f upstream.

Môshe reported the following warning triggered on his machine since
commit 50a0cb565246 ("x86/efi-bgrt: Fix kernel panic when mapping BGRT
data"),

  [    0.026936] ------------[ cut here ]------------
  [    0.026941] WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:137 __early_ioremap+0x102/0x1bb()
  [    0.026941] Modules linked in:
  [    0.026944] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.0-rc1 #2
  [    0.026945] Hardware name: Dell Inc. XPS 13 9343/09K8G1, BIOS A05 07/14/2015
  [    0.026946]  0000000000000000 900f03d5a116524d ffffffff81c03e60 ffffffff813a3fff
  [    0.026948]  0000000000000000 ffffffff81c03e98 ffffffff810a0852 00000000d7b76000
  [    0.026949]  0000000000000000 0000000000000001 0000000000000001 000000000000017c
  [    0.026951] Call Trace:
  [    0.026955]  [<ffffffff813a3fff>] dump_stack+0x44/0x55
  [    0.026958]  [<ffffffff810a0852>] warn_slowpath_common+0x82/0xc0
  [    0.026959]  [<ffffffff810a099a>] warn_slowpath_null+0x1a/0x20
  [    0.026961]  [<ffffffff81d8c395>] __early_ioremap+0x102/0x1bb
  [    0.026962]  [<ffffffff81d8c602>] early_memremap+0x13/0x15
  [    0.026964]  [<ffffffff81d78361>] efi_bgrt_init+0x162/0x1ad
  [    0.026966]  [<ffffffff81d778ec>] efi_late_init+0x9/0xb
  [    0.026968]  [<ffffffff81d58ff5>] start_kernel+0x46f/0x49f
  [    0.026970]  [<ffffffff81d58120>] ? early_idt_handler_array+0x120/0x120
  [    0.026972]  [<ffffffff81d58339>] x86_64_start_reservations+0x2a/0x2c
  [    0.026974]  [<ffffffff81d58485>] x86_64_start_kernel+0x14a/0x16d
  [    0.026977] ---[ end trace f9b3812eb8e24c58 ]---
  [    0.026978] efi_bgrt: Ignoring BGRT: failed to map image memory

early_memremap() has an upper limit on the size of mapping it can
handle which is ~200KB. Clearly the BGRT image on Môshe's machine is
much larger than that.

There's actually no reason to restrict ourselves to using the early_*
version of memremap() - the ACPI BGRT driver is invoked late enough in
boot that we can use the standard version, with the benefit that the
late version allows mappings of arbitrary size.

Reported-by: Môshe van der Sterre <me@moshe.nl>
Tested-by: Môshe van der Sterre <me@moshe.nl>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1450707172-12561-1-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Ghannam, Yazen" <Yazen.Ghannam@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Apr 13, 2018
[ Upstream commit f3069c6d33f6ae63a1668737bc78aaaa51bff7ca ]

This is a fix for syzkaller719569, where memory registration was
attempted without any underlying transport being loaded.

Analysis of the case reveals that it is the setsockopt() RDS_GET_MR
(2) and RDS_GET_MR_FOR_DEST (7) that are vulnerable.

Here is an example stack trace when the bug is hit:

BUG: unable to handle kernel NULL pointer dereference at 00000000000000c0
IP: __rds_rdma_map+0x36/0x440 [rds]
PGD 2f93d03067 P4D 2f93d03067 PUD 2f93d02067 PMD 0
Oops: 0000 [#1] SMP
Modules linked in: bridge stp llc tun rpcsec_gss_krb5 nfsv4
dns_resolver nfs fscache rds binfmt_misc sb_edac intel_powerclamp
coretemp kvm_intel kvm irqbypass crct10dif_pclmul c rc32_pclmul
ghash_clmulni_intel pcbc aesni_intel crypto_simd glue_helper cryptd
iTCO_wdt mei_me sg iTCO_vendor_support ipmi_si mei ipmi_devintf nfsd
shpchp pcspkr i2c_i801 ioatd ma ipmi_msghandler wmi lpc_ich mfd_core
auth_rpcgss nfs_acl lockd grace sunrpc ip_tables ext4 mbcache jbd2
mgag200 i2c_algo_bit drm_kms_helper ixgbe syscopyarea ahci sysfillrect
sysimgblt libahci mdio fb_sys_fops ttm ptp libata sd_mod mlx4_core drm
crc32c_intel pps_core megaraid_sas i2c_core dca dm_mirror
dm_region_hash dm_log dm_mod
CPU: 48 PID: 45787 Comm: repro_set2 Not tainted 4.14.2-3.el7uek.x86_64 #2
Hardware name: Oracle Corporation ORACLE SERVER X5-2L/ASM,MOBO TRAY,2U, BIOS 31110000 03/03/2017
task: ffff882f9190db00 task.stack: ffffc9002b994000
RIP: 0010:__rds_rdma_map+0x36/0x440 [rds]
RSP: 0018:ffffc9002b997df0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff882fa2182580 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffc9002b997e40 RDI: ffff882fa2182580
RBP: ffffc9002b997e30 R08: 0000000000000000 R09: 0000000000000002
R10: ffff885fb29e3838 R11: 0000000000000000 R12: ffff882fa2182580
R13: ffff882fa2182580 R14: 0000000000000002 R15: 0000000020000ffc
FS:  00007fbffa20b700(0000) GS:ffff882fbfb80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000c0 CR3: 0000002f98a66006 CR4: 00000000001606e0
Call Trace:
 rds_get_mr+0x56/0x80 [rds]
 rds_setsockopt+0x172/0x340 [rds]
 ? __fget_light+0x25/0x60
 ? __fdget+0x13/0x20
 SyS_setsockopt+0x80/0xe0
 do_syscall_64+0x67/0x1b0
 entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x7fbff9b117f9
RSP: 002b:00007fbffa20aed8 EFLAGS: 00000293 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00000000000c84a4 RCX: 00007fbff9b117f9
RDX: 0000000000000002 RSI: 0000400000000114 RDI: 000000000000109b
RBP: 00007fbffa20af10 R08: 0000000000000020 R09: 00007fbff9dd7860
R10: 0000000020000ffc R11: 0000000000000293 R12: 0000000000000000
R13: 00007fbffa20b9c0 R14: 00007fbffa20b700 R15: 0000000000000021

Code: 41 56 41 55 49 89 fd 41 54 53 48 83 ec 18 8b 87 f0 02 00 00 48
89 55 d0 48 89 4d c8 85 c0 0f 84 2d 03 00 00 48 8b 87 00 03 00 00 <48>
83 b8 c0 00 00 00 00 0f 84 25 03 00 0 0 48 8b 06 48 8b 56 08

The fix is to check the existence of an underlying transport in
__rds_rdma_map().

Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Apr 13, 2018
[ Upstream commit e1699d2d7bf6e6cce3e1baff19f9dd4595a58664 ]

This is a story about 4 distinct (and very old) btrfs bugs.

Commit c8b9781 ("Btrfs: Add zlib compression support") added
three data corruption bugs for inline extents (bugs #1-3).

Commit 93c82d5 ("Btrfs: zero page past end of inline file items")
fixed bug #1:  uncompressed inline extents followed by a hole and more
extents could get non-zero data in the hole as they were read.  The fix
was to add a memset in btrfs_get_extent to zero out the hole.

Commit 166ae5a ("btrfs: fix inline compressed read err corruption")
fixed bug #2:  compressed inline extents which contained non-zero bytes
might be replaced with zero bytes in some cases.  This patch removed an
unhelpful memset from uncompress_inline, but the case where memset is
required was missed.

There is also a memset in the decompression code, but this only covers
decompressed data that is shorter than the ram_bytes from the extent
ref record.  This memset doesn't cover the region between the end of the
decompressed data and the end of the page.  It has also moved around a
few times over the years, so there's no single patch to refer to.

This patch fixes bug #3:  compressed inline extents followed by a hole
and more extents could get non-zero data in the hole as they were read
(i.e. bug #3 is the same as bug #1, but s/uncompressed/compressed/).
The fix is the same:  zero out the hole in the compressed case too,
by putting a memset back in uncompress_inline, but this time with
correct parameters.

The last and oldest bug, bug #0, is the cause of the offending inline
extent/hole/extent pattern.  Bug #0 is a subtle and mostly-harmless quirk
of behavior somewhere in the btrfs write code.  In a few special cases,
an inline extent and hole are allowed to persist where they normally
would be combined with later extents in the file.

A fast reproducer for bug #0 is presented below.  A few offending extents
are also created in the wild during large rsync transfers with the -S
flag.  A Linux kernel build (git checkout; make allyesconfig; make -j8)
will produce a handful of offending files as well.  Once an offending
file is created, it can present different content to userspace each
time it is read.

Bug #0 is at least 4 and possibly 8 years old.  I verified every vX.Y
kernel back to v3.5 has this behavior.  There are fossil records of this
bug's effects in commits all the way back to v2.6.32.  I have no reason
to believe bug #0 wasn't present at the beginning of btrfs compression
support in v2.6.29, but I can't easily test kernels that old to be sure.

It is not clear whether bug #0 is worth fixing.  A fix would likely
require injecting extra reads into currently write-only paths, and most
of the exceptional cases caused by bug #0 are already handled now.

Whether we like them or not, bug #0's inline extents followed by holes
are part of the btrfs de-facto disk format now, and we need to be able
to read them without data corruption or an infoleak.  So enough about
bug #0, let's get back to bug #3 (this patch).

An example of on-disk structure leading to data corruption found in
the wild:

        item 61 key (606890 INODE_ITEM 0) itemoff 9662 itemsize 160
                inode generation 50 transid 50 size 47424 nbytes 49141
                block group 0 mode 100644 links 1 uid 0 gid 0
                rdev 0 flags 0x0(none)
        item 62 key (606890 INODE_REF 603050) itemoff 9642 itemsize 20
                inode ref index 3 namelen 10 name: DB_File.so
        item 63 key (606890 EXTENT_DATA 0) itemoff 8280 itemsize 1362
                inline extent data size 1341 ram 4085 compress(zlib)
        item 64 key (606890 EXTENT_DATA 4096) itemoff 8227 itemsize 53
                extent data disk byte 5367308288 nr 20480
                extent data offset 0 nr 45056 ram 45056
                extent compression(zlib)

Different data appears in userspace during each read of the 11 bytes
between 4085 and 4096.  The extent in item 63 is not long enough to
fill the first page of the file, so a memset is required to fill the
space between item 63 (ending at 4085) and item 64 (beginning at 4096)
with zero.

Here is a reproducer from Liu Bo, which demonstrates another method
of creating the same inline extent and hole pattern:

Using 'page_poison=on' kernel command line (or enable
CONFIG_PAGE_POISONING) run the following:

	# touch foo
	# chattr +c foo
	# xfs_io -f -c "pwrite -W 0 1000" foo
	# xfs_io -f -c "falloc 4 8188" foo
	# od -x foo
	# echo 3 >/proc/sys/vm/drop_caches
	# od -x foo

This produce the following on my box:

Correct output:  file contains 1000 data bytes followed
by zeros:

	0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd
	*
	0001740 cdcd cdcd cdcd cdcd 0000 0000 0000 0000
	0001760 0000 0000 0000 0000 0000 0000 0000 0000
	*
	0020000

Actual output:  the data after the first 1000 bytes
will be different each run:

	0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd
	*
	0001740 cdcd cdcd cdcd cdcd 6c63 7400 635f 006d
	0001760 5f74 6f43 7400 435f 0053 5f74 7363 7400
	0002000 435f 0056 5f74 6164 7400 645f 0062 5f74
	(...)

Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Chris Mason <clm@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Apr 13, 2018
[ Upstream commit ec4fbd64751de18729eaa816ec69e4b504b5a7a2 ]

Dmitry reported a lockdep splat [1] (false positive) that we can fix
by releasing the spinlock before calling icmp_send() from ip_expire()

This is a false positive because sending an ICMP message can not
possibly re-enter the IP frag engine.

[1]
[ INFO: possible circular locking dependency detected ]
4.10.0+ #29 Not tainted
-------------------------------------------------------
modprobe/12392 is trying to acquire lock:
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] spin_lock
include/linux/spinlock.h:299 [inline]
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>] __netif_tx_lock
include/linux/netdevice.h:3486 [inline]
 (_xmit_ETHER#2){+.-...}, at: [<ffffffff837a8182>]
sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180

but task is already holding lock:
 (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock
include/linux/spinlock.h:299 [inline]
 (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>]
ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&(&q->lock)->rlock){+.-...}:
       validate_chain kernel/locking/lockdep.c:2267 [inline]
       __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
       lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
       spin_lock include/linux/spinlock.h:299 [inline]
       ip_defrag+0x3a2/0x4130 net/ipv4/ip_fragment.c:669
       ip_check_defrag+0x4e3/0x8b0 net/ipv4/ip_fragment.c:713
       packet_rcv_fanout+0x282/0x800 net/packet/af_packet.c:1459
       deliver_skb net/core/dev.c:1834 [inline]
       dev_queue_xmit_nit+0x294/0xa90 net/core/dev.c:1890
       xmit_one net/core/dev.c:2903 [inline]
       dev_hard_start_xmit+0x16b/0xab0 net/core/dev.c:2923
       sch_direct_xmit+0x31f/0x6d0 net/sched/sch_generic.c:182
       __dev_xmit_skb net/core/dev.c:3092 [inline]
       __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
       dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
       neigh_resolve_output+0x6b9/0xb10 net/core/neighbour.c:1308
       neigh_output include/net/neighbour.h:478 [inline]
       ip_finish_output2+0x8b8/0x15a0 net/ipv4/ip_output.c:228
       ip_do_fragment+0x1d93/0x2720 net/ipv4/ip_output.c:672
       ip_fragment.constprop.54+0x145/0x200 net/ipv4/ip_output.c:545
       ip_finish_output+0x82d/0xe10 net/ipv4/ip_output.c:314
       NF_HOOK_COND include/linux/netfilter.h:246 [inline]
       ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
       dst_output include/net/dst.h:486 [inline]
       ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
       ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
       ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
       raw_sendmsg+0x26de/0x3a00 net/ipv4/raw.c:655
       inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:761
       sock_sendmsg_nosec net/socket.c:633 [inline]
       sock_sendmsg+0xca/0x110 net/socket.c:643
       ___sys_sendmsg+0x4a3/0x9f0 net/socket.c:1985
       __sys_sendmmsg+0x25c/0x750 net/socket.c:2075
       SYSC_sendmmsg net/socket.c:2106 [inline]
       SyS_sendmmsg+0x35/0x60 net/socket.c:2101
       do_syscall_64+0x2e8/0x930 arch/x86/entry/common.c:281
       return_from_SYSCALL_64+0x0/0x7a

-> #0 (_xmit_ETHER#2){+.-...}:
       check_prev_add kernel/locking/lockdep.c:1830 [inline]
       check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940
       validate_chain kernel/locking/lockdep.c:2267 [inline]
       __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
       lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
       spin_lock include/linux/spinlock.h:299 [inline]
       __netif_tx_lock include/linux/netdevice.h:3486 [inline]
       sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180
       __dev_xmit_skb net/core/dev.c:3092 [inline]
       __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
       dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
       neigh_hh_output include/net/neighbour.h:468 [inline]
       neigh_output include/net/neighbour.h:476 [inline]
       ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228
       ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316
       NF_HOOK_COND include/linux/netfilter.h:246 [inline]
       ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
       dst_output include/net/dst.h:486 [inline]
       ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
       ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
       ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
       icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394
       icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754
       ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239
       call_timer_fn+0x241/0x820 kernel/time/timer.c:1268
       expire_timers kernel/time/timer.c:1307 [inline]
       __run_timers+0x960/0xcf0 kernel/time/timer.c:1601
       run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614
       __do_softirq+0x31f/0xbe7 kernel/softirq.c:284
       invoke_softirq kernel/softirq.c:364 [inline]
       irq_exit+0x1cc/0x200 kernel/softirq.c:405
       exiting_irq arch/x86/include/asm/apic.h:657 [inline]
       smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962
       apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707
       __read_once_size include/linux/compiler.h:254 [inline]
       atomic_read arch/x86/include/asm/atomic.h:26 [inline]
       rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline]
       __rcu_is_watching kernel/rcu/tree.c:1133 [inline]
       rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147
       rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293
       radix_tree_deref_slot include/linux/radix-tree.h:238 [inline]
       filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335
       do_fault_around mm/memory.c:3231 [inline]
       do_read_fault mm/memory.c:3265 [inline]
       do_fault+0xbd5/0x2080 mm/memory.c:3370
       handle_pte_fault mm/memory.c:3600 [inline]
       __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714
       handle_mm_fault+0x1e2/0x480 mm/memory.c:3751
       __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397
       do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460
       page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&(&q->lock)->rlock);
                               lock(_xmit_ETHER#2);
                               lock(&(&q->lock)->rlock);
  lock(_xmit_ETHER#2);

 *** DEADLOCK ***

10 locks held by modprobe/12392:
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff81329758>]
__do_page_fault+0x2b8/0xb60 arch/x86/mm/fault.c:1336
 #1:  (rcu_read_lock){......}, at: [<ffffffff8188cab6>]
filemap_map_pages+0x1e6/0x1570 mm/filemap.c:2324
 #2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
spin_lock include/linux/spinlock.h:299 [inline]
 #2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
pte_alloc_one_map mm/memory.c:2944 [inline]
 #2:  (&(ptlock_ptr(page))->rlock#2){+.+...}, at: [<ffffffff81984a78>]
alloc_set_pte+0x13b8/0x1b90 mm/memory.c:3072
 #3:  (((&q->timer))){+.-...}, at: [<ffffffff81627e72>]
lockdep_copy_map include/linux/lockdep.h:175 [inline]
 #3:  (((&q->timer))){+.-...}, at: [<ffffffff81627e72>]
call_timer_fn+0x1c2/0x820 kernel/time/timer.c:1258
 #4:  (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>] spin_lock
include/linux/spinlock.h:299 [inline]
 #4:  (&(&q->lock)->rlock){+.-...}, at: [<ffffffff8389a4d1>]
ip_expire+0x51/0x6c0 net/ipv4/ip_fragment.c:201
 #5:  (rcu_read_lock){......}, at: [<ffffffff8389a633>]
ip_expire+0x1b3/0x6c0 net/ipv4/ip_fragment.c:216
 #6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] spin_trylock
include/linux/spinlock.h:309 [inline]
 #6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>] icmp_xmit_lock
net/ipv4/icmp.c:219 [inline]
 #6:  (slock-AF_INET){+.-...}, at: [<ffffffff839b3313>]
icmp_send+0x803/0x1c80 net/ipv4/icmp.c:681
 #7:  (rcu_read_lock_bh){......}, at: [<ffffffff838ab9a1>]
ip_finish_output2+0x2c1/0x15a0 net/ipv4/ip_output.c:198
 #8:  (rcu_read_lock_bh){......}, at: [<ffffffff836d1dee>]
__dev_queue_xmit+0x23e/0x1e60 net/core/dev.c:3324
 #9:  (dev->qdisc_running_key ?: &qdisc_running_key){+.....}, at:
[<ffffffff836d3a27>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3423

stack backtrace:
CPU: 0 PID: 12392 Comm: modprobe Not tainted 4.10.0+ #29
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x2ee/0x3ef lib/dump_stack.c:52
 print_circular_bug+0x307/0x3b0 kernel/locking/lockdep.c:1204
 check_prev_add kernel/locking/lockdep.c:1830 [inline]
 check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940
 validate_chain kernel/locking/lockdep.c:2267 [inline]
 __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340
 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x33/0x50 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:299 [inline]
 __netif_tx_lock include/linux/netdevice.h:3486 [inline]
 sch_direct_xmit+0x282/0x6d0 net/sched/sch_generic.c:180
 __dev_xmit_skb net/core/dev.c:3092 [inline]
 __dev_queue_xmit+0x13e5/0x1e60 net/core/dev.c:3358
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3423
 neigh_hh_output include/net/neighbour.h:468 [inline]
 neigh_output include/net/neighbour.h:476 [inline]
 ip_finish_output2+0xf6c/0x15a0 net/ipv4/ip_output.c:228
 ip_finish_output+0xa29/0xe10 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:246 [inline]
 ip_output+0x1f0/0x7a0 net/ipv4/ip_output.c:404
 dst_output include/net/dst.h:486 [inline]
 ip_local_out+0x95/0x170 net/ipv4/ip_output.c:124
 ip_send_skb+0x3c/0xc0 net/ipv4/ip_output.c:1492
 ip_push_pending_frames+0x64/0x80 net/ipv4/ip_output.c:1512
 icmp_push_reply+0x372/0x4d0 net/ipv4/icmp.c:394
 icmp_send+0x156c/0x1c80 net/ipv4/icmp.c:754
 ip_expire+0x40e/0x6c0 net/ipv4/ip_fragment.c:239
 call_timer_fn+0x241/0x820 kernel/time/timer.c:1268
 expire_timers kernel/time/timer.c:1307 [inline]
 __run_timers+0x960/0xcf0 kernel/time/timer.c:1601
 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614
 __do_softirq+0x31f/0xbe7 kernel/softirq.c:284
 invoke_softirq kernel/softirq.c:364 [inline]
 irq_exit+0x1cc/0x200 kernel/softirq.c:405
 exiting_irq arch/x86/include/asm/apic.h:657 [inline]
 smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962
 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:707
RIP: 0010:__read_once_size include/linux/compiler.h:254 [inline]
RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:26 [inline]
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:350 [inline]
RIP: 0010:__rcu_is_watching kernel/rcu/tree.c:1133 [inline]
RIP: 0010:rcu_is_watching+0x83/0x110 kernel/rcu/tree.c:1147
RSP: 0000:ffff8801c391f120 EFLAGS: 00000a03 ORIG_RAX: ffffffffffffff10
RAX: dffffc0000000000 RBX: ffff8801c391f148 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 000055edd4374000 RDI: ffff8801dbe1ae0c
RBP: ffff8801c391f1a0 R08: 0000000000000002 R09: 0000000000000000
R10: dffffc0000000000 R11: 0000000000000002 R12: 1ffff10038723e25
R13: ffff8801dbe1ae00 R14: ffff8801c391f680 R15: dffffc0000000000
 </IRQ>
 rcu_read_lock_held+0x87/0xc0 kernel/rcu/update.c:293
 radix_tree_deref_slot include/linux/radix-tree.h:238 [inline]
 filemap_map_pages+0x6d4/0x1570 mm/filemap.c:2335
 do_fault_around mm/memory.c:3231 [inline]
 do_read_fault mm/memory.c:3265 [inline]
 do_fault+0xbd5/0x2080 mm/memory.c:3370
 handle_pte_fault mm/memory.c:3600 [inline]
 __handle_mm_fault+0x1062/0x2cb0 mm/memory.c:3714
 handle_mm_fault+0x1e2/0x480 mm/memory.c:3751
 __do_page_fault+0x4f6/0xb60 arch/x86/mm/fault.c:1397
 do_page_fault+0x54/0x70 arch/x86/mm/fault.c:1460
 page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1011
RIP: 0033:0x7f83172f2786
RSP: 002b:00007fffe859ae80 EFLAGS: 00010293
RAX: 000055edd4373040 RBX: 00007f83175111c8 RCX: 000055edd4373238
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f8317510970
RBP: 00007fffe859afd0 R08: 0000000000000009 R09: 0000000000000000
R10: 0000000000000064 R11: 0000000000000000 R12: 000055edd4373040
R13: 0000000000000000 R14: 00007fffe859afe8 R15: 0000000000000000

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Apr 13, 2018
commit 3b2d69114fefa474fca542e51119036dceb4aa6f upstream.

ACPICA commit a23325b2e583556eae88ed3f764e457786bf4df6

I found some ACPI operand cache leaks in ACPI early abort cases.

Boot log of ACPI operand cache leak is as follows:
>[    0.174332] ACPI: Added _OSI(Module Device)
>[    0.175504] ACPI: Added _OSI(Processor Device)
>[    0.176010] ACPI: Added _OSI(3.0 _SCP Extensions)
>[    0.177032] ACPI: Added _OSI(Processor Aggregator Device)
>[    0.178284] ACPI: SCI (IRQ16705) allocation failed
>[    0.179352] ACPI Exception: AE_NOT_ACQUIRED, Unable to install
System Control Interrupt handler (20160930/evevent-131)
>[    0.180008] ACPI: Unable to start the ACPI Interpreter
>[    0.181125] ACPI Error: Could not remove SCI handler
(20160930/evmisc-281)
>[    0.184068] kmem_cache_destroy Acpi-Operand: Slab cache still has
objects
>[    0.185358] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.10.0-rc3 #2
>[    0.186820] Hardware name: innotek gmb_h virtual_box/virtual_box, BIOS
virtual_box 12/01/2006
>[    0.188000] Call Trace:
>[    0.188000]  ? dump_stack+0x5c/0x7d
>[    0.188000]  ? kmem_cache_destroy+0x224/0x230
>[    0.188000]  ? acpi_sleep_proc_init+0x22/0x22
>[    0.188000]  ? acpi_os_delete_cache+0xa/0xd
>[    0.188000]  ? acpi_ut_delete_caches+0x3f/0x7b
>[    0.188000]  ? acpi_terminate+0x5/0xf
>[    0.188000]  ? acpi_init+0x288/0x32e
>[    0.188000]  ? __class_create+0x4c/0x80
>[    0.188000]  ? video_setup+0x7a/0x7a
>[    0.188000]  ? do_one_initcall+0x4e/0x1b0
>[    0.188000]  ? kernel_init_freeable+0x194/0x21a
>[    0.188000]  ? rest_init+0x80/0x80
>[    0.188000]  ? kernel_init+0xa/0x100
>[    0.188000]  ? ret_from_fork+0x25/0x30

When early abort is occurred due to invalid ACPI information, Linux kernel
terminates ACPI by calling acpi_terminate() function. The function calls
acpi_ns_terminate() function to delete namespace data and ACPI operand cache
(acpi_gbl_module_code_list).

But the deletion code in acpi_ns_terminate() function is wrapped in
ACPI_EXEC_APP definition, therefore the code is only executed when the
definition exists. If the define doesn't exist, ACPI operand cache
(acpi_gbl_module_code_list) is leaked, and stack dump is shown in kernel log.

This causes a security threat because the old kernel (<= 4.9) shows memory
locations of kernel functions in stack dump, therefore kernel ASLR can be
neutralized.

To fix ACPI operand leak for enhancing security, I made a patch which
removes the ACPI_EXEC_APP define in acpi_ns_terminate() function for
executing the deletion code unconditionally.

Link: acpica/acpica@a23325b2
Signed-off-by: Seunghun Han <kkamagui@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Lee, Chun-Yi <jlee@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Apr 13, 2018
[ Upstream commit 749439bfac6e1a2932c582e2699f91d329658196 ]

The logic in __ip6_append_data() assumes that the MTU is at least large
enough for the headers.  A device's MTU may be adjusted after being
added while sendmsg() is processing data, resulting in
__ip6_append_data() seeing any MTU.  For an mtu smaller than the size of
the fragmentation header, the math results in a negative 'maxfraglen',
which causes problems when refragmenting any previous skb in the
skb_write_queue, leaving it possibly malformed.

Instead sendmsg returns EINVAL when the mtu is calculated to be less
than IPV6_MIN_MTU.

Found by syzkaller:
kernel BUG at ./include/linux/skbuff.h:2064!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 14216 Comm: syz-executor5 Not tainted 4.13.0-rc4+ #2
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d0b68580 task.stack: ffff8801ac6b8000
RIP: 0010:__skb_pull include/linux/skbuff.h:2064 [inline]
RIP: 0010:__ip6_make_skb+0x18cf/0x1f70 net/ipv6/ip6_output.c:1617
RSP: 0018:ffff8801ac6bf570 EFLAGS: 00010216
RAX: 0000000000010000 RBX: 0000000000000028 RCX: ffffc90003cce000
RDX: 00000000000001b8 RSI: ffffffff839df06f RDI: ffff8801d9478ca0
RBP: ffff8801ac6bf780 R08: ffff8801cc3f1dbc R09: 0000000000000000
R10: ffff8801ac6bf7a0 R11: 43cb4b7b1948a9e7 R12: ffff8801cc3f1dc8
R13: ffff8801cc3f1d40 R14: 0000000000001036 R15: dffffc0000000000
FS:  00007f43d740c700(0000) GS:ffff8801dc100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7834984000 CR3: 00000001d79b9000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ip6_finish_skb include/net/ipv6.h:911 [inline]
 udp_v6_push_pending_frames+0x255/0x390 net/ipv6/udp.c:1093
 udpv6_sendmsg+0x280d/0x31a0 net/ipv6/udp.c:1363
 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:762
 sock_sendmsg_nosec net/socket.c:633 [inline]
 sock_sendmsg+0xca/0x110 net/socket.c:643
 SYSC_sendto+0x352/0x5a0 net/socket.c:1750
 SyS_sendto+0x40/0x50 net/socket.c:1718
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x4512e9
RSP: 002b:00007f43d740bc08 EFLAGS: 00000216 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00000000007180a8 RCX: 00000000004512e9
RDX: 000000000000002e RSI: 0000000020d08000 RDI: 0000000000000005
RBP: 0000000000000086 R08: 00000000209c1000 R09: 000000000000001c
R10: 0000000000040800 R11: 0000000000000216 R12: 00000000004b9c69
R13: 00000000ffffffff R14: 0000000000000005 R15: 00000000202c2000
Code: 9e 01 fe e9 c5 e8 ff ff e8 7f 9e 01 fe e9 4a ea ff ff 48 89 f7 e8 52 9e 01 fe e9 aa eb ff ff e8 a8 b6 cf fd 0f 0b e8 a1 b6 cf fd <0f> 0b 49 8d 45 78 4d 8d 45 7c 48 89 85 78 fe ff ff 49 8d 85 ba
RIP: __skb_pull include/linux/skbuff.h:2064 [inline] RSP: ffff8801ac6bf570
RIP: __ip6_make_skb+0x18cf/0x1f70 net/ipv6/ip6_output.c:1617 RSP: ffff8801ac6bf570

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Mike Maloney <maloney@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang added a commit that referenced this issue Apr 13, 2018
[    5.368211] rockchip-sy-mipi-dphy ff770000.syscon:mipi-phy-rx0: invalid resource
[    5.376523] ERROR: Bad of_node_put() on /syscon@ff770000/mipi-phy-rx0/ports/port@0
[    5.384943] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.4.114 #2
[    5.391605] Hardware name: Rockchip (Device Tree)
[    5.396857] [<c0110124>] (unwind_backtrace) from [<c010bdd4>] (show_stack+0x20/0x24)
[    5.405475] [<c010bdd4>] (show_stack) from [<c050b8ec>] (dump_stack+0x84/0xa0)
[    5.413516] [<c050b8ec>] (dump_stack) from [<c08c8964>] (of_node_release+0x34/0xa4)
[    5.422035] [<c08c8964>] (of_node_release) from [<c050d8a4>] (kobject_put+0xbc/0xdc)
[    5.430649] [<c050d8a4>] (kobject_put) from [<c08c800c>] (of_node_put+0x24/0x28)
[    5.438877] [<c08c800c>] (of_node_put) from [<c08c7420>] (of_fwnode_put+0x3c/0x40)
[    5.447299] [<c08c7420>] (of_fwnode_put) from [<c0640ad4>] (fwnode_handle_put+0x38/0x3c)
[    5.456296] [<c0640ad4>] (fwnode_handle_put) from [<c0640c04>] (fwnode_graph_get_port_parent+0x4c/0x54)
[    5.466740] [<c0640c04>] (fwnode_graph_get_port_parent) from [<c078f3bc>] (__v4l2_async_notifier_parse_fwnode_endpoints+0x118/0x2bc)
[    5.479971] [<c078f3bc>] (__v4l2_async_notifier_parse_fwnode_endpoints) from [<c078f5bc>] (v4l2_async_notifier_parse_fwnode_endpoints_by_port+0x2c/0x34)
[    5.495128] [<c078f5bc>] (v4l2_async_notifier_parse_fwnode_endpoints_by_port) from [<c07c65fc>] (rockchip_mipidphy_probe+0x1b4/0x264)
[    5.508457] [<c07c65fc>] (rockchip_mipidphy_probe) from [<c063dc1c>] (platform_drv_probe+0x60/0xb0)
[    5.518513] [<c063dc1c>] (platform_drv_probe) from [<c063bda8>] (driver_probe_device+0x120/0x2a4)
[    5.528375] [<c063bda8>] (driver_probe_device) from [<c063bfa4>] (__driver_attach+0x78/0x9c)
[    5.537753] [<c063bfa4>] (__driver_attach) from [<c063a324>] (bus_for_each_dev+0x7c/0xa0)
[    5.546843] [<c063a324>] (bus_for_each_dev) from [<c063b8b8>] (driver_attach+0x28/0x30)
[    5.555741] [<c063b8b8>] (driver_attach) from [<c063b448>] (bus_add_driver+0xe0/0x1f4)
[    5.564542] [<c063b448>] (bus_add_driver) from [<c063cb28>] (driver_register+0xac/0xf0)
[    5.573443] [<c063cb28>] (driver_register) from [<c063db5c>] (__platform_driver_register+0x40/0x54)
[    5.583499] [<c063db5c>] (__platform_driver_register) from [<c123b30c>] (rockchip_isp_mipidphy_driver_init+0x18/0x20)
[    5.595287] [<c123b30c>] (rockchip_isp_mipidphy_driver_init) from [<c0101afc>] (do_one_initcall+0x114/0x1c8)
[    5.606206] [<c0101afc>] (do_one_initcall) from [<c1200edc>] (kernel_init_freeable+0x198/0x264)
[    5.615877] [<c1200edc>] (kernel_init_freeable) from [<c0c12d90>] (kernel_init+0x18/0x118)
[    5.625068] [<c0c12d90>] (kernel_init) from [<c0107690>] (ret_from_fork+0x14/0x24)

Change-Id: I6c0d625d2bfd5ffc0af6556e85d6795e9a594e98
Reviewed-on: https://tp-biosrd-v02/gerrit/82306
Reviewed-by: Jamess Huang(黃以民) <Jamess_Huang@asus.com>
Tested-by: Jamess Huang(黃以民) <Jamess_Huang@asus.com>
jamess-huang pushed a commit that referenced this issue May 14, 2018
[ Upstream commit 9b70de6d0266888b3743f03802502e43131043c8 ]

The bnx2x driver is not providing proper alignment on the receive buffers it
passes to build_skb(), causing skb_shared_info to be misaligned.
skb_shared_info contains an atomic, and while PPC normally supports
unaligned accesses, it does not support unaligned atomics.

Aligning the size of rx buffers will ensure that page_frag_alloc() returns
aligned addresses.

This can be reproduced on PPC by setting the network MTU to 1450 (or other
non-multiple-of-4) and then generating sufficient inbound network traffic
(one or two large "wget"s usually does it), producing the following oops:

Unable to handle kernel paging request for unaligned access at address 0xc00000ffc43af656
Faulting instruction address: 0xc00000000080ef8c
Oops: Kernel access of bad area, sig: 7 [#1]
SMP NR_CPUS=2048
NUMA
PowerNV
Modules linked in: vmx_crypto powernv_rng rng_core powernv_op_panel leds_powernv led_class nfsd ip_tables x_tables autofs4 xfs lpfc bnx2x mdio libcrc32c crc_t10dif crct10dif_generic crct10dif_common
CPU: 104 PID: 0 Comm: swapper/104 Not tainted 4.11.0-rc8-00088-g4c761da #2
task: c00000ffd4892400 task.stack: c00000ffd4920000
NIP: c00000000080ef8c LR: c00000000080eee8 CTR: c0000000001f8320
REGS: c00000ffffc33710 TRAP: 0600   Not tainted  (4.11.0-rc8-00088-g4c761da)
MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>
  CR: 24082042  XER: 00000000
CFAR: c00000000080eea0 DAR: c00000ffc43af656 DSISR: 00000000 SOFTE: 1
GPR00: c000000000907f64 c00000ffffc33990 c000000000dd3b00 c00000ffcaf22100
GPR04: c00000ffcaf22e00 0000000000000000 0000000000000000 0000000000000000
GPR08: 0000000000b80008 c00000ffc43af636 c00000ffc43af656 0000000000000000
GPR12: c0000000001f6f00 c00000000fe1a000 000000000000049f 000000000000c51f
GPR16: 00000000ffffef33 0000000000000000 0000000000008a43 0000000000000001
GPR20: c00000ffc58a90c0 0000000000000000 000000000000dd86 0000000000000000
GPR24: c000007fd0ed10c0 00000000ffffffff 0000000000000158 000000000000014a
GPR28: c00000ffc43af010 c00000ffc9144000 c00000ffcaf22e00 c00000ffcaf22100
NIP [c00000000080ef8c] __skb_clone+0xdc/0x140
LR [c00000000080eee8] __skb_clone+0x38/0x140
Call Trace:
[c00000ffffc33990] [c00000000080fb74] skb_clone+0x74/0x110 (unreliable)
[c00000ffffc339c0] [c000000000907f64] packet_rcv+0x144/0x510
[c00000ffffc33a40] [c000000000827b64] __netif_receive_skb_core+0x5b4/0xd80
[c00000ffffc33b00] [c00000000082b2bc] netif_receive_skb_internal+0x2c/0xc0
[c00000ffffc33b40] [c00000000082c49c] napi_gro_receive+0x11c/0x260
[c00000ffffc33b80] [d000000066483d68] bnx2x_poll+0xcf8/0x17b0 [bnx2x]
[c00000ffffc33d00] [c00000000082babc] net_rx_action+0x31c/0x480
[c00000ffffc33e10] [c0000000000d5a44] __do_softirq+0x164/0x3d0
[c00000ffffc33f00] [c0000000000d60a8] irq_exit+0x108/0x120
[c00000ffffc33f20] [c000000000015b98] __do_irq+0x98/0x200
[c00000ffffc33f90] [c000000000027f14] call_do_irq+0x14/0x24
[c00000ffd4923a90] [c000000000015d94] do_IRQ+0x94/0x110
[c00000ffd4923ae0] [c000000000008d90] hardware_interrupt_common+0x150/0x160

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue May 14, 2018
[ Upstream commit 633e8799ddc09431be2744c4a1efdbda13af2b0b ]

This changed is needed to avoid locking problem during
boot as shown:

<5>[    8.824096] Registering SWP/SWPB emulation handler
<6>[    8.977294] clock: disabling unused clocks to save power
<3>[    9.108154] BUG: sleeping function called from invalid context at kernel_albert/kernel/mutex.c:269
<3>[    9.122894] in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: swapper/0
<4>[    9.130249] 3 locks held by swapper/0/1:
<4>[    9.134613]  #0:  (&__lockdep_no_validate__){......}, at: [<c0342430>] __driver_attach+0x58/0xa8
<4>[    9.144500]  #1:  (&__lockdep_no_validate__){......}, at: [<c0342440>] __driver_attach+0x68/0xa8
<4>[    9.154357]  #2:  (&polling_timer){......}, at: [<c0053770>] run_timer_softirq+0x108/0x3ec
<4>[    9.163726] Backtrace:
<4>[    9.166473] [<c001269c>] (dump_backtrace+0x0/0x114) from [<c067e5f0>] (dump_stack+0x20/0x24)
<4>[    9.175811]  r6:00203230 r5:0000010d r4:d782e000 r3:60000113
<4>[    9.182250] [<c067e5d0>] (dump_stack+0x0/0x24) from [<c007441c>] (__might_sleep+0x10c/0x128)
<4>[    9.191650] [<c0074310>] (__might_sleep+0x0/0x128) from [<c0688f60>] (mutex_lock_nested+0x34/0x36c)
<4>[    9.201660]  r5:c02d5350 r4:d79a0c64
<4>[    9.205688] [<c0688f2c>] (mutex_lock_nested+0x0/0x36c) from [<c02d5350>] (regulator_set_current_limit+0x30/0x118)
<4>[    9.217071] [<c02d5320>] (regulator_set_current_limit+0x0/0x118) from [<c0435ce0>] (update_charger+0x84/0xc4)
<4>[    9.228027]  r7:d782fb20 r6:00000101 r5:c1767e94 r4:00000000
<4>[    9.234436] [<c0435c5c>] (update_charger+0x0/0xc4) from [<c0435d40>] (psy_changed+0x20/0x48)
<4>[    9.243804]  r5:d782e000 r4:c1767e94
<4>[    9.247802] [<c0435d20>] (psy_changed+0x0/0x48) from [<c0435dec>] (polling_timer_func+0x84/0xb8)
<4>[    9.257537]  r4:c1767e94 r3:00000002
<4>[    9.261566] [<c0435d68>] (polling_timer_func+0x0/0xb8) from [<c00537e4>] (run_timer_softirq+0x17c/0x3ec)
<4>[    9.272033]  r4:c1767eb0 r3:00000000
<4>[    9.276062] [<c0053668>] (run_timer_softirq+0x0/0x3ec) from [<c004b000>] (__do_softirq+0xf0/0x298)
<4>[    9.286010] [<c004af10>] (__do_softirq+0x0/0x298) from [<c004b650>] (irq_exit+0x98/0xa0)
<4>[    9.295013] [<c004b5b8>] (irq_exit+0x0/0xa0) from [<c000edbc>] (handle_IRQ+0x60/0xc0)
<4>[    9.303680]  r4:c1194e98 r3:c00bc778
<4>[    9.307708] [<c000ed5c>] (handle_IRQ+0x0/0xc0) from [<c0008504>] (gic_handle_irq+0x34/0x68)
<4>[    9.316955]  r8:000ac383 r7:d782fc3c r6:d782fc08 r5:c11936c4 r4:e0802100
<4>[    9.324310] r3:c026ba48
<4>[    9.327301] [<c00084d0>] (gic_handle_irq+0x0/0x68) from [<c068c2c0>] (__irq_svc+0x40/0x74)
<4>[    9.336456] Exception stack(0xd782fc08 to 0xd782fc50)
<4>[    9.342041] fc00:                   d6e30e6c ac383627 00000000 ac383417 ea19c000 ea200000
<4>[    9.351104] fc20: beffffff 00000667 000ac383 d6e30670 d6e3066c d782fc94 d782fbe8 d782fc50
<4>[    9.360168] fc40: c026ba48 c001d1f0 00000113 ffffffff

Fixes: b299804 ("[BATTERY] pda_power platform driver")
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Anthony Brandon <anthony@amarulasolutions.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue May 14, 2018
===============================
[ INFO: suspicious RCU usage. ]
4.4.120 #194 Not tainted
-------------------------------
drivers/base/power/opp/core.c:453 Missing rcu_read_lock() or opp_table_lock protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 1
3 locks held by swapper/0/1:
 #0:  (&dev->mutex){......}, at: [<ffffff80082bf1e0>] __device_attach+0x28/0x104
 #1:  (cpu_hotplug.lock){++++++}, at: [<ffffff800809aac0>] get_online_cpus+0x38/0x9c
 #2:  (subsys mutex#6){+.+.+.}, at: [<ffffff80082be46c>] subsys_interface_register+0x38/0xc4

stack backtrace:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.120 #194
Hardware name: Rockchip RK3308 evb digital-pdm mic board (DT)
Call trace:
[<ffffff8008087f08>] dump_backtrace+0x0/0x1b8
[<ffffff80080880d4>] show_stack+0x14/0x1c
[<ffffff800820ac14>] dump_stack+0xa8/0xe8
[<ffffff80080d82d8>] lockdep_rcu_suspicious+0xe4/0x10c
[<ffffff80082ce72c>] dev_pm_opp_find_freq_ceil+0x6c/0x108
[<ffffff800824d84c>] rockchip_adjust_opp_by_irdrop+0xf4/0x1e8
[<ffffff80083a66fc>] cpufreq_init+0x134/0x414
[<ffffff80083a0eec>] cpufreq_online+0x1b4/0x68c
[<ffffff80083a1464>] cpufreq_add_dev+0x3c/0x94
[<ffffff80082be4dc>] subsys_interface_register+0xa8/0xc4
[<ffffff80083a1700>] cpufreq_register_driver+0x10c/0x1a8
[<ffffff80083a6aa8>] dt_cpufreq_probe+0xcc/0xe8
[<ffffff80082c0db4>] platform_drv_probe+0x54/0xa8
[<ffffff80082bf478>] driver_probe_device+0x188/0x26c
[<ffffff80082bf694>] __device_attach_driver+0x60/0x9c
[<ffffff80082bda4c>] bus_for_each_drv+0x84/0x94
[<ffffff80082bf264>] __device_attach+0xac/0x104
[<ffffff80082bf80c>] device_initial_probe+0x10/0x18
[<ffffff80082be8e4>] bus_probe_device+0x2c/0x90
[<ffffff80082bcd48>] device_add+0x434/0x4dc
[<ffffff80082c0ad0>] platform_device_add+0xa0/0x1e4
[<ffffff80082c1520>] platform_device_register_full+0xa0/0xe0
[<ffffff800882512c>] rockchip_cpufreq_driver_init+0xb4/0x360
[<ffffff800808312c>] do_one_initcall+0xe8/0x194
[<ffffff8008810cec>] kernel_init_freeable+0x1d0/0x1d4
[<ffffff80085b8fa4>] kernel_init+0x14/0x148
[<ffffff8008082ee0>] ret_from_fork+0x10/0x30

Note: we should use dev_pm_opp_put on new kernel.

Change-Id: I39e85892f6e7994bbe4816d09e4446de5cd25cad
Signed-off-by: Tao Huang <huangtao@rock-chips.com>
jamess-huang pushed a commit that referenced this issue May 14, 2018
According to the dwc2 programmer's guide v3.10a, in '2.1.3.2 Dedicated
FIFO Mode with No Thresholding', it suggested that:

Device RxFIFO =
- Scatter/Gather DMA mode:
(4 * number of control endpoints + 6) + ((largest USB packet used / 4) +
1 for status information) + (2 * number of OUT endpoints) + 1 for Global NAK

on rockchip platforms:
(4 * 1 + 6) + ((1024 / 4) + 1) + (2 * 6) + 1 = 280

- Slave or Buffer DMA mode:
(5 * number of control endpoints + 8) + ((largest USB packet used / 4) +
1 for status information) + (2 * number of OUT endpoints) + 1 for Global NAK

on rockchip platforms:
(5 * 1 + 8) + ((1024 / 4) + 1) + (2 * 6) + 1 = 283

Device IN Endpoint TxFIFO =
The TxFIFO must equal at least one MaxPacketSize (MPS).

In addition to RxFIFO and TxFIFOs, refer to dwc2 databook v3.10a,
'Figure 2-13 Device Mode FIFO Address Mapping and AHB FIFO Access Mapping
(Dedicated FIFO)', it required that when the device is operating in non
Scatter Gather Internal DMA mode, the last locations of the SPRAM are used
to store the DMAADDR values for each Endpoint (1 location per endpoint).

When the device is operating in Scatter Gather mode, then the last locations
of the SPRAM store the Base Descriptor address, Current Descriptor address,
Current Buffer address, and status quadlet information for each endpoint
direction (4 locations per Endpoint). If an Endpoint is bidirectional , then
4 locations will be used for IN, and another 4 for OUT).

Considering that the total FIFO size of dwc2 otg is 0x3cc (972),
and we must reserve (4 * 13) = 52 locations for all Endpoints.
So reconfig dwc2 device fifo size as follows:

Device RxFIFO = 280
Device IN Endpoint TxFIFO
- FIFO #0 = (64 / 4) = 16 (Assuming this is used for EP0)
- FIFO #1 = (1024/4) = 256 (Assuming this is used for Isochronous)
- FIFO #2 = (512/4) = 128
- FIFO #3 = (512/4) = 128
- FIFO #4 = (256/4) = 64
- FIFO #5 = (128/4) = 32
- FIFO #6 = (64/4) = 16

After reconfig the dwc2 device fifo size, test mtp write on rockchip
platform (PC -> rockchip platform) on rk312x/rk3326/px30/rk3288 evb,
when mask the 'vfs_write' in f_mtp.c, the writing data rate can be
increased from 16MBps ~ 20MBps to 30MBps ~ 36MBps on different kinds
of rockchip evbs.

Change-Id: Icdf8a5dd95f96d174233e4ffc765c9a982b9f0b6
Signed-off-by: William Wu <william.wu@rock-chips.com>
jamess-huang pushed a commit that referenced this issue May 14, 2018
According to the dwc2 programmer's guide v3.10a, in '2.1.3.2 Dedicated
FIFO Mode with No Thresholding', it suggested that:

Device RxFIFO =
- Scatter/Gather DMA mode:
(4 * number of control endpoints + 6) + ((largest USB packet used / 4) +
1 for status information) + (2 * number of OUT endpoints) + 1 for Global NAK

on rockchip platforms:
(4 * 1 + 6) + ((1024 / 4) + 1) + (2 * 6) + 1 = 280

- Slave or Buffer DMA mode:
(5 * number of control endpoints + 8) + ((largest USB packet used / 4) +
1 for status information) + (2 * number of OUT endpoints) + 1 for Global NAK

on rockchip platforms:
(5 * 1 + 8) + ((1024 / 4) + 1) + (2 * 6) + 1 = 283

Device IN Endpoint TxFIFO =
The TxFIFO must equal at least one MaxPacketSize (MPS).

In addition to RxFIFO and TxFIFOs, refer to dwc2 databook v3.10a,
'Figure 2-13 Device Mode FIFO Address Mapping and AHB FIFO Access Mapping
(Dedicated FIFO)', it required that when the device is operating in non
Scatter Gather Internal DMA mode, the last locations of the SPRAM are used
to store the DMAADDR values for each Endpoint (1 location per endpoint).

When the device is operating in Scatter Gather mode, then the last locations
of the SPRAM store the Base Descriptor address, Current Descriptor address,
Current Buffer address, and status quadlet information for each endpoint
direction (4 locations per Endpoint). If an Endpoint is bidirectional , then
4 locations will be used for IN, and another 4 for OUT).

Considering that the total FIFO size of dwc2 otg is 0x3cc (972),
and we must reserve (4 * 13) = 52 locations for all Endpoints.
So reconfig dwc2 device fifo size as follows:

Device RxFIFO = 280
Device IN Endpoint TxFIFO
- FIFO #0 = (64 / 4) = 16 (Assuming this is used for EP0)
- FIFO #1 = (1024/4) = 256 (Assuming this is used for Isochronous)
- FIFO #2 = (512/4) = 128
- FIFO #3 = (512/4) = 128
- FIFO #4 = (256/4) = 64
- FIFO #5 = (128/4) = 32
- FIFO #6 = (64/4) = 16

After reconfig the dwc2 device fifo size, test mtp write on rockchip
platform (PC -> rockchip platform) on rk312x/rk3326/px30/rk3288 evb,
when mask the 'vfs_write' in f_mtp.c, the writing data rate can be
increased from 16MBps ~ 20MBps to 30MBps ~ 36MBps on different kinds
of rockchip evbs.

Change-Id: I52c64a279523c811f706e69e427b0a6e8c45683b
Signed-off-by: William Wu <william.wu@rock-chips.com>
jamess-huang pushed a commit that referenced this issue Jun 19, 2018
commit ab31fd0ce65ec93828b617123792c1bb7c6dcc42 upstream.

v4.10 commit 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race with LUN
recovery") extended accessing parent pointer fields of struct
zfcp_erp_action for tracing.  If an erp_action has never been enqueued
before, these parent pointer fields are uninitialized and NULL. Examples
are zfcp objects freshly added to the parent object's children list,
before enqueueing their first recovery subsequently. In
zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action
fields can cause a NULL pointer dereference.  Since the kernel can read
from lowcore on s390, it does not immediately cause a kernel page
fault. Instead it can cause hangs on trying to acquire the wrong
erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl()
                      ^bogus^
while holding already other locks with IRQs disabled.

Real life example from attaching lots of LUNs in parallel on many CPUs:

crash> bt 17723
PID: 17723  TASK: ...               CPU: 25  COMMAND: "zfcperp0.0.1800"
 LOWCORE INFO:
  -psw      : 0x0404300180000000 0x000000000038e424
  -function : _raw_spin_lock_wait_flags at 38e424
...
 #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp]
 #1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp]
 #2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp]
 #3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp]
 #4 [fdde8fe60] kthread at 173550
 #5 [fdde8feb8] kernel_thread_starter at 10add2

zfcp_adapter
 zfcp_port
  zfcp_unit <address>, 0x404040d600000000
  scsi_device NULL, returning early!
zfcp_scsi_dev.status = 0x40000000
0x40000000 ZFCP_STATUS_COMMON_RUNNING

crash> zfcp_unit <address>
struct zfcp_unit {
  erp_action = {
    adapter = 0x0,
    port = 0x0,
    unit = 0x0,
  },
}

zfcp_erp_action is always fully embedded into its container object. Such
container object is never moved in its object tree (only add or delete).
Hence, erp_action parent pointers can never change.

To fix the issue, initialize the erp_action parent pointers before
adding the erp_action container to any list and thus before it becomes
accessible from outside of its initializing function.

In order to also close the time window between zfcp_erp_setup_act()
memsetting the entire erp_action to zero and setting the parent pointers
again, drop the memset and instead explicitly initialize individually
all erp_action fields except for parent pointers. To be extra careful
not to introduce any other unintended side effect, even keep zeroing the
erp_action fields for list and timer. Also double-check with
WARN_ON_ONCE that erp_action parent pointers never change, so we get to
know when we would deviate from previous behavior.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 6f2ce1c6af37 ("scsi: zfcp: fix rport unblock race with LUN recovery")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Jun 19, 2018
commit 2eb9eabf1e868fda15808954fb29b0f105ed65f1 upstream.

syzkaller with KASAN reported an out-of-bounds read in
asn1_ber_decoder().  It can be reproduced by the following command,
assuming CONFIG_X509_CERTIFICATE_PARSER=y and CONFIG_KASAN=y:

    keyctl add asymmetric desc $'\x30\x30' @s

The bug is that the length of an ASN.1 data value isn't validated in the
case where it is encoded using the short form, causing the decoder to
read past the end of the input buffer.  Fix it by validating the length.

The bug report was:

    BUG: KASAN: slab-out-of-bounds in asn1_ber_decoder+0x10cb/0x1730 lib/asn1_decoder.c:233
    Read of size 1 at addr ffff88003cccfa02 by task syz-executor0/6818

    CPU: 1 PID: 6818 Comm: syz-executor0 Not tainted 4.14.0-rc7-00008-g5f479447d983 #2
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
    Call Trace:
     __dump_stack lib/dump_stack.c:16 [inline]
     dump_stack+0xb3/0x10b lib/dump_stack.c:52
     print_address_description+0x79/0x2a0 mm/kasan/report.c:252
     kasan_report_error mm/kasan/report.c:351 [inline]
     kasan_report+0x236/0x340 mm/kasan/report.c:409
     __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427
     asn1_ber_decoder+0x10cb/0x1730 lib/asn1_decoder.c:233
     x509_cert_parse+0x1db/0x650 crypto/asymmetric_keys/x509_cert_parser.c:89
     x509_key_preparse+0x64/0x7a0 crypto/asymmetric_keys/x509_public_key.c:174
     asymmetric_key_preparse+0xcb/0x1a0 crypto/asymmetric_keys/asymmetric_type.c:388
     key_create_or_update+0x347/0xb20 security/keys/key.c:855
     SYSC_add_key security/keys/keyctl.c:122 [inline]
     SyS_add_key+0x1cd/0x340 security/keys/keyctl.c:62
     entry_SYSCALL_64_fastpath+0x1f/0xbe
    RIP: 0033:0x447c89
    RSP: 002b:00007fca7a5d3bd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8
    RAX: ffffffffffffffda RBX: 00007fca7a5d46cc RCX: 0000000000447c89
    RDX: 0000000020006f4a RSI: 0000000020006000 RDI: 0000000020001ff5
    RBP: 0000000000000046 R08: fffffffffffffffd R09: 0000000000000000
    R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
    R13: 0000000000000000 R14: 00007fca7a5d49c0 R15: 00007fca7a5d4700

Fixes: 42d5ec2 ("X.509: Add an ASN.1 decoder")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Jun 19, 2018
commit 624f5ab8720b3371367327a822c267699c1823b8 upstream.

syzkaller reported a NULL pointer dereference in asn1_ber_decoder().  It
can be reproduced by the following command, assuming
CONFIG_PKCS7_TEST_KEY=y:

        keyctl add pkcs7_test desc '' @s

The bug is that if the data buffer is empty, an integer underflow occurs
in the following check:

        if (unlikely(dp >= datalen - 1))
                goto data_overrun_error;

This results in the NULL data pointer being dereferenced.

Fix it by checking for 'datalen - dp < 2' instead.

Also fix the similar check for 'dp >= datalen - n' later in the same
function.  That one possibly could result in a buffer overread.

The NULL pointer dereference was reproducible using the "pkcs7_test" key
type but not the "asymmetric" key type because the "asymmetric" key type
checks for a 0-length payload before calling into the ASN.1 decoder but
the "pkcs7_test" key type does not.

The bug report was:

    BUG: unable to handle kernel NULL pointer dereference at           (null)
    IP: asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233
    PGD 7b708067 P4D 7b708067 PUD 7b6ee067 PMD 0
    Oops: 0000 [#1] SMP
    Modules linked in:
    CPU: 0 PID: 522 Comm: syz-executor1 Not tainted 4.14.0-rc8 #7
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.3-20171021_125229-anatol 04/01/2014
    task: ffff9b6b3798c040 task.stack: ffff9b6b37970000
    RIP: 0010:asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233
    RSP: 0018:ffff9b6b37973c78 EFLAGS: 00010216
    RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000021c
    RDX: ffffffff814a04ed RSI: ffffb1524066e000 RDI: ffffffff910759e0
    RBP: ffff9b6b37973d60 R08: 0000000000000001 R09: ffff9b6b3caa4180
    R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
    R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
    FS:  00007f10ed1f2700(0000) GS:ffff9b6b3ea00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 000000007b6f3000 CR4: 00000000000006f0
    Call Trace:
     pkcs7_parse_message+0xee/0x240 crypto/asymmetric_keys/pkcs7_parser.c:139
     verify_pkcs7_signature+0x33/0x180 certs/system_keyring.c:216
     pkcs7_preparse+0x41/0x70 crypto/asymmetric_keys/pkcs7_key_type.c:63
     key_create_or_update+0x180/0x530 security/keys/key.c:855
     SYSC_add_key security/keys/keyctl.c:122 [inline]
     SyS_add_key+0xbf/0x250 security/keys/keyctl.c:62
     entry_SYSCALL_64_fastpath+0x1f/0xbe
    RIP: 0033:0x4585c9
    RSP: 002b:00007f10ed1f1bd8 EFLAGS: 00000216 ORIG_RAX: 00000000000000f8
    RAX: ffffffffffffffda RBX: 00007f10ed1f2700 RCX: 00000000004585c9
    RDX: 0000000020000000 RSI: 0000000020008ffb RDI: 0000000020008000
    RBP: 0000000000000000 R08: ffffffffffffffff R09: 0000000000000000
    R10: 0000000000000000 R11: 0000000000000216 R12: 00007fff1b2260ae
    R13: 00007fff1b2260af R14: 00007f10ed1f2700 R15: 0000000000000000
    Code: dd ca ff 48 8b 45 88 48 83 e8 01 4c 39 f0 0f 86 a8 07 00 00 e8 53 dd ca ff 49 8d 46 01 48 89 85 58 ff ff ff 48 8b 85 60 ff ff ff <42> 0f b6 0c 30 89 c8 88 8d 75 ff ff ff 83 e0 1f 89 8d 28 ff ff
    RIP: asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233 RSP: ffff9b6b37973c78
    CR2: 0000000000000000

Fixes: 42d5ec2 ("X.509: Add an ASN.1 decoder")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Jun 28, 2018
[ Upstream commit d754941225a7dbc61f6dd2173fa9498049f9a7ee ]

If, for any reason, userland shuts down iscsi transport interfaces
before proper logouts - like when logging in to LUNs manually, without
logging out on server shutdown, or when automated scripts can't
umount/logout from logged LUNs - kernel will hang forever on its
sd_sync_cache() logic, after issuing the SYNCHRONIZE_CACHE cmd to all
still existent paths.

PID: 1 TASK: ffff8801a69b8000 CPU: 1 COMMAND: "systemd-shutdow"
 #0 [ffff8801a69c3a30] __schedule at ffffffff8183e9ee
 #1 [ffff8801a69c3a80] schedule at ffffffff8183f0d5
 #2 [ffff8801a69c3a98] schedule_timeout at ffffffff81842199
 #3 [ffff8801a69c3b40] io_schedule_timeout at ffffffff8183e604
 #4 [ffff8801a69c3b70] wait_for_completion_io_timeout at ffffffff8183fc6c
 #5 [ffff8801a69c3bd0] blk_execute_rq at ffffffff813cfe10
 #6 [ffff8801a69c3c88] scsi_execute at ffffffff815c3fc7
 #7 [ffff8801a69c3cc8] scsi_execute_req_flags at ffffffff815c60fe
 #8 [ffff8801a69c3d30] sd_sync_cache at ffffffff815d37d7
 #9 [ffff8801a69c3da8] sd_shutdown at ffffffff815d3c3c

This happens because iscsi_eh_cmd_timed_out(), the transport layer
timeout helper, would tell the queue timeout function (scsi_times_out)
to reset the request timer over and over, until the session state is
back to logged in state. Unfortunately, during server shutdown, this
might never happen again.

Other option would be "not to handle" the issue in the transport
layer. That would trigger the error handler logic, which would also need
the session state to be logged in again.

Best option, for such case, is to tell upper layers that the command was
handled during the transport layer error handler helper, marking it as
DID_NO_CONNECT, which will allow completion and inform about the
problem.

After the session was marked as ISCSI_STATE_FAILED, due to the first
timeout during the server shutdown phase, all subsequent cmds will fail
to be queued, allowing upper logic to fail faster.

Signed-off-by: Rafael David Tinoco <rafael.tinoco@canonical.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Jun 28, 2018
commit c755e251357a0cee0679081f08c3f4ba797a8009 upstream.

The xattr_sem deadlock problems fixed in commit 2e81a4eeedca: "ext4:
avoid deadlock when expanding inode size" didn't include the use of
xattr_sem in fs/ext4/inline.c.  With the addition of project quota
which added a new extra inode field, this exposed deadlocks in the
inline_data code similar to the ones fixed by 2e81a4eeedca.

The deadlock can be reproduced via:

   dmesg -n 7
   mke2fs -t ext4 -O inline_data -Fq -I 256 /dev/vdc 32768
   mount -t ext4 -o debug_want_extra_isize=24 /dev/vdc /vdc
   mkdir /vdc/a
   umount /vdc
   mount -t ext4 /dev/vdc /vdc
   echo foo > /vdc/a/foo

and looks like this:

[   11.158815]
[   11.160276] =============================================
[   11.161960] [ INFO: possible recursive locking detected ]
[   11.161960] 4.10.0-rc3-00015-g011b30a8a3cf #160 Tainted: G        W
[   11.161960] ---------------------------------------------
[   11.161960] bash/2519 is trying to acquire lock:
[   11.161960]  (&ei->xattr_sem){++++..}, at: [<c1225a4b>] ext4_expand_extra_isize_ea+0x3d/0x4cd
[   11.161960]
[   11.161960] but task is already holding lock:
[   11.161960]  (&ei->xattr_sem){++++..}, at: [<c1227941>] ext4_try_add_inline_entry+0x3a/0x152
[   11.161960]
[   11.161960] other info that might help us debug this:
[   11.161960]  Possible unsafe locking scenario:
[   11.161960]
[   11.161960]        CPU0
[   11.161960]        ----
[   11.161960]   lock(&ei->xattr_sem);
[   11.161960]   lock(&ei->xattr_sem);
[   11.161960]
[   11.161960]  *** DEADLOCK ***
[   11.161960]
[   11.161960]  May be due to missing lock nesting notation
[   11.161960]
[   11.161960] 4 locks held by bash/2519:
[   11.161960]  #0:  (sb_writers#3){.+.+.+}, at: [<c11a2414>] mnt_want_write+0x1e/0x3e
[   11.161960]  #1:  (&type->i_mutex_dir_key){++++++}, at: [<c119508b>] path_openat+0x338/0x67a
[   11.161960]  #2:  (jbd2_handle){++++..}, at: [<c123314a>] start_this_handle+0x582/0x622
[   11.161960]  #3:  (&ei->xattr_sem){++++..}, at: [<c1227941>] ext4_try_add_inline_entry+0x3a/0x152
[   11.161960]
[   11.161960] stack backtrace:
[   11.161960] CPU: 0 PID: 2519 Comm: bash Tainted: G        W       4.10.0-rc3-00015-g011b30a8a3cf #160
[   11.161960] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1 04/01/2014
[   11.161960] Call Trace:
[   11.161960]  dump_stack+0x72/0xa3
[   11.161960]  __lock_acquire+0xb7c/0xcb9
[   11.161960]  ? kvm_clock_read+0x1f/0x29
[   11.161960]  ? __lock_is_held+0x36/0x66
[   11.161960]  ? __lock_is_held+0x36/0x66
[   11.161960]  lock_acquire+0x106/0x18a
[   11.161960]  ? ext4_expand_extra_isize_ea+0x3d/0x4cd
[   11.161960]  down_write+0x39/0x72
[   11.161960]  ? ext4_expand_extra_isize_ea+0x3d/0x4cd
[   11.161960]  ext4_expand_extra_isize_ea+0x3d/0x4cd
[   11.161960]  ? _raw_read_unlock+0x22/0x2c
[   11.161960]  ? jbd2_journal_extend+0x1e2/0x262
[   11.161960]  ? __ext4_journal_get_write_access+0x3d/0x60
[   11.161960]  ext4_mark_inode_dirty+0x17d/0x26d
[   11.161960]  ? ext4_add_dirent_to_inline.isra.12+0xa5/0xb2
[   11.161960]  ext4_add_dirent_to_inline.isra.12+0xa5/0xb2
[   11.161960]  ext4_try_add_inline_entry+0x69/0x152
[   11.161960]  ext4_add_entry+0xa3/0x848
[   11.161960]  ? __brelse+0x14/0x2f
[   11.161960]  ? _raw_spin_unlock_irqrestore+0x44/0x4f
[   11.161960]  ext4_add_nondir+0x17/0x5b
[   11.161960]  ext4_create+0xcf/0x133
[   11.161960]  ? ext4_mknod+0x12f/0x12f
[   11.161960]  lookup_open+0x39e/0x3fb
[   11.161960]  ? __wake_up+0x1a/0x40
[   11.161960]  ? lock_acquire+0x11e/0x18a
[   11.161960]  path_openat+0x35c/0x67a
[   11.161960]  ? sched_clock_cpu+0xd7/0xf2
[   11.161960]  do_filp_open+0x36/0x7c
[   11.161960]  ? _raw_spin_unlock+0x22/0x2c
[   11.161960]  ? __alloc_fd+0x169/0x173
[   11.161960]  do_sys_open+0x59/0xcc
[   11.161960]  SyS_open+0x1d/0x1f
[   11.161960]  do_int80_syscall_32+0x4f/0x61
[   11.161960]  entry_INT80_32+0x2f/0x2f
[   11.161960] EIP: 0xb76ad469
[   11.161960] EFLAGS: 00000286 CPU: 0
[   11.161960] EAX: ffffffda EBX: 08168ac8 ECX: 00008241 EDX: 000001b6
[   11.161960] ESI: b75e46bc EDI: b7755000 EBP: bfbdb108 ESP: bfbdafc0
[   11.161960]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b

Cc: stable@vger.kernel.org # 3.10 (requires 2e81a4eeedca as a prereq)
Reported-by: George Spelvin <linux@sciencehorizons.net>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Jun 28, 2018
[ Upstream commit 9c438d7a3a52dcc2b9ed095cb87d3a5e83cf7e60 ]

Adding a dns_resolver key whose payload contains a very long option name
resulted in that string being printed in full.  This hit the WARN_ONCE()
in set_precision() during the printk(), because printk() only supports a
precision of up to 32767 bytes:

    precision 1000000 too large
    WARNING: CPU: 0 PID: 752 at lib/vsprintf.c:2189 vsnprintf+0x4bc/0x5b0

Fix it by limiting option strings (combined name + value) to a much more
reasonable 128 bytes.  The exact limit is arbitrary, but currently the
only recognized option is formatted as "dnserror=%lu" which fits well
within this limit.

Also ratelimit the printks.

Reproducer:

    perl -e 'print "#", "A" x 1000000, "\x00"' | keyctl padd dns_resolver desc @s

This bug was found using syzkaller.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 4a2d789 ("DNS: If the DNS server returns an error, allow that to be cached [ver #2]")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jamess-huang pushed a commit that referenced this issue Jun 28, 2018
commit 5c64576a77894a50be80be0024bed27171b55989 upstream.

syzkaller reports for wrong rtnl_lock usage in sync code [1] and [2]

We have 2 problems in start_sync_thread if error path is
taken, eg. on memory allocation error or failure to configure
sockets for mcast group or addr/port binding:

1. recursive locking: holding rtnl_lock while calling sock_release
which in turn calls again rtnl_lock in ip_mc_drop_socket to leave
the mcast group, as noticed by Florian Westphal. Additionally,
sock_release can not be called while holding sync_mutex (ABBA
deadlock).

2. task hung: holding rtnl_lock while calling kthread_stop to
stop the running kthreads. As the kthreads do the same to leave
the mcast group (sock_release -> ip_mc_drop_socket -> rtnl_lock)
they hang.

Fix the problems by calling rtnl_unlock early in the error path,
now sock_release is called after unlocking both mutexes.

Problem 3 (task hung reported by syzkaller [2]) is variant of
problem 2: use _trylock to prevent one user to call rtnl_lock and
then while waiting for sync_mutex to block kthreads that execute
sock_release when they are stopped by stop_sync_thread.

[1]
IPVS: stopping backup sync thread 4500 ...
WARNING: possible recursive locking detected
4.16.0-rc7+ #3 Not tainted
--------------------------------------------
syzkaller688027/4497 is trying to acquire lock:
  (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

but task is already holding lock:
IPVS: stopping backup sync thread 4495 ...
  (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(rtnl_mutex);
   lock(rtnl_mutex);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

2 locks held by syzkaller688027/4497:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000bb14d7fb>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
  #1:  (ipvs->sync_mutex){+.+.}, at: [<00000000703f78e3>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388

stack backtrace:
CPU: 1 PID: 4497 Comm: syzkaller688027 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x24d lib/dump_stack.c:53
  print_deadlock_bug kernel/locking/lockdep.c:1761 [inline]
  check_deadlock kernel/locking/lockdep.c:1805 [inline]
  validate_chain kernel/locking/lockdep.c:2401 [inline]
  __lock_acquire+0xe8f/0x3e00 kernel/locking/lockdep.c:3431
  lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:3920
  __mutex_lock_common kernel/locking/mutex.c:756 [inline]
  __mutex_lock+0x16f/0x1a80 kernel/locking/mutex.c:893
  mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908
  rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74
  ip_mc_drop_socket+0x88/0x230 net/ipv4/igmp.c:2643
  inet_release+0x4e/0x1c0 net/ipv4/af_inet.c:413
  sock_release+0x8d/0x1e0 net/socket.c:595
  start_sync_thread+0x2213/0x2b70 net/netfilter/ipvs/ip_vs_sync.c:1924
  do_ip_vs_set_ctl+0x1139/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2389
  nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
  nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
  ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1261
  udp_setsockopt+0x45/0x80 net/ipv4/udp.c:2406
  sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2975
  SYSC_setsockopt net/socket.c:1849 [inline]
  SyS_setsockopt+0x189/0x360 net/socket.c:1828
  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x446a69
RSP: 002b:00007fa1c3a64da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446a69
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000006e29fc R08: 0000000000000018 R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 00000000006e29f8
R13: 00676e697279656b R14: 00007fa1c3a659c0 R15: 00000000006e2b60

[2]
IPVS: sync thread started: state = BACKUP, mcast_ifn = syz_tun, syncid = 4,
id = 0
IPVS: stopping backup sync thread 25415 ...
INFO: task syz-executor7:25421 blocked for more than 120 seconds.
       Not tainted 4.16.0-rc6+ #284
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D23688 25421   4408 0x00000004
Call Trace:
  context_switch kernel/sched/core.c:2862 [inline]
  __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
  schedule+0xf5/0x430 kernel/sched/core.c:3499
  schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777
  do_wait_for_common kernel/sched/completion.c:86 [inline]
  __wait_for_common kernel/sched/completion.c:107 [inline]
  wait_for_common kernel/sched/completion.c:118 [inline]
  wait_for_completion+0x415/0x770 kernel/sched/completion.c:139
  kthread_stop+0x14a/0x7a0 kernel/kthread.c:530
  stop_sync_thread+0x3d9/0x740 net/netfilter/ipvs/ip_vs_sync.c:1996
  do_ip_vs_set_ctl+0x2b1/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2394
  nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
  nf_setsockopt+0x67/0xc0 net/netfilter/nf_sockopt.c:115
  ip_setsockopt+0x97/0xa0 net/ipv4/ip_sockglue.c:1253
  sctp_setsockopt+0x2ca/0x63e0 net/sctp/socket.c:4154
  sock_common_setsockopt+0x95/0xd0 net/core/sock.c:3039
  SYSC_setsockopt net/socket.c:1850 [inline]
  SyS_setsockopt+0x189/0x360 net/socket.c:1829
  do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454889
RSP: 002b:00007fc927626c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fc9276276d4 RCX: 0000000000454889
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000017
RBP: 000000000072bf58 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000051c R14: 00000000006f9b40 R15: 0000000000000001

Showing all locks held in the system:
2 locks held by khungtaskd/868:
  #0:  (rcu_read_lock){....}, at: [<00000000a1a8f002>]
check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
  #0:  (rcu_read_lock){....}, at: [<00000000a1a8f002>] watchdog+0x1c5/0xd60
kernel/hung_task.c:249
  #1:  (tasklist_lock){.+.+}, at: [<0000000037c2f8f9>]
debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4247:
  #0:  (&f->f_pos_lock){+.+.}, at: [<000000000d8d6983>]
__fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4338:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4342:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4343:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4344:
  #0:  (&tty->ldisc_sem){++++}, at: [<00000000bee98654>]
ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
  #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000c1d180aa>]
n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/0:5/6494:
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] work_static include/linux/workqueue.h:198 [inline]
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_data kernel/workqueue.c:619 [inline]
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] set_work_pool_and_clear_pending kernel/workqueue.c:646
[inline]
  #0:  ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
[<00000000a062b18e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
  #1:  ((addr_chk_work).work){+.+.}, at: [<00000000278427d5>]
process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
  #2:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by syz-executor7/25421:
  #0:  (ipvs->sync_mutex){+.+.}, at: [<00000000d414a689>]
do_ip_vs_set_ctl+0x277/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2393
2 locks held by syz-executor7/25427:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
  #1:  (ipvs->sync_mutex){+.+.}, at: [<00000000e6d48489>]
do_ip_vs_set_ctl+0x10f8/0x1cc0 net/netfilter/ipvs/ip_vs_ctl.c:2388
1 lock held by syz-executor7/25435:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74
1 lock held by ipvs-b:2:0/25415:
  #0:  (rtnl_mutex){+.+.}, at: [<00000000066e35ac>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

Reported-and-tested-by: syzbot+a46d6abf9d56b1365a72@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+5fe074c01b2032ce9618@syzkaller.appspotmail.com
Fixes: e0b26cc ("ipvs: call rtnl_lock early")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Zubin Mithra <zsm@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
[ Upstream commit fba9eb7946251d6e420df3bdf7bc45195be7be9a ]

Add a header with macros usable in assembler files to emit alternative
code sequences. It works analog to the alternatives for inline assmeblies
in C files, with the same restrictions and capabilities.
The syntax is

     ALTERNATIVE "<default instructions sequence>", \
		 "<alternative instructions sequence>", \
		 "<features-bit>"
and

     ALTERNATIVE_2 "<default instructions sequence>", \
		   "<alternative instructions sqeuence TinkerBoard#1>", \
		   "<feature-bit TinkerBoard#1>",
		   "<alternative instructions sqeuence TinkerBoard#2>", \
		   "<feature-bit TinkerBoard#2>"

Reviewed-by: Vasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
[ Upstream commit 2c0aa08631b86a4678dbc93b9caa5248014b4458 ]

Scenario:
1. Port down and do fail over
2. Ap do rds_bind syscall

PID: 47039  TASK: ffff89887e2fe640  CPU: 47  COMMAND: "kworker/u:6"
 #0 [ffff898e35f159f0] machine_kexec at ffffffff8103abf9
 TinkerBoard#1 [ffff898e35f15a60] crash_kexec at ffffffff810b96e3
 TinkerBoard#2 [ffff898e35f15b30] oops_end at ffffffff8150f518
 TinkerBoard#3 [ffff898e35f15b60] no_context at ffffffff8104854c
 TinkerBoard#4 [ffff898e35f15ba0] __bad_area_nosemaphore at ffffffff81048675
 TinkerBoard#5 [ffff898e35f15bf0] bad_area_nosemaphore at ffffffff810487d3
 TinkerBoard#6 [ffff898e35f15c00] do_page_fault at ffffffff815120b8
 TinkerBoard#7 [ffff898e35f15d10] page_fault at ffffffff8150ea95
    [exception RIP: unknown or invalid address]
    RIP: 0000000000000000  RSP: ffff898e35f15dc8  RFLAGS: 00010282
    RAX: 00000000fffffffe  RBX: ffff889b77f6fc00  RCX:ffffffff81c99d88
    RDX: 0000000000000000  RSI: ffff896019ee08e8  RDI:ffff889b77f6fc00
    RBP: ffff898e35f15df0   R8: ffff896019ee08c8  R9:0000000000000000
    R10: 0000000000000400  R11: 0000000000000000  R12:ffff896019ee08c0
    R13: ffff889b77f6fe68  R14: ffffffff81c99d80  R15: ffffffffa022a1e0
    ORIG_RAX: ffffffffffffffff  CS: 0010 SS: 0018
 TinkerBoard#8 [ffff898e35f15dc8] cma_ndev_work_handler at ffffffffa022a228 [rdma_cm]
 TinkerBoard#9 [ffff898e35f15df8] process_one_work at ffffffff8108a7c6
 TinkerBoard#10 [ffff898e35f15e58] worker_thread at ffffffff8108bda0
 TinkerBoard#11 [ffff898e35f15ee8] kthread at ffffffff81090fe6

PID: 45659  TASK: ffff880d313d2500  CPU: 31  COMMAND: "oracle_45659_ap"
 #0 [ffff881024ccfc98] __schedule at ffffffff8150bac4
 TinkerBoard#1 [ffff881024ccfd40] schedule at ffffffff8150c2cf
 TinkerBoard#2 [ffff881024ccfd50] __mutex_lock_slowpath at ffffffff8150cee7
 TinkerBoard#3 [ffff881024ccfdc0] mutex_lock at ffffffff8150cdeb
 TinkerBoard#4 [ffff881024ccfde0] rdma_destroy_id at ffffffffa022a027 [rdma_cm]
 TinkerBoard#5 [ffff881024ccfe10] rds_ib_laddr_check at ffffffffa0357857 [rds_rdma]
 TinkerBoard#6 [ffff881024ccfe50] rds_trans_get_preferred at ffffffffa0324c2a [rds]
 TinkerBoard#7 [ffff881024ccfe80] rds_bind at ffffffffa031d690 [rds]
 TinkerBoard#8 [ffff881024ccfeb0] sys_bind at ffffffff8142a670

PID: 45659                          PID: 47039
rds_ib_laddr_check
  /* create id_priv with a null event_handler */
  rdma_create_id
  rdma_bind_addr
    cma_acquire_dev
      /* add id_priv to cma_dev->id_list */
      cma_attach_to_dev
                                    cma_ndev_work_handler
                                      /* event_hanlder is null */
                                      id_priv->id.event_handler

Signed-off-by: Guanglei Li <guanglei.li@oracle.com>
Signed-off-by: Honglei Wang <honglei.wang@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Yanjun Zhu <yanjun.zhu@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
[ Upstream commit b6dd4d83dc2f78cebc9a7e6e7e4bc2be4d29b94d ]

The pr_debug() in gic-v3 gic_send_sgi() can trigger a circular locking
warning:

 GICv3: CPU10: ICC_SGI1R_EL1 5000400
 ======================================================
 WARNING: possible circular locking dependency detected
 4.15.0+ TinkerBoard#1 Tainted: G        W
 ------------------------------------------------------
 dynamic_debug01/1873 is trying to acquire lock:
  ((console_sem).lock){-...}, at: [<0000000099c891ec>] down_trylock+0x20/0x4c

 but task is already holding lock:
  (&rq->lock){-.-.}, at: [<00000000842e1587>] __task_rq_lock+0x54/0xdc

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> TinkerBoard#2 (&rq->lock){-.-.}:
        __lock_acquire+0x3b4/0x6e0
        lock_acquire+0xf4/0x2a8
        _raw_spin_lock+0x4c/0x60
        task_fork_fair+0x3c/0x148
        sched_fork+0x10c/0x214
        copy_process.isra.32.part.33+0x4e8/0x14f0
        _do_fork+0xe8/0x78c
        kernel_thread+0x48/0x54
        rest_init+0x34/0x2a4
        start_kernel+0x45c/0x488

 -> TinkerBoard#1 (&p->pi_lock){-.-.}:
        __lock_acquire+0x3b4/0x6e0
        lock_acquire+0xf4/0x2a8
        _raw_spin_lock_irqsave+0x58/0x70
        try_to_wake_up+0x48/0x600
        wake_up_process+0x28/0x34
        __up.isra.0+0x60/0x6c
        up+0x60/0x68
        __up_console_sem+0x4c/0x7c
        console_unlock+0x328/0x634
        vprintk_emit+0x25c/0x390
        dev_vprintk_emit+0xc4/0x1fc
        dev_printk_emit+0x88/0xa8
        __dev_printk+0x58/0x9c
        _dev_info+0x84/0xa8
        usb_new_device+0x100/0x474
        hub_port_connect+0x280/0x92c
        hub_event+0x740/0xa84
        process_one_work+0x240/0x70c
        worker_thread+0x60/0x400
        kthread+0x110/0x13c
        ret_from_fork+0x10/0x18

 -> #0 ((console_sem).lock){-...}:
        validate_chain.isra.34+0x6e4/0xa20
        __lock_acquire+0x3b4/0x6e0
        lock_acquire+0xf4/0x2a8
        _raw_spin_lock_irqsave+0x58/0x70
        down_trylock+0x20/0x4c
        __down_trylock_console_sem+0x3c/0x9c
        console_trylock+0x20/0xb0
        vprintk_emit+0x254/0x390
        vprintk_default+0x58/0x90
        vprintk_func+0xbc/0x164
        printk+0x80/0xa0
        __dynamic_pr_debug+0x84/0xac
        gic_raise_softirq+0x184/0x18c
        smp_cross_call+0xac/0x218
        smp_send_reschedule+0x3c/0x48
        resched_curr+0x60/0x9c
        check_preempt_curr+0x70/0xdc
        wake_up_new_task+0x310/0x470
        _do_fork+0x188/0x78c
        SyS_clone+0x44/0x50
        __sys_trace_return+0x0/0x4

 other info that might help us debug this:

 Chain exists of:
   (console_sem).lock --> &p->pi_lock --> &rq->lock

  Possible unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(&rq->lock);
                                lock(&p->pi_lock);
                                lock(&rq->lock);
   lock((console_sem).lock);

  *** DEADLOCK ***

 2 locks held by dynamic_debug01/1873:
  #0:  (&p->pi_lock){-.-.}, at: [<000000001366df53>] wake_up_new_task+0x40/0x470
  TinkerBoard#1:  (&rq->lock){-.-.}, at: [<00000000842e1587>] __task_rq_lock+0x54/0xdc

 stack backtrace:
 CPU: 10 PID: 1873 Comm: dynamic_debug01 Tainted: G        W        4.15.0+ TinkerBoard#1
 Hardware name: GIGABYTE R120-T34-00/MT30-GS2-00, BIOS T48 10/02/2017
 Call trace:
  dump_backtrace+0x0/0x188
  show_stack+0x24/0x2c
  dump_stack+0xa4/0xe0
  print_circular_bug.isra.31+0x29c/0x2b8
  check_prev_add.constprop.39+0x6c8/0x6dc
  validate_chain.isra.34+0x6e4/0xa20
  __lock_acquire+0x3b4/0x6e0
  lock_acquire+0xf4/0x2a8
  _raw_spin_lock_irqsave+0x58/0x70
  down_trylock+0x20/0x4c
  __down_trylock_console_sem+0x3c/0x9c
  console_trylock+0x20/0xb0
  vprintk_emit+0x254/0x390
  vprintk_default+0x58/0x90
  vprintk_func+0xbc/0x164
  printk+0x80/0xa0
  __dynamic_pr_debug+0x84/0xac
  gic_raise_softirq+0x184/0x18c
  smp_cross_call+0xac/0x218
  smp_send_reschedule+0x3c/0x48
  resched_curr+0x60/0x9c
  check_preempt_curr+0x70/0xdc
  wake_up_new_task+0x310/0x470
  _do_fork+0x188/0x78c
  SyS_clone+0x44/0x50
  __sys_trace_return+0x0/0x4
 GICv3: CPU0: ICC_SGI1R_EL1 12000

This could be fixed with printk_deferred() but that might lessen its
usefulness for debugging. So change it to pr_devel to keep it out of
production kernels. Developers working on gic-v3 can enable it as
needed in their kernels.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
[ Upstream commit 2bbea6e117357d17842114c65e9a9cf2d13ae8a3 ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 TinkerBoard#1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 TinkerBoard#2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 TinkerBoard#3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 TinkerBoard#4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 TinkerBoard#5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 TinkerBoard#6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 TinkerBoard#7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 TinkerBoard#8 [ffff880078447da8] mount_bdev at ffffffff81202570
 TinkerBoard#9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
TinkerBoard#10 [ffff880078447e28] mount_fs at ffffffff81202d09
TinkerBoard#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
TinkerBoard#12 [ffff880078447ea8] do_mount at ffffffff81220fee
TinkerBoard#13 [ffff880078447f28] sys_mount at ffffffff812218d6
TinkerBoard#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 TinkerBoard#1 [ffff880078417900] schedule at ffffffff8168dc59
 TinkerBoard#2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 TinkerBoard#3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 TinkerBoard#4 [ffff8800784179d0] down_read at ffffffff8168cde0
 TinkerBoard#5 [ffff8800784179e8] get_super at ffffffff81201cc7
 TinkerBoard#6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 TinkerBoard#7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 TinkerBoard#8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 TinkerBoard#9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
TinkerBoard#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
TinkerBoard#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
TinkerBoard#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
TinkerBoard#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
TinkerBoard#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
TinkerBoard#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
TinkerBoard#16 [ffff880078417d00] do_last at ffffffff8120d53d
TinkerBoard#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
TinkerBoard#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
TinkerBoard#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
TinkerBoard#20 [ffff880078417f70] sys_open at ffffffff811fde4e
TinkerBoard#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
[ Upstream commit a3ca831249ca8c4c226e4ceafee04e280152e59d ]

When booting up with "threadirqs" in command line, all irq handlers of the DMA
controller pl330 will be threaded forcedly. These threads will race for the same
list, pl330->req_done.

Before the callback, the spinlock was released. And after it, the spinlock was
taken. This opened an race window where another threaded irq handler could steal
the spinlock and be permitted to delete entries of the list, pl330->req_done.

If the later deleted an entry that was still referred to by the former, there would
be a kernel panic when the former was scheduled and tried to get the next sibling
of the deleted entry.

The scenario could be depicted as below:

  Thread: T1  pl330->req_done  Thread: T2
      |             |              |
      |          -A-B-C-D-         |
    Locked          |              |
      |             |           Waiting
    Del A           |              |
      |          -B-C-D-           |
    Unlocked        |              |
      |             |           Locked
    Waiting         |              |
      |             |            Del B
      |             |              |
      |           -C-D-         Unlocked
    Waiting         |              |
      |
    Locked
      |
   get C via B
      \
       - Kernel panic

The kernel panic looked like as below:

Unable to handle kernel paging request at virtual address dead000000000108
pgd = ffffff8008c9e000
[dead000000000108] *pgd=000000027fffe003, *pud=000000027fffe003, *pmd=0000000000000000
Internal error: Oops: 96000044 [TinkerBoard#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 85 Comm: irq/59-66330000 Not tainted 4.8.24-WR9.0.0.12_standard TinkerBoard#2
Hardware name: Broadcom NS2 SVK (DT)
task: ffffffc1f5cc3c00 task.stack: ffffffc1f5ce0000
PC is at pl330_irq_handler+0x27c/0x390
LR is at pl330_irq_handler+0x2a8/0x390
pc : [<ffffff80084cb694>] lr : [<ffffff80084cb6c0>] pstate: 800001c5
sp : ffffffc1f5ce3d00
x29: ffffffc1f5ce3d00 x28: 0000000000000140
x27: ffffffc1f5c530b0 x26: dead000000000100
x25: dead000000000200 x24: 0000000000418958
x23: 0000000000000001 x22: ffffffc1f5ccd668
x21: ffffffc1f5ccd590 x20: ffffffc1f5ccd418
x19: dead000000000060 x18: 0000000000000001
x17: 0000000000000007 x16: 0000000000000001
x15: ffffffffffffffff x14: ffffffffffffffff
x13: ffffffffffffffff x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000840
x9 : ffffffc1f5ce0000 x8 : ffffffc1f5cc3338
x7 : ffffff8008ce2020 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001
x3 : dead000000000200 x2 : dead000000000100
x1 : 0000000000000140 x0 : ffffffc1f5ccd590

Process irq/59-66330000 (pid: 85, stack limit = 0xffffffc1f5ce0020)
Stack: (0xffffffc1f5ce3d00 to 0xffffffc1f5ce4000)
3d00: ffffffc1f5ce3d80 ffffff80080f09d0 ffffffc1f5ca0c00 ffffffc1f6f7c600
3d20: ffffffc1f5ce0000 ffffffc1f6f7c600 ffffffc1f5ca0c00 ffffff80080f0998
3d40: ffffffc1f5ce0000 ffffff80080f0000 0000000000000000 0000000000000000
3d60: ffffff8008ce202c ffffff8008ce2020 ffffffc1f5ccd668 ffffffc1f5c530b0
3d80: ffffffc1f5ce3db0 ffffff80080f0d70 ffffffc1f5ca0c40 0000000000000001
3da0: ffffffc1f5ce0000 ffffff80080f0cfc ffffffc1f5ce3e20 ffffff80080bf4f8
3dc0: ffffffc1f5ca0c80 ffffff8008bf3798 ffffff8008955528 ffffffc1f5ca0c00
3de0: ffffff80080f0c30 0000000000000000 0000000000000000 0000000000000000
3e00: 0000000000000000 0000000000000000 0000000000000000 ffffff80080f0b68
3e20: 0000000000000000 ffffff8008083690 ffffff80080bf420 ffffffc1f5ca0c80
3e40: 0000000000000000 0000000000000000 0000000000000000 ffffff80080cb648
3e60: ffffff8008b1c780 0000000000000000 0000000000000000 ffffffc1f5ca0c00
3e80: ffffffc100000000 ffffff8000000000 ffffffc1f5ce3e90 ffffffc1f5ce3e90
3ea0: 0000000000000000 ffffff8000000000 ffffffc1f5ce3eb0 ffffffc1f5ce3eb0
3ec0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3ee0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3f00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3f20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3f40: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3f60: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3f80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3fa0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
3fc0: 0000000000000000 0000000000000005 0000000000000000 0000000000000000
3fe0: 0000000000000000 0000000000000000 0000000275ce3ff0 0000000275ce3ff8
Call trace:
Exception stack(0xffffffc1f5ce3b30 to 0xffffffc1f5ce3c60)
3b20:                                   dead000000000060 0000008000000000
3b40: ffffffc1f5ce3d00 ffffff80084cb694 0000000000000008 0000000000000e88
3b60: ffffffc1f5ce3bb0 ffffff80080dac68 ffffffc1f5ce3b90 ffffff8008826fe4
3b80: 00000000000001c0 00000000000001c0 ffffffc1f5ce3bb0 ffffff800848dfcc
3ba0: 0000000000020000 ffffff8008b15ae4 ffffffc1f5ce3c00 ffffff800808f000
3bc0: 0000000000000010 ffffff80088377f0 ffffffc1f5ccd590 0000000000000140
3be0: dead000000000100 dead000000000200 0000000000000001 0000000000000000
3c00: 0000000000000000 ffffff8008ce2020 ffffffc1f5cc3338 ffffffc1f5ce0000
3c20: 0000000000000840 0000000000000001 0000000000000000 ffffffffffffffff
3c40: ffffffffffffffff ffffffffffffffff 0000000000000001 0000000000000007
[<ffffff80084cb694>] pl330_irq_handler+0x27c/0x390
[<ffffff80080f09d0>] irq_forced_thread_fn+0x38/0x88
[<ffffff80080f0d70>] irq_thread+0x140/0x200
[<ffffff80080bf4f8>] kthread+0xd8/0xf0
[<ffffff8008083690>] ret_from_fork+0x10/0x40
Code: f2a00838 f9405763 aa1c03e1 aa1503e0 (f9000443)
---[ end trace f50005726d31199c ]---
Kernel panic - not syncing: Fatal exception in interrupt
SMP: stopping secondary CPUs
SMP: failed to stop secondary CPUs 0-1
Kernel Offset: disabled
Memory Limit: none
---[ end Kernel panic - not syncing: Fatal exception in interrupt

To fix this, re-start with the list-head after dropping the lock then
re-takeing it.

Reviewed-by: Frank Mori Hess <fmh6jj@gmail.com>
Tested-by: Frank Mori Hess <fmh6jj@gmail.com>
Signed-off-by: Qi Hou <qi.hou@windriver.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
While testing the deadline scheduler + cgroup setup I hit this
warning.

[  132.612935] ------------[ cut here ]------------
[  132.612951] WARNING: CPU: 5 PID: 0 at kernel/softirq.c:150 __local_bh_enable_ip+0x6b/0x80
[  132.612952] Modules linked in: (a ton of modules...)
[  132.612981] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.7.0-rc2 TinkerBoard#2
[  132.612981] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.2-20150714_191134- 04/01/2014
[  132.612982]  0000000000000086 45c8bb5effdd088b ffff88013fd43da0 ffffffff813d229e
[  132.612984]  0000000000000000 0000000000000000 ffff88013fd43de0 ffffffff810a652b
[  132.612985]  00000096811387b5 0000000000000200 ffff8800bab29d80 ffff880034c54c00
[  132.612986] Call Trace:
[  132.612987]  <IRQ>  [<ffffffff813d229e>] dump_stack+0x63/0x85
[  132.612994]  [<ffffffff810a652b>] __warn+0xcb/0xf0
[  132.612997]  [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170
[  132.612999]  [<ffffffff810a665d>] warn_slowpath_null+0x1d/0x20
[  132.613000]  [<ffffffff810aba5b>] __local_bh_enable_ip+0x6b/0x80
[  132.613008]  [<ffffffff817d6c8a>] _raw_write_unlock_bh+0x1a/0x20
[  132.613010]  [<ffffffff817d6c9e>] _raw_spin_unlock_bh+0xe/0x10
[  132.613015]  [<ffffffff811388ac>] put_css_set+0x5c/0x60
[  132.613016]  [<ffffffff8113dc7f>] cgroup_free+0x7f/0xa0
[  132.613017]  [<ffffffff810a3912>] __put_task_struct+0x42/0x140
[  132.613018]  [<ffffffff810e776a>] dl_task_timer+0xca/0x250
[  132.613027]  [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170
[  132.613030]  [<ffffffff8111371e>] __hrtimer_run_queues+0xee/0x270
[  132.613031]  [<ffffffff81113ec8>] hrtimer_interrupt+0xa8/0x190
[  132.613034]  [<ffffffff81051a58>] local_apic_timer_interrupt+0x38/0x60
[  132.613035]  [<ffffffff817d9b0d>] smp_apic_timer_interrupt+0x3d/0x50
[  132.613037]  [<ffffffff817d7c5c>] apic_timer_interrupt+0x8c/0xa0
[  132.613038]  <EOI>  [<ffffffff81063466>] ? native_safe_halt+0x6/0x10
[  132.613043]  [<ffffffff81037a4e>] default_idle+0x1e/0xd0
[  132.613044]  [<ffffffff810381cf>] arch_cpu_idle+0xf/0x20
[  132.613046]  [<ffffffff810e8fda>] default_idle_call+0x2a/0x40
[  132.613047]  [<ffffffff810e92d7>] cpu_startup_entry+0x2e7/0x340
[  132.613048]  [<ffffffff81050235>] start_secondary+0x155/0x190
[  132.613049] ---[ end trace f91934d162ce9977 ]---

The warn is the spin_(lock|unlock)_bh(&css_set_lock) in the interrupt
context. Converting the spin_lock_bh to spin_lock_irq(save) to avoid
this problem - and other problems of sharing a spinlock with an
interrupt.

Change-Id: I5b5d5c79c3f380ac35f58596fc2cebaf6348eb67
Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: cgroups@vger.kernel.org
Cc: stable@vger.kernel.org # 4.5+
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
commit df30781699f53e4fd4c494c6f7dd16e3d5c21d30 upstream.

For problem determination we need to see whether and why we were successful
or not. This allows deduction of scsi_eh escalation.

Example trace record formatted with zfcpdbf from s390-tools:

Timestamp      : ...
Area           : SCSI
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1
Tag            : schrh_r        SCSI host reset handler result
Request ID     : 0x0000000000000000                     none (invalid)
SCSI ID        : 0xffffffff                             none (invalid)
SCSI LUN       : 0xffffffff                             none (invalid)
SCSI LUN high  : 0xffffffff                             none (invalid)
SCSI result    : 0x00002002     field re-used for midlayer value: SUCCESS
                                or in other cases: 0x2009 == FAST_IO_FAIL
SCSI retries   : 0xff                                   none (invalid)
SCSI allowed   : 0xff                                   none (invalid)
SCSI scribble  : 0xffffffffffffffff                     none (invalid)
SCSI opcode    : ffffffff ffffffff ffffffff ffffffff    none (invalid)
FCP rsp inf cod: 0xff                                   none (invalid)
FCP rsp IU     : 00000000 00000000 00000000 00000000    none (invalid)
                 00000000 00000000

v2.6.35 commit a1dbfdd ("[SCSI] zfcp: Pass return code from
fc_block_scsi_eh to scsi eh") introduced the first return with something
other than the previously hardcoded single SUCCESS return path.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: a1dbfdd ("[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh")
Cc: <stable@vger.kernel.org> TinkerBoard#2.6.38+
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
commit 81979ae63e872ef650a7197f6ce6590059d37172 upstream.

We already have a SCSI trace for the end of abort and scsi_eh TMF. Due to
zfcp_erp_wait() and fc_block_scsi_eh() time can pass between the start of
our eh callback and an actual send/recv of an abort / TMF request.  In order
to see the temporal sequence including any abort / TMF send retries, add a
trace before the above two blocking functions.  This supports problem
determination with scsi_eh and parallel zfcp ERP.

No need to explicitly trace the beginning of our eh callback, since we
typically can send an abort / TMF and see its HBA response (in the worst
case, it's a pseudo response on dismiss all of adapter recovery, e.g. due to
an FSF request timeout [fsrth_1] of the abort / TMF). If we cannot send, we
now get a trace record for the first "abrt_wt" or "[lt]r_wait" which denotes
almost the beginning of the callback.

No need to explicitly trace the wakeup after the above two blocking
functions because the next retry loop causes another trace in any case and
that is sufficient.

Example trace records formatted with zfcpdbf from s390-tools:

Timestamp      : ...
Area           : SCSI
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1
Tag            : abrt_wt        abort, before zfcp_erp_wait()
Request ID     : 0x0000000000000000                     none (invalid)
SCSI ID        : 0x<scsi_id>
SCSI LUN       : 0x<scsi_lun>
SCSI LUN high  : 0x<scsi_lun_high>
SCSI result    : 0x<scsi_result_of_cmd_to_be_aborted>
SCSI retries   : 0x<retries_of_cmd_to_be_aborted>
SCSI allowed   : 0x<allowed_retries_of_cmd_to_be_aborted>
SCSI scribble  : 0x<req_id_of_cmd_to_be_aborted>
SCSI opcode    : <CDB_of_cmd_to_be_aborted>
FCP rsp inf cod: 0x..                                   none (invalid)
FCP rsp IU     : ...                                    none (invalid)

Timestamp      : ...
Area           : SCSI
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1
Tag            : lr_wait        LUN reset, before zfcp_erp_wait()
Request ID     : 0x0000000000000000                     none (invalid)
SCSI ID        : 0x<scsi_id>
SCSI LUN       : 0x<scsi_lun>
SCSI LUN high  : 0x<scsi_lun_high>
SCSI result    : 0x...                                  unrelated
SCSI retries   : 0x..                                   unrelated
SCSI allowed   : 0x..                                   unrelated
SCSI scribble  : 0x...                                  unrelated
SCSI opcode    : ...                                    unrelated
FCP rsp inf cod: 0x..                                   none (invalid)
FCP rsp IU     : ...                                    none (invalid)

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 63caf36 ("[SCSI] zfcp: Improve reliability of SCSI eh handlers in zfcp")
Fixes: af4de36 ("[SCSI] zfcp: Block scsi_eh thread for rport state BLOCKED")
Cc: <stable@vger.kernel.org> TinkerBoard#2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
…ailed

commit 512857a795cbbda5980efa4cdb3c0b6602330408 upstream.

If a SCSI device is deleted during scsi_eh host reset, we cannot get a
reference to the SCSI device anymore since scsi_device_get returns !=0 by
design. Assuming the recovery of adapter and port(s) was successful,
zfcp_erp_strategy_followup_success() attempts to trigger a LUN reset for the
half-gone SCSI device. Unfortunately, it causes the following confusing
trace record which states that zfcp will do a LUN recovery as "ERP need" is
ZFCP_ERP_ACTION_REOPEN_LUN == 1 and equals "ERP want".

Old example trace record formatted with zfcpdbf from s390-tools:

Tag:           : ersfs_3 ERP, trigger, unit reopen, port reopen succeeded
LUN            : 0x<FCP_LUN>
WWPN           : 0x<WWPN>
D_ID           : 0x<N_Port-ID>
Adapter status : 0x5400050b
Port status    : 0x54000001
LUN status     : 0x40000000     ZFCP_STATUS_COMMON_RUNNING
                                but not ZFCP_STATUS_COMMON_UNBLOCKED as it
                                was closed on close part of adapter reopen
ERP want       : 0x01
ERP need       : 0x01           misleading

However, zfcp_erp_setup_act() returns NULL as it cannot get the reference.
Hence, zfcp_erp_action_enqueue() takes an early goto out and _NO_ recovery
actually happens.

We always do want the recovery trigger trace record even if no erp_action
could be enqueued as in this case. For other cases where we did not enqueue
an erp_action, 'need' has always been zero to indicate this. In order to
indicate above goto out, introduce an eyecatcher "flag" to mark the "ERP
need" as 'not needed' but still keep the information which erp_action type,
that zfcp_erp_required_act() had decided upon, is needed.  0xc_ is chosen to
be visibly different from 0x0_ in "ERP want".

New example trace record formatted with zfcpdbf from s390-tools:

Tag:           : ersfs_3 ERP, trigger, unit reopen, port reopen succeeded
LUN            : 0x<FCP_LUN>
WWPN           : 0x<WWPN>
D_ID           : 0x<N_Port-ID>
Adapter status : 0x5400050b
Port status    : 0x54000001
LUN status     : 0x40000000
ERP want       : 0x01
ERP need       : 0xc1           would need LUN ERP, but no action set up
                   ^

Before v2.6.38 commit ae0904f ("[SCSI] zfcp: Redesign of the debug
tracing for recovery actions.") we could detect this case because the
"erp_action" field in the trace was NULL. The rework removed erp_action as
argument and field from the trace.

This patch here is for tracing. A fix to allow LUN recovery in the case at
hand is a topic for a separate patch.

See also commit fdbd1c5 ("[SCSI] zfcp: Allow running unit/LUN shutdown
without acquiring reference") for a similar case and background info.

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: ae0904f ("[SCSI] zfcp: Redesign of the debug tracing for recovery actions.")
Cc: <stable@vger.kernel.org> TinkerBoard#2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
… return

commit 96d9270499471545048ed8a6d7f425a49762283d upstream.

get_device() and its internally used kobject_get() only return NULL if they
get passed NULL as argument. zfcp_get_port_by_wwpn() loops over
adapter->port_list so the iteration variable port is always non-NULL.
Struct device is embedded in struct zfcp_port so &port->dev is always
non-NULL. This is the argument to get_device().  However, if we get an
fc_rport in terminate_rport_io() for which we cannot find a match within
zfcp_get_port_by_wwpn(), the latter can return NULL.  v2.6.30 commit
7093293 ("[SCSI] zfcp: Fix oops when port disappears") introduced an
early return without adding a trace record for this case.  Even if we don't
need recovery in this case, for debugging we should still see that our
callback was invoked originally by scsi_transport_fc.

Example trace record formatted with zfcpdbf from s390-tools:

Timestamp      : ...
Area           : REC
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1
Tag            : sctrpin        SCSI terminate rport I/O, no zfcp port
LUN            : 0xffffffffffffffff                     none (invalid)
WWPN           : 0x<wwpn>               WWPN
D_ID           : 0x<n_port_id>          N_Port-ID
Adapter status : 0x...
Port status    : 0xffffffff             unknown (-1)
LUN status     : 0x00000000                             none (invalid)
Ready count    : 0x...
Running count  : 0x...
ERP want       : 0x03                   ZFCP_ERP_ACTION_REOPEN_PORT_FORCED
ERP need       : 0xc0                   ZFCP_ERP_ACTION_NONE

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Fixes: 7093293 ("[SCSI] zfcp: Fix oops when port disappears")
Cc: <stable@vger.kernel.org> TinkerBoard#2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
…RP_FAILED

commit d70aab55924b44f213fec2b900b095430b33eec6 upstream.

For problem determination we always want to see when we were invoked on the
terminate_rport_io callback whether we perform something or not.

Temporal event sequence of interest with a long fast_io_fail_tmo of 27 sec:

loose remote port

t   workqueue
[s] zfcp_q_<dev>       IRQ                 zfcperp<dev>

=== ================== =================== ============================

  0                    recv RSCN
                       q p.test_link_work
    block rport
     start fast_io_fail_tmo
    send ADISC ELS
  4                    recv ADISC fail
                       block zfcp_port
                                           port forced reopen
                                           send open port
 12                    recv open port fail
                                           q p.gid_pn_work
                                           zfcp_erp_wakeup
                                           (zfcp_erp_wait would return)
    GID_PN fail

Before this point, we got a SCSI trace with tag "sctrpi1" on fast_io_fail,
e.g. with the typical 5 sec setting.

    port.status |= ERP_FAILED

If fast_io_fail_tmo triggers after this point, we missed a SCSI trace.

    workqueue
    fc_dl_<host>
    ==================
 27 fc_timeout_fail_rport_io
    fc_terminate_rport_io
    zfcp_scsi_terminate_rport_io
    zfcp_erp_port_forced_reopen
    _zfcp_erp_port_forced_reopen
     if (port.status & ERP_FAILED)
      return;

Therefore, write a trace before above early return.

Example trace record formatted with zfcpdbf from s390-tools:

Timestamp      : ...
Area           : REC
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1                      ZFCP_DBF_REC_TRIG
Tag            : sctrpi1                SCSI terminate rport I/O
LUN            : 0xffffffffffffffff                     none (invalid)
WWPN           : 0x<wwpn>
D_ID           : 0x<n_port_id>
Adapter status : 0x...
Port status    : 0x...
LUN status     : 0x00000000                             none (invalid)
Ready count    : 0x...
Running count  : 0x...
ERP want       : 0x03                   ZFCP_ERP_ACTION_REOPEN_PORT_FORCED
ERP need       : 0xe0                   ZFCP_ERP_ACTION_FAILED

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Cc: <stable@vger.kernel.org> TinkerBoard#2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
commit 8c3d20aada70042a39c6a6625be037c1472ca610 upstream.

That other commit introduced an inconsistency because it would trace on
ERP_FAILED for all callers of port forced reopen triggers (not just
terminate_rport_io), but it would not trace on ERP_FAILED for all callers of
other ERP triggers such as adapter, port regular, LUN.

Therefore, generalize that other commit. zfcp_erp_action_enqueue() already
had two early outs which re-used the one zfcp_dbf_rec_trig() call.  All ERP
trigger functions finally run through zfcp_erp_action_enqueue().  So move
the special handling for ZFCP_STATUS_COMMON_ERP_FAILED into
zfcp_erp_action_enqueue() and add another early out with new trace marker
for pseudo ERP need in this case. This removes all early returns from all
ERP trigger functions so we always end up at zfcp_dbf_rec_trig().

Example trace record formatted with zfcpdbf from s390-tools:

Timestamp      : ...
Area           : REC
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1                      ZFCP_DBF_REC_TRIG
Tag            : .......
LUN            : 0x...
WWPN           : 0x...
D_ID           : 0x...
Adapter status : 0x...
Port status    : 0x...
LUN status     : 0x...
Ready count    : 0x...
Running count  : 0x...
ERP want       : 0x0.                   ZFCP_ERP_ACTION_REOPEN_...
ERP need       : 0xe0                   ZFCP_ERP_ACTION_FAILED

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Cc: <stable@vger.kernel.org> TinkerBoard#2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
commit 6a76550841d412330bd86aed3238d1888ba70f0e upstream.

Example trace record formatted with zfcpdbf from s390-tools:

Timestamp      : ...
Area           : REC
Subarea        : 00
Level          : 1
Exception      : -
CPU ID         : ..
Caller         : 0x...
Record ID      : 1                      ZFCP_DBF_REC_TRIG
Tag            : .......
LUN            : 0x...
WWPN           : 0x...
D_ID           : 0x...
Adapter status : 0x...
Port status    : 0x...
LUN status     : 0x...
Ready count    : 0x...
Running count  : 0x...
ERP want       : 0x0.                   ZFCP_ERP_ACTION_REOPEN_...
ERP need       : 0xc0                   ZFCP_ERP_ACTION_NONE

Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Cc: <stable@vger.kernel.org> TinkerBoard#2.6.38+
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
commit b63e132b6433a41cf311e8bc382d33fd2b73b505 upstream.

The current MIPS implementation of arch_trigger_cpumask_backtrace() is
broken because it attempts to use synchronous IPIs despite the fact that
it may be run with interrupts disabled.

This means that when arch_trigger_cpumask_backtrace() is invoked, for
example by the RCU CPU stall watchdog, we may:

  - Deadlock due to use of synchronous IPIs with interrupts disabled,
    causing the CPU that's attempting to generate the backtrace output
    to hang itself.

  - Not succeed in generating the desired output from remote CPUs.

  - Produce warnings about this from smp_call_function_many(), for
    example:

    [42760.526910] INFO: rcu_sched detected stalls on CPUs/tasks:
    [42760.535755]  0-...!: (1 GPs behind) idle=ade/140000000000000/0 softirq=526944/526945 fqs=0
    [42760.547874]  1-...!: (0 ticks this GP) idle=e4a/140000000000000/0 softirq=547885/547885 fqs=0
    [42760.559869]  (detected by 2, t=2162 jiffies, g=266689, c=266688, q=33)
    [42760.568927] ------------[ cut here ]------------
    [42760.576146] WARNING: CPU: 2 PID: 1216 at kernel/smp.c:416 smp_call_function_many+0x88/0x20c
    [42760.587839] Modules linked in:
    [42760.593152] CPU: 2 PID: 1216 Comm: sh Not tainted 4.15.4-00373-gee058bb4d0c2 TinkerBoard#2
    [42760.603767] Stack : 8e09bd20 8e09bd20 8e09bd20 fffffff0 00000007 00000006 00000000 8e09bca8
    [42760.616937]         95b2b379 95b2b379 807a0080 00000007 81944518 0000018a 00000032 00000000
    [42760.630095]         00000000 00000030 80000000 00000000 806eca74 00000009 8017e2b8 000001a0
    [42760.643169]         00000000 00000002 00000000 8e09baa4 00000008 808b8008 86d69080 8e09bca0
    [42760.656282]         8e09ad50 805e20aa 00000000 00000000 00000000 8017e2b8 00000009 801070ca
    [42760.669424]         ...
    [42760.673919] Call Trace:
    [42760.678672] [<27fde568>] show_stack+0x70/0xf0
    [42760.685417] [<84751641>] dump_stack+0xaa/0xd0
    [42760.692188] [<699d671c>] __warn+0x80/0x92
    [42760.698549] [<68915d41>] warn_slowpath_null+0x28/0x36
    [42760.705912] [<f7c76c1c>] smp_call_function_many+0x88/0x20c
    [42760.713696] [<6bbdfc2a>] arch_trigger_cpumask_backtrace+0x30/0x4a
    [42760.722216] [<f845bd33>] rcu_dump_cpu_stacks+0x6a/0x98
    [42760.729580] [<796e7629>] rcu_check_callbacks+0x672/0x6ac
    [42760.737476] [<059b3b43>] update_process_times+0x18/0x34
    [42760.744981] [<6eb94941>] tick_sched_handle.isra.5+0x26/0x38
    [42760.752793] [<478d3d70>] tick_sched_timer+0x1c/0x50
    [42760.759882] [<e56ea39f>] __hrtimer_run_queues+0xc6/0x226
    [42760.767418] [<e88bbcae>] hrtimer_interrupt+0x88/0x19a
    [42760.775031] [<6765a19e>] gic_compare_interrupt+0x2e/0x3a
    [42760.782761] [<0558bf5f>] handle_percpu_devid_irq+0x78/0x168
    [42760.790795] [<90c11ba2>] generic_handle_irq+0x1e/0x2c
    [42760.798117] [<1b6d462c>] gic_handle_local_int+0x38/0x86
    [42760.805545] [<b2ada1c7>] gic_irq_dispatch+0xa/0x14
    [42760.812534] [<90c11ba2>] generic_handle_irq+0x1e/0x2c
    [42760.820086] [<c7521934>] do_IRQ+0x16/0x20
    [42760.826274] [<9aef3ce6>] plat_irq_dispatch+0x62/0x94
    [42760.833458] [<6a94b53c>] except_vec_vi_end+0x70/0x78
    [42760.840655] [<22284043>] smp_call_function_many+0x1ba/0x20c
    [42760.848501] [<54022b58>] smp_call_function+0x1e/0x2c
    [42760.855693] [<ab9fc705>] flush_tlb_mm+0x2a/0x98
    [42760.862730] [<0844cdd0>] tlb_flush_mmu+0x1c/0x44
    [42760.869628] [<cb259b74>] arch_tlb_finish_mmu+0x26/0x3e
    [42760.877021] [<1aeaaf74>] tlb_finish_mmu+0x18/0x66
    [42760.883907] [<b3fce717>] exit_mmap+0x76/0xea
    [42760.890428] [<c4c8a2f6>] mmput+0x80/0x11a
    [42760.896632] [<a41a08f4>] do_exit+0x1f4/0x80c
    [42760.903158] [<ee01cef6>] do_group_exit+0x20/0x7e
    [42760.909990] [<13fa8d54>] __wake_up_parent+0x0/0x1e
    [42760.917045] [<46cf89d0>] smp_call_function_many+0x1a2/0x20c
    [42760.924893] [<8c21a93b>] syscall_common+0x14/0x1c
    [42760.931765] ---[ end trace 02aa09da9dc52a60 ]---
    [42760.938342] ------------[ cut here ]------------
    [42760.945311] WARNING: CPU: 2 PID: 1216 at kernel/smp.c:291 smp_call_function_single+0xee/0xf8
    ...

This patch switches MIPS' arch_trigger_cpumask_backtrace() to use async
IPIs & smp_call_function_single_async() in order to resolve this
problem. We ensure use of the pre-allocated call_single_data_t
structures is serialized by maintaining a cpumask indicating that
they're busy, and refusing to attempt to send an IPI when a CPU's bit is
set in this mask. This should only happen if a CPU hasn't responded to a
previous backtrace IPI - ie. if it's hung - and we print a warning to
the console in this case.

I've marked this for stable branches as far back as v4.9, to which it
applies cleanly. Strictly speaking the faulty MIPS implementation can be
traced further back to commit 856839b ("MIPS: Add
arch_trigger_all_cpu_backtrace() function") in v3.19, but kernel
versions v3.19 through v4.8 will require further work to backport due to
the rework performed in commit 9a01c3ed5cdb ("nmi_backtrace: add more
trigger_*_cpu_backtrace() methods").

Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19597/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.9+
Fixes: 856839b ("MIPS: Add arch_trigger_all_cpu_backtrace() function")
Fixes: 9a01c3ed5cdb ("nmi_backtrace: add more trigger_*_cpu_backtrace() methods")
[ Huacai: backported to 4.4: Restruction since generic NMI solution is unavailable ]
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 5, 2018
commit c604cb767049b78b3075497b80ebb8fd530ea2cc upstream.

My recent fix for dns_resolver_preparse() printing very long strings was
incomplete, as shown by syzbot which still managed to hit the
WARN_ONCE() in set_precision() by adding a crafted "dns_resolver" key:

    precision 50001 too large
    WARNING: CPU: 7 PID: 864 at lib/vsprintf.c:2164 vsnprintf+0x48a/0x5a0

The bug this time isn't just a printing bug, but also a logical error
when multiple options ("#"-separated strings) are given in the key
payload.  Specifically, when separating an option string into name and
value, if there is no value then the name is incorrectly considered to
end at the end of the key payload, rather than the end of the current
option.  This bypasses validation of the option length, and also means
that specifying multiple options is broken -- which presumably has gone
unnoticed as there is currently only one valid option anyway.

A similar problem also applied to option values, as the kstrtoul() when
parsing the "dnserror" option will read past the end of the current
option and into the next option.

Fix these bugs by correctly computing the length of the option name and
by copying the option value, null-terminated, into a temporary buffer.

Reproducer for the WARN_ONCE() that syzbot hit:

    perl -e 'print "#A#", "\0" x 50000' | keyctl padd dns_resolver desc @s

Reproducer for "dnserror" option being parsed incorrectly (expected
behavior is to fail when seeing the unknown option "foo", actual
behavior was to read the dnserror value as "1#foo" and fail there):

    perl -e 'print "#dnserror=1#foo\0"' | keyctl padd dns_resolver desc @s

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 4a2d789 ("DNS: If the DNS server returns an error, allow that to be cached [ver TinkerBoard#2]")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 7, 2018
commit 89da619bc18d79bca5304724c11d4ba3b67ce2c6 upstream.

Kernel panic when with high memory pressure, calltrace looks like,

PID: 21439 TASK: ffff881be3afedd0 CPU: 16 COMMAND: "java"
 #0 [ffff881ec7ed7630] machine_kexec at ffffffff81059beb
 TinkerBoard#1 [ffff881ec7ed7690] __crash_kexec at ffffffff81105942
 TinkerBoard#2 [ffff881ec7ed7760] crash_kexec at ffffffff81105a30
 TinkerBoard#3 [ffff881ec7ed7778] oops_end at ffffffff816902c8
 TinkerBoard#4 [ffff881ec7ed77a0] no_context at ffffffff8167ff46
 TinkerBoard#5 [ffff881ec7ed77f0] __bad_area_nosemaphore at ffffffff8167ffdc
 TinkerBoard#6 [ffff881ec7ed7838] __node_set at ffffffff81680300
 TinkerBoard#7 [ffff881ec7ed7860] __do_page_fault at ffffffff8169320f
 TinkerBoard#8 [ffff881ec7ed78c0] do_page_fault at ffffffff816932b5
 TinkerBoard#9 [ffff881ec7ed78f0] page_fault at ffffffff8168f4c8
    [exception RIP: _raw_spin_lock_irqsave+47]
    RIP: ffffffff8168edef RSP: ffff881ec7ed79a8 RFLAGS: 00010046
    RAX: 0000000000000246 RBX: ffffea0019740d00 RCX: ffff881ec7ed7fd8
    RDX: 0000000000020000 RSI: 0000000000000016 RDI: 0000000000000008
    RBP: ffff881ec7ed79a8 R8: 0000000000000246 R9: 000000000001a098
    R10: ffff88107ffda000 R11: 0000000000000000 R12: 0000000000000000
    R13: 0000000000000008 R14: ffff881ec7ed7a80 R15: ffff881be3afedd0
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018

It happens in the pagefault and results in double pagefault
during compacting pages when memory allocation fails.

Analysed the vmcore, the page leads to second pagefault is corrupted
with _mapcount=-256, but private=0.

It's caused by the race between migration and ballooning, and lock
missing in virtballoon_migratepage() of virtio_balloon driver.
This patch fix the bug.

Fixes: e225042 ("virtio_balloon: introduce migration primitives to balloon pages")
Cc: stable@vger.kernel.org
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Huang Chong <huang.chong@zte.com.cn>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 7, 2018
commit 4e1a720d0312fd510699032c7694a362a010170f upstream.

slub debug reported:

[  440.648642] =============================================================================
[  440.648649] BUG kmalloc-1024 (Tainted: G    BU     O   ): Poison overwritten
[  440.648651] -----------------------------------------------------------------------------

[  440.648655] INFO: 0xe70f4bec-0xe70f4bec. First byte 0x6a instead of 0x6b
[  440.648665] INFO: Allocated in sk_prot_alloc+0x6b/0xc6 age=33155 cpu=1 pid=1047
[  440.648671] 	___slab_alloc.constprop.24+0x1fc/0x292
[  440.648675] 	__slab_alloc.isra.18.constprop.23+0x1c/0x25
[  440.648677] 	__kmalloc+0xb6/0x17f
[  440.648680] 	sk_prot_alloc+0x6b/0xc6
[  440.648683] 	sk_alloc+0x1e/0xa1
[  440.648700] 	sco_sock_alloc.constprop.6+0x26/0xaf [bluetooth]
[  440.648716] 	sco_connect_cfm+0x166/0x281 [bluetooth]
[  440.648731] 	hci_conn_request_evt.isra.53+0x258/0x281 [bluetooth]
[  440.648746] 	hci_event_packet+0x28b/0x2326 [bluetooth]
[  440.648759] 	hci_rx_work+0x161/0x291 [bluetooth]
[  440.648764] 	process_one_work+0x163/0x2b2
[  440.648767] 	worker_thread+0x1a9/0x25c
[  440.648770] 	kthread+0xf8/0xfd
[  440.648774] 	ret_from_fork+0x2e/0x38
[  440.648779] INFO: Freed in __sk_destruct+0xd3/0xdf age=3815 cpu=1 pid=1047
[  440.648782] 	__slab_free+0x4b/0x27a
[  440.648784] 	kfree+0x12e/0x155
[  440.648787] 	__sk_destruct+0xd3/0xdf
[  440.648790] 	sk_destruct+0x27/0x29
[  440.648793] 	__sk_free+0x75/0x91
[  440.648795] 	sk_free+0x1c/0x1e
[  440.648810] 	sco_sock_kill+0x5a/0x5f [bluetooth]
[  440.648825] 	sco_conn_del+0x8e/0xba [bluetooth]
[  440.648840] 	sco_disconn_cfm+0x3a/0x41 [bluetooth]
[  440.648855] 	hci_event_packet+0x45e/0x2326 [bluetooth]
[  440.648868] 	hci_rx_work+0x161/0x291 [bluetooth]
[  440.648872] 	process_one_work+0x163/0x2b2
[  440.648875] 	worker_thread+0x1a9/0x25c
[  440.648877] 	kthread+0xf8/0xfd
[  440.648880] 	ret_from_fork+0x2e/0x38
[  440.648884] INFO: Slab 0xf4718580 objects=27 used=27 fp=0x  (null) flags=0x40008100
[  440.648886] INFO: Object 0xe70f4b88 @offset=19336 fp=0xe70f54f8

When KASAN was enabled, it reported:

[  210.096613] ==================================================================
[  210.096634] BUG: KASAN: use-after-free in ex_handler_refcount+0x5b/0x127
[  210.096641] Write of size 4 at addr ffff880107e17160 by task kworker/u9:1/2040

[  210.096651] CPU: 1 PID: 2040 Comm: kworker/u9:1 Tainted: G     U     O    4.14.47-20180606+ TinkerBoard#2
[  210.096654] Hardware name: , BIOS 2017.01-00087-g43e04de 08/30/2017
[  210.096693] Workqueue: hci0 hci_rx_work [bluetooth]
[  210.096698] Call Trace:
[  210.096711]  dump_stack+0x46/0x59
[  210.096722]  print_address_description+0x6b/0x23b
[  210.096729]  ? ex_handler_refcount+0x5b/0x127
[  210.096736]  kasan_report+0x220/0x246
[  210.096744]  ex_handler_refcount+0x5b/0x127
[  210.096751]  ? ex_handler_clear_fs+0x85/0x85
[  210.096757]  fixup_exception+0x8c/0x96
[  210.096766]  do_trap+0x66/0x2c1
[  210.096773]  do_error_trap+0x152/0x180
[  210.096781]  ? fixup_bug+0x78/0x78
[  210.096817]  ? hci_debugfs_create_conn+0x244/0x26a [bluetooth]
[  210.096824]  ? __schedule+0x113b/0x1453
[  210.096830]  ? sysctl_net_exit+0xe/0xe
[  210.096837]  ? __wake_up_common+0x343/0x343
[  210.096843]  ? insert_work+0x107/0x163
[  210.096850]  invalid_op+0x1b/0x40
[  210.096888] RIP: 0010:hci_debugfs_create_conn+0x244/0x26a [bluetooth]
[  210.096892] RSP: 0018:ffff880094a0f970 EFLAGS: 00010296
[  210.096898] RAX: 0000000000000000 RBX: ffff880107e170e8 RCX: ffff880107e17160
[  210.096902] RDX: 000000000000002f RSI: ffff88013b80ed40 RDI: ffffffffa058b940
[  210.096906] RBP: ffff88011b2b0578 R08: 00000000852f0ec9 R09: ffffffff81cfcf9b
[  210.096909] R10: 00000000d21bdad7 R11: 0000000000000001 R12: ffff8800967b0488
[  210.096913] R13: ffff880107e17168 R14: 0000000000000068 R15: ffff8800949c0008
[  210.096920]  ? __sk_destruct+0x2c6/0x2d4
[  210.096959]  hci_event_packet+0xff5/0x7de2 [bluetooth]
[  210.096969]  ? __local_bh_enable_ip+0x43/0x5b
[  210.097004]  ? l2cap_sock_recv_cb+0x158/0x166 [bluetooth]
[  210.097039]  ? hci_le_meta_evt+0x2bb3/0x2bb3 [bluetooth]
[  210.097075]  ? l2cap_ertm_init+0x94e/0x94e [bluetooth]
[  210.097093]  ? xhci_urb_enqueue+0xbd8/0xcf5 [xhci_hcd]
[  210.097102]  ? __accumulate_pelt_segments+0x24/0x33
[  210.097109]  ? __accumulate_pelt_segments+0x24/0x33
[  210.097115]  ? __update_load_avg_se.isra.2+0x217/0x3a4
[  210.097122]  ? set_next_entity+0x7c3/0x12cd
[  210.097128]  ? pick_next_entity+0x25e/0x26c
[  210.097135]  ? pick_next_task_fair+0x2ca/0xc1a
[  210.097141]  ? switch_mm_irqs_off+0x346/0xb4f
[  210.097147]  ? __switch_to+0x769/0xbc4
[  210.097153]  ? compat_start_thread+0x66/0x66
[  210.097188]  ? hci_conn_check_link_mode+0x1cd/0x1cd [bluetooth]
[  210.097195]  ? finish_task_switch+0x392/0x431
[  210.097228]  ? hci_rx_work+0x154/0x487 [bluetooth]
[  210.097260]  hci_rx_work+0x154/0x487 [bluetooth]
[  210.097269]  process_one_work+0x579/0x9e9
[  210.097277]  worker_thread+0x68f/0x804
[  210.097285]  kthread+0x31c/0x32b
[  210.097292]  ? rescuer_thread+0x70c/0x70c
[  210.097299]  ? kthread_create_on_node+0xa3/0xa3
[  210.097306]  ret_from_fork+0x35/0x40

[  210.097314] Allocated by task 2040:
[  210.097323]  kasan_kmalloc.part.1+0x51/0xc7
[  210.097328]  __kmalloc+0x17f/0x1b6
[  210.097335]  sk_prot_alloc+0xf2/0x1a3
[  210.097340]  sk_alloc+0x22/0x297
[  210.097375]  sco_sock_alloc.constprop.7+0x23/0x202 [bluetooth]
[  210.097410]  sco_connect_cfm+0x2d0/0x566 [bluetooth]
[  210.097443]  hci_conn_request_evt.isra.53+0x6d3/0x762 [bluetooth]
[  210.097476]  hci_event_packet+0x85e/0x7de2 [bluetooth]
[  210.097507]  hci_rx_work+0x154/0x487 [bluetooth]
[  210.097512]  process_one_work+0x579/0x9e9
[  210.097517]  worker_thread+0x68f/0x804
[  210.097523]  kthread+0x31c/0x32b
[  210.097529]  ret_from_fork+0x35/0x40

[  210.097533] Freed by task 2040:
[  210.097539]  kasan_slab_free+0xb3/0x15e
[  210.097544]  kfree+0x103/0x1a9
[  210.097549]  __sk_destruct+0x2c6/0x2d4
[  210.097584]  sco_conn_del.isra.1+0xba/0x10e [bluetooth]
[  210.097617]  hci_event_packet+0xff5/0x7de2 [bluetooth]
[  210.097648]  hci_rx_work+0x154/0x487 [bluetooth]
[  210.097653]  process_one_work+0x579/0x9e9
[  210.097658]  worker_thread+0x68f/0x804
[  210.097663]  kthread+0x31c/0x32b
[  210.097670]  ret_from_fork+0x35/0x40

[  210.097676] The buggy address belongs to the object at ffff880107e170e8
 which belongs to the cache kmalloc-1024 of size 1024
[  210.097681] The buggy address is located 120 bytes inside of
 1024-byte region [ffff880107e170e8, ffff880107e174e8)
[  210.097683] The buggy address belongs to the page:
[  210.097689] page:ffffea00041f8400 count:1 mapcount:0 mapping:          (null) index:0xffff880107e15b68 compound_mapcount: 0
[  210.110194] flags: 0x8000000000008100(slab|head)
[  210.115441] raw: 8000000000008100 0000000000000000 ffff880107e15b68 0000000100170016
[  210.115448] raw: ffffea0004a47620 ffffea0004b48e20 ffff88013b80ed40 0000000000000000
[  210.115451] page dumped because: kasan: bad access detected

[  210.115454] Memory state around the buggy address:
[  210.115460]  ffff880107e17000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  210.115465]  ffff880107e17080: fc fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb
[  210.115469] >ffff880107e17100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  210.115472]                                                        ^
[  210.115477]  ffff880107e17180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  210.115481]  ffff880107e17200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  210.115483] ==================================================================

And finally when BT_DBG() and ftrace was enabled it showed:

       <...>-14979 [001] ....   186.104191: sco_sock_kill <-sco_sock_close
       <...>-14979 [001] ....   186.104191: sco_sock_kill <-sco_sock_release
       <...>-14979 [001] ....   186.104192: sco_sock_kill: sk ef0497a0 state 9
       <...>-14979 [001] ....   186.104193: bt_sock_unlink <-sco_sock_kill
kworker/u9:2-792   [001] ....   186.104246: sco_sock_kill <-sco_conn_del
kworker/u9:2-792   [001] ....   186.104248: sco_sock_kill: sk ef0497a0 state 9
kworker/u9:2-792   [001] ....   186.104249: bt_sock_unlink <-sco_sock_kill
kworker/u9:2-792   [001] ....   186.104250: sco_sock_destruct <-__sk_destruct
kworker/u9:2-792   [001] ....   186.104250: sco_sock_destruct: sk ef0497a0
kworker/u9:2-792   [001] ....   186.104860: hci_conn_del <-hci_event_packet
kworker/u9:2-792   [001] ....   186.104864: hci_conn_del: hci0 hcon ef0484c0 handle 266

Only in the failed case, sco_sock_kill() gets called with the same sock
pointer two times. Add a check for SOCK_DEAD to avoid continue killing
a socket which has already been killed.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 7, 2018
commit ccd5b3235180eef3cfec337df1c8554ab151b5cc upstream.

The following commit:

  39a0526fb3f7 ("x86/mm: Factor out LDT init from context init")

renamed init_new_context() to init_new_context_ldt() and added a new
init_new_context() which calls init_new_context_ldt().  However, the
error code of init_new_context_ldt() was ignored.  Consequently, if a
memory allocation in alloc_ldt_struct() failed during a fork(), the
->context.ldt of the new task remained the same as that of the old task
(due to the memcpy() in dup_mm()).  ldt_struct's are not intended to be
shared, so a use-after-free occurred after one task exited.

Fix the bug by making init_new_context() pass through the error code of
init_new_context_ldt().

This bug was found by syzkaller, which encountered the following splat:

    BUG: KASAN: use-after-free in free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116
    Read of size 4 at addr ffff88006d2cb7c8 by task kworker/u9:0/3710

    CPU: 1 PID: 3710 Comm: kworker/u9:0 Not tainted 4.13.0-rc4-next-20170811 TinkerBoard#2
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
    Call Trace:
     __dump_stack lib/dump_stack.c:16 [inline]
     dump_stack+0x194/0x257 lib/dump_stack.c:52
     print_address_description+0x73/0x250 mm/kasan/report.c:252
     kasan_report_error mm/kasan/report.c:351 [inline]
     kasan_report+0x24e/0x340 mm/kasan/report.c:409
     __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429
     free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116
     free_ldt_struct arch/x86/kernel/ldt.c:173 [inline]
     destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171
     destroy_context arch/x86/include/asm/mmu_context.h:157 [inline]
     __mmdrop+0xe9/0x530 kernel/fork.c:889
     mmdrop include/linux/sched/mm.h:42 [inline]
     exec_mmap fs/exec.c:1061 [inline]
     flush_old_exec+0x173c/0x1ff0 fs/exec.c:1291
     load_elf_binary+0x81f/0x4ba0 fs/binfmt_elf.c:855
     search_binary_handler+0x142/0x6b0 fs/exec.c:1652
     exec_binprm fs/exec.c:1694 [inline]
     do_execveat_common.isra.33+0x1746/0x22e0 fs/exec.c:1816
     do_execve+0x31/0x40 fs/exec.c:1860
     call_usermodehelper_exec_async+0x457/0x8f0 kernel/umh.c:100
     ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431

    Allocated by task 3700:
     save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
     save_stack+0x43/0xd0 mm/kasan/kasan.c:447
     set_track mm/kasan/kasan.c:459 [inline]
     kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
     kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627
     kmalloc include/linux/slab.h:493 [inline]
     alloc_ldt_struct+0x52/0x140 arch/x86/kernel/ldt.c:67
     write_ldt+0x7b7/0xab0 arch/x86/kernel/ldt.c:277
     sys_modify_ldt+0x1ef/0x240 arch/x86/kernel/ldt.c:307
     entry_SYSCALL_64_fastpath+0x1f/0xbe

    Freed by task 3700:
     save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
     save_stack+0x43/0xd0 mm/kasan/kasan.c:447
     set_track mm/kasan/kasan.c:459 [inline]
     kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
     __cache_free mm/slab.c:3503 [inline]
     kfree+0xca/0x250 mm/slab.c:3820
     free_ldt_struct.part.2+0xdd/0x150 arch/x86/kernel/ldt.c:121
     free_ldt_struct arch/x86/kernel/ldt.c:173 [inline]
     destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171
     destroy_context arch/x86/include/asm/mmu_context.h:157 [inline]
     __mmdrop+0xe9/0x530 kernel/fork.c:889
     mmdrop include/linux/sched/mm.h:42 [inline]
     __mmput kernel/fork.c:916 [inline]
     mmput+0x541/0x6e0 kernel/fork.c:927
     copy_process.part.36+0x22e1/0x4af0 kernel/fork.c:1931
     copy_process kernel/fork.c:1546 [inline]
     _do_fork+0x1ef/0xfb0 kernel/fork.c:2025
     SYSC_clone kernel/fork.c:2135 [inline]
     SyS_clone+0x37/0x50 kernel/fork.c:2129
     do_syscall_64+0x26c/0x8c0 arch/x86/entry/common.c:287
     return_from_SYSCALL_64+0x0/0x7a

Here is a C reproducer:

    #include <asm/ldt.h>
    #include <pthread.h>
    #include <signal.h>
    #include <stdlib.h>
    #include <sys/syscall.h>
    #include <sys/wait.h>
    #include <unistd.h>

    static void *fork_thread(void *_arg)
    {
        fork();
    }

    int main(void)
    {
        struct user_desc desc = { .entry_number = 8191 };

        syscall(__NR_modify_ldt, 1, &desc, sizeof(desc));

        for (;;) {
            if (fork() == 0) {
                pthread_t t;

                srand(getpid());
                pthread_create(&t, NULL, fork_thread, NULL);
                usleep(rand() % 10000);
                syscall(__NR_exit_group, 0);
            }
            wait(NULL);
        }
    }

Note: the reproducer takes advantage of the fact that alloc_ldt_struct()
may use vmalloc() to allocate a large ->entries array, and after
commit:

  5d17a73a2ebe ("vmalloc: back off when the current task is killed")

it is possible for userspace to fail a task's vmalloc() by
sending a fatal signal, e.g. via exit_group().  It would be more
difficult to reproduce this bug on kernels without that commit.

This bug only affected kernels with CONFIG_MODIFY_LDT_SYSCALL=y.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: <stable@vger.kernel.org> [v4.6+]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Fixes: 39a0526fb3f7 ("x86/mm: Factor out LDT init from context init")
Link: http://lkml.kernel.org/r/20170824175029.76040-1-ebiggers3@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 7, 2018
commit b45d71fb89ab8adfe727b9d0ee188ed58582a647 upstream.

Directories and inodes don't necessarily need to be in the same lockdep
class.  For ex, hugetlbfs splits them out too to prevent false positives
in lockdep.  Annotate correctly after new inode creation.  If its a
directory inode, it will be put into a different class.

This should fix a lockdep splat reported by syzbot:

> ======================================================
> WARNING: possible circular locking dependency detected
> 4.18.0-rc8-next-20180810+ TinkerBoard#36 Not tainted
> ------------------------------------------------------
> syz-executor900/4483 is trying to acquire lock:
> 00000000d2bfc8fe (&sb->s_type->i_mutex_key#9){++++}, at: inode_lock
> include/linux/fs.h:765 [inline]
> 00000000d2bfc8fe (&sb->s_type->i_mutex_key#9){++++}, at:
> shmem_fallocate+0x18b/0x12e0 mm/shmem.c:2602
>
> but task is already holding lock:
> 0000000025208078 (ashmem_mutex){+.+.}, at: ashmem_shrink_scan+0xb4/0x630
> drivers/staging/android/ashmem.c:448
>
> which lock already depends on the new lock.
>
> -> TinkerBoard#2 (ashmem_mutex){+.+.}:
>        __mutex_lock_common kernel/locking/mutex.c:925 [inline]
>        __mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073
>        mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
>        ashmem_mmap+0x55/0x520 drivers/staging/android/ashmem.c:361
>        call_mmap include/linux/fs.h:1844 [inline]
>        mmap_region+0xf27/0x1c50 mm/mmap.c:1762
>        do_mmap+0xa10/0x1220 mm/mmap.c:1535
>        do_mmap_pgoff include/linux/mm.h:2298 [inline]
>        vm_mmap_pgoff+0x213/0x2c0 mm/util.c:357
>        ksys_mmap_pgoff+0x4da/0x660 mm/mmap.c:1585
>        __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
>        __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline]
>        __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> -> TinkerBoard#1 (&mm->mmap_sem){++++}:
>        __might_fault+0x155/0x1e0 mm/memory.c:4568
>        _copy_to_user+0x30/0x110 lib/usercopy.c:25
>        copy_to_user include/linux/uaccess.h:155 [inline]
>        filldir+0x1ea/0x3a0 fs/readdir.c:196
>        dir_emit_dot include/linux/fs.h:3464 [inline]
>        dir_emit_dots include/linux/fs.h:3475 [inline]
>        dcache_readdir+0x13a/0x620 fs/libfs.c:193
>        iterate_dir+0x48b/0x5d0 fs/readdir.c:51
>        __do_sys_getdents fs/readdir.c:231 [inline]
>        __se_sys_getdents fs/readdir.c:212 [inline]
>        __x64_sys_getdents+0x29f/0x510 fs/readdir.c:212
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> -> #0 (&sb->s_type->i_mutex_key#9){++++}:
>        lock_acquire+0x1e4/0x540 kernel/locking/lockdep.c:3924
>        down_write+0x8f/0x130 kernel/locking/rwsem.c:70
>        inode_lock include/linux/fs.h:765 [inline]
>        shmem_fallocate+0x18b/0x12e0 mm/shmem.c:2602
>        ashmem_shrink_scan+0x236/0x630 drivers/staging/android/ashmem.c:455
>        ashmem_ioctl+0x3ae/0x13a0 drivers/staging/android/ashmem.c:797
>        vfs_ioctl fs/ioctl.c:46 [inline]
>        file_ioctl fs/ioctl.c:501 [inline]
>        do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
>        ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
>        __do_sys_ioctl fs/ioctl.c:709 [inline]
>        __se_sys_ioctl fs/ioctl.c:707 [inline]
>        __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
>        do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>        entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> other info that might help us debug this:
>
> Chain exists of:
>   &sb->s_type->i_mutex_key#9 --> &mm->mmap_sem --> ashmem_mutex
>
>  Possible unsafe locking scenario:
>
>        CPU0                    CPU1
>        ----                    ----
>   lock(ashmem_mutex);
>                                lock(&mm->mmap_sem);
>                                lock(ashmem_mutex);
>   lock(&sb->s_type->i_mutex_key#9);
>
>  *** DEADLOCK ***
>
> 1 lock held by syz-executor900/4483:
>  #0: 0000000025208078 (ashmem_mutex){+.+.}, at:
> ashmem_shrink_scan+0xb4/0x630 drivers/staging/android/ashmem.c:448

Link: http://lkml.kernel.org/r/20180821231835.166639-1-joel@joelfernandes.org
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Suggested-by: NeilBrown <neilb@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 7, 2018
commit 1816494330a83f2a064499d8ed2797045641f92c upstream.

This change has the following effects, in order of descreasing importance:

1) Prevent a stack buffer overflow

2) Do not append an unnecessary NULL to an anyway binary buffer, which
   is writing one byte past client_digest when caller is:
   chap_string_to_hex(client_digest, chap_r, strlen(chap_r));

The latter was found by KASAN (see below) when input value hes expected size
(32 hex chars), and further analysis revealed a stack buffer overflow can
happen when network-received value is longer, allowing an unauthenticated
remote attacker to smash up to 17 bytes after destination buffer (16 bytes
attacker-controlled and one null).  As switching to hex2bin requires
specifying destination buffer length, and does not internally append any null,
it solves both issues.

This addresses CVE-2018-14633.

Beyond this:

- Validate received value length and check hex2bin accepted the input, to log
  this rejection reason instead of just failing authentication.

- Only log received CHAP_R and CHAP_C values once they passed sanity checks.

==================================================================
BUG: KASAN: stack-out-of-bounds in chap_string_to_hex+0x32/0x60 [iscsi_target_mod]
Write of size 1 at addr ffff8801090ef7c8 by task kworker/0:0/1021

CPU: 0 PID: 1021 Comm: kworker/0:0 Tainted: G           O      4.17.8kasan.sess.connops+ TinkerBoard#2
Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 05/19/2014
Workqueue: events iscsi_target_do_login_rx [iscsi_target_mod]
Call Trace:
 dump_stack+0x71/0xac
 print_address_description+0x65/0x22e
 ? chap_string_to_hex+0x32/0x60 [iscsi_target_mod]
 kasan_report.cold.6+0x241/0x2fd
 chap_string_to_hex+0x32/0x60 [iscsi_target_mod]
 chap_server_compute_md5.isra.2+0x2cb/0x860 [iscsi_target_mod]
 ? chap_binaryhex_to_asciihex.constprop.5+0x50/0x50 [iscsi_target_mod]
 ? ftrace_caller_op_ptr+0xe/0xe
 ? __orc_find+0x6f/0xc0
 ? unwind_next_frame+0x231/0x850
 ? kthread+0x1a0/0x1c0
 ? ret_from_fork+0x35/0x40
 ? ret_from_fork+0x35/0x40
 ? iscsi_target_do_login_rx+0x3bc/0x4c0 [iscsi_target_mod]
 ? deref_stack_reg+0xd0/0xd0
 ? iscsi_target_do_login_rx+0x3bc/0x4c0 [iscsi_target_mod]
 ? is_module_text_address+0xa/0x11
 ? kernel_text_address+0x4c/0x110
 ? __save_stack_trace+0x82/0x100
 ? ret_from_fork+0x35/0x40
 ? save_stack+0x8c/0xb0
 ? 0xffffffffc1660000
 ? iscsi_target_do_login+0x155/0x8d0 [iscsi_target_mod]
 ? iscsi_target_do_login_rx+0x3bc/0x4c0 [iscsi_target_mod]
 ? process_one_work+0x35c/0x640
 ? worker_thread+0x66/0x5d0
 ? kthread+0x1a0/0x1c0
 ? ret_from_fork+0x35/0x40
 ? iscsi_update_param_value+0x80/0x80 [iscsi_target_mod]
 ? iscsit_release_cmd+0x170/0x170 [iscsi_target_mod]
 chap_main_loop+0x172/0x570 [iscsi_target_mod]
 ? chap_server_compute_md5.isra.2+0x860/0x860 [iscsi_target_mod]
 ? rx_data+0xd6/0x120 [iscsi_target_mod]
 ? iscsit_print_session_params+0xd0/0xd0 [iscsi_target_mod]
 ? cyc2ns_read_begin.part.2+0x90/0x90
 ? _raw_spin_lock_irqsave+0x25/0x50
 ? memcmp+0x45/0x70
 iscsi_target_do_login+0x875/0x8d0 [iscsi_target_mod]
 ? iscsi_target_check_first_request.isra.5+0x1a0/0x1a0 [iscsi_target_mod]
 ? del_timer+0xe0/0xe0
 ? memset+0x1f/0x40
 ? flush_sigqueue+0x29/0xd0
 iscsi_target_do_login_rx+0x3bc/0x4c0 [iscsi_target_mod]
 ? iscsi_target_nego_release+0x80/0x80 [iscsi_target_mod]
 ? iscsi_target_restore_sock_callbacks+0x130/0x130 [iscsi_target_mod]
 process_one_work+0x35c/0x640
 worker_thread+0x66/0x5d0
 ? flush_rcu_work+0x40/0x40
 kthread+0x1a0/0x1c0
 ? kthread_bind+0x30/0x30
 ret_from_fork+0x35/0x40

The buggy address belongs to the page:
page:ffffea0004243bc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x17fffc000000000()
raw: 017fffc000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: ffffea0004243c20 ffffea0004243ba0 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801090ef680: f2 f2 f2 f2 f2 f2 f2 01 f2 f2 f2 f2 f2 f2 f2 00
 ffff8801090ef700: f2 f2 f2 f2 f2 f2 f2 00 02 f2 f2 f2 f2 f2 f2 00
>ffff8801090ef780: 00 f2 f2 f2 f2 f2 f2 00 00 f2 f2 f2 f2 f2 f2 00
                                              ^
 ffff8801090ef800: 00 f2 f2 f2 f2 f2 f2 00 00 00 00 02 f2 f2 f2 f2
 ffff8801090ef880: f2 f2 f2 00 00 00 00 00 00 00 00 f2 f2 f2 f2 00
==================================================================

Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 7, 2018
commit 234b69e3e089d850a98e7b3145bd00e9b52b1111 upstream.

While reading block, it is possible that io error return due to underlying
storage issue, in this case, BH_NeedsValidate was left in the buffer head.
Then when reading the very block next time, if it was already linked into
journal, that will trigger the following panic.

[203748.702517] kernel BUG at fs/ocfs2/buffer_head_io.c:342!
[203748.702533] invalid opcode: 0000 [TinkerBoard#1] SMP
[203748.702561] Modules linked in: ocfs2 ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs sunrpc dm_switch dm_queue_length dm_multipath bonding be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb4i iw_cxgb4 cxgb4 cxgb3i libcxgbi iw_cxgb3 cxgb3 mdio ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr ipv6 iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ipmi_devintf iTCO_wdt iTCO_vendor_support dcdbas ipmi_ssif i2c_core ipmi_si ipmi_msghandler acpi_pad pcspkr sb_edac edac_core lpc_ich mfd_core shpchp sg tg3 ptp pps_core ext4 jbd2 mbcache2 sr_mod cdrom sd_mod ahci libahci megaraid_sas wmi dm_mirror dm_region_hash dm_log dm_mod
[203748.703024] CPU: 7 PID: 38369 Comm: touch Not tainted 4.1.12-124.18.6.el6uek.x86_64 TinkerBoard#2
[203748.703045] Hardware name: Dell Inc. PowerEdge R620/0PXXHP, BIOS 2.5.2 01/28/2015
[203748.703067] task: ffff880768139c00 ti: ffff88006ff48000 task.ti: ffff88006ff48000
[203748.703088] RIP: 0010:[<ffffffffa05e9f09>]  [<ffffffffa05e9f09>] ocfs2_read_blocks+0x669/0x7f0 [ocfs2]
[203748.703130] RSP: 0018:ffff88006ff4b818  EFLAGS: 00010206
[203748.703389] RAX: 0000000008620029 RBX: ffff88006ff4b910 RCX: 0000000000000000
[203748.703885] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00000000023079fe
[203748.704382] RBP: ffff88006ff4b8d8 R08: 0000000000000000 R09: ffff8807578c25b0
[203748.704877] R10: 000000000f637376 R11: 000000003030322e R12: 0000000000000000
[203748.705373] R13: ffff88006ff4b910 R14: ffff880732fe38f0 R15: 0000000000000000
[203748.705871] FS:  00007f401992c700(0000) GS:ffff880bfebc0000(0000) knlGS:0000000000000000
[203748.706370] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[203748.706627] CR2: 00007f4019252440 CR3: 00000000a621e000 CR4: 0000000000060670
[203748.707124] Stack:
[203748.707371]  ffff88006ff4b828 ffffffffa0609f52 ffff88006ff4b838 0000000000000001
[203748.707885]  0000000000000000 0000000000000000 ffff880bf67c3800 ffffffffa05eca00
[203748.708399]  00000000023079ff ffffffff81c58b80 0000000000000000 0000000000000000
[203748.708915] Call Trace:
[203748.709175]  [<ffffffffa0609f52>] ? ocfs2_inode_cache_io_unlock+0x12/0x20 [ocfs2]
[203748.709680]  [<ffffffffa05eca00>] ? ocfs2_empty_dir_filldir+0x80/0x80 [ocfs2]
[203748.710185]  [<ffffffffa05ec0cb>] ocfs2_read_dir_block_direct+0x3b/0x200 [ocfs2]
[203748.710691]  [<ffffffffa05f0fbf>] ocfs2_prepare_dx_dir_for_insert.isra.57+0x19f/0xf60 [ocfs2]
[203748.711204]  [<ffffffffa065660f>] ? ocfs2_metadata_cache_io_unlock+0x1f/0x30 [ocfs2]
[203748.711716]  [<ffffffffa05f4f3a>] ocfs2_prepare_dir_for_insert+0x13a/0x890 [ocfs2]
[203748.712227]  [<ffffffffa05f442e>] ? ocfs2_check_dir_for_entry+0x8e/0x140 [ocfs2]
[203748.712737]  [<ffffffffa061b2f2>] ocfs2_mknod+0x4b2/0x1370 [ocfs2]
[203748.713003]  [<ffffffffa061c385>] ocfs2_create+0x65/0x170 [ocfs2]
[203748.713263]  [<ffffffff8121714b>] vfs_create+0xdb/0x150
[203748.713518]  [<ffffffff8121b225>] do_last+0x815/0x1210
[203748.713772]  [<ffffffff812192e9>] ? path_init+0xb9/0x450
[203748.714123]  [<ffffffff8121bca0>] path_openat+0x80/0x600
[203748.714378]  [<ffffffff811bcd45>] ? handle_pte_fault+0xd15/0x1620
[203748.714634]  [<ffffffff8121d7ba>] do_filp_open+0x3a/0xb0
[203748.714888]  [<ffffffff8122a767>] ? __alloc_fd+0xa7/0x130
[203748.715143]  [<ffffffff81209ffc>] do_sys_open+0x12c/0x220
[203748.715403]  [<ffffffff81026ddb>] ? syscall_trace_enter_phase1+0x11b/0x180
[203748.715668]  [<ffffffff816f0c9f>] ? system_call_after_swapgs+0xe9/0x190
[203748.715928]  [<ffffffff8120a10e>] SyS_open+0x1e/0x20
[203748.716184]  [<ffffffff816f0d5e>] system_call_fastpath+0x18/0xd7
[203748.716440] Code: 00 00 48 8b 7b 08 48 83 c3 10 45 89 f8 44 89 e1 44 89 f2 4c 89 ee e8 07 06 11 e1 48 8b 03 48 85 c0 75 df 8b 5d c8 e9 4d fa ff ff <0f> 0b 48 8b 7d a0 e8 dc c6 06 00 48 b8 00 00 00 00 00 00 00 10
[203748.717505] RIP  [<ffffffffa05e9f09>] ocfs2_read_blocks+0x669/0x7f0 [ocfs2]
[203748.717775]  RSP <ffff88006ff4b818>

Joesph ever reported a similar panic.
Link: https://oss.oracle.com/pipermail/ocfs2-devel/2013-May/008931.html

Link: http://lkml.kernel.org/r/20180912063207.29484-1-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Changwei Ge <ge.changwei@h3c.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 7, 2018
commit b63e132b6433a41cf311e8bc382d33fd2b73b505 upstream.

The current MIPS implementation of arch_trigger_cpumask_backtrace() is
broken because it attempts to use synchronous IPIs despite the fact that
it may be run with interrupts disabled.

This means that when arch_trigger_cpumask_backtrace() is invoked, for
example by the RCU CPU stall watchdog, we may:

  - Deadlock due to use of synchronous IPIs with interrupts disabled,
    causing the CPU that's attempting to generate the backtrace output
    to hang itself.

  - Not succeed in generating the desired output from remote CPUs.

  - Produce warnings about this from smp_call_function_many(), for
    example:

    [42760.526910] INFO: rcu_sched detected stalls on CPUs/tasks:
    [42760.535755]  0-...!: (1 GPs behind) idle=ade/140000000000000/0 softirq=526944/526945 fqs=0
    [42760.547874]  1-...!: (0 ticks this GP) idle=e4a/140000000000000/0 softirq=547885/547885 fqs=0
    [42760.559869]  (detected by 2, t=2162 jiffies, g=266689, c=266688, q=33)
    [42760.568927] ------------[ cut here ]------------
    [42760.576146] WARNING: CPU: 2 PID: 1216 at kernel/smp.c:416 smp_call_function_many+0x88/0x20c
    [42760.587839] Modules linked in:
    [42760.593152] CPU: 2 PID: 1216 Comm: sh Not tainted 4.15.4-00373-gee058bb4d0c2 TinkerBoard#2
    [42760.603767] Stack : 8e09bd20 8e09bd20 8e09bd20 fffffff0 00000007 00000006 00000000 8e09bca8
    [42760.616937]         95b2b379 95b2b379 807a0080 00000007 81944518 0000018a 00000032 00000000
    [42760.630095]         00000000 00000030 80000000 00000000 806eca74 00000009 8017e2b8 000001a0
    [42760.643169]         00000000 00000002 00000000 8e09baa4 00000008 808b8008 86d69080 8e09bca0
    [42760.656282]         8e09ad50 805e20aa 00000000 00000000 00000000 8017e2b8 00000009 801070ca
    [42760.669424]         ...
    [42760.673919] Call Trace:
    [42760.678672] [<27fde568>] show_stack+0x70/0xf0
    [42760.685417] [<84751641>] dump_stack+0xaa/0xd0
    [42760.692188] [<699d671c>] __warn+0x80/0x92
    [42760.698549] [<68915d41>] warn_slowpath_null+0x28/0x36
    [42760.705912] [<f7c76c1c>] smp_call_function_many+0x88/0x20c
    [42760.713696] [<6bbdfc2a>] arch_trigger_cpumask_backtrace+0x30/0x4a
    [42760.722216] [<f845bd33>] rcu_dump_cpu_stacks+0x6a/0x98
    [42760.729580] [<796e7629>] rcu_check_callbacks+0x672/0x6ac
    [42760.737476] [<059b3b43>] update_process_times+0x18/0x34
    [42760.744981] [<6eb94941>] tick_sched_handle.isra.5+0x26/0x38
    [42760.752793] [<478d3d70>] tick_sched_timer+0x1c/0x50
    [42760.759882] [<e56ea39f>] __hrtimer_run_queues+0xc6/0x226
    [42760.767418] [<e88bbcae>] hrtimer_interrupt+0x88/0x19a
    [42760.775031] [<6765a19e>] gic_compare_interrupt+0x2e/0x3a
    [42760.782761] [<0558bf5f>] handle_percpu_devid_irq+0x78/0x168
    [42760.790795] [<90c11ba2>] generic_handle_irq+0x1e/0x2c
    [42760.798117] [<1b6d462c>] gic_handle_local_int+0x38/0x86
    [42760.805545] [<b2ada1c7>] gic_irq_dispatch+0xa/0x14
    [42760.812534] [<90c11ba2>] generic_handle_irq+0x1e/0x2c
    [42760.820086] [<c7521934>] do_IRQ+0x16/0x20
    [42760.826274] [<9aef3ce6>] plat_irq_dispatch+0x62/0x94
    [42760.833458] [<6a94b53c>] except_vec_vi_end+0x70/0x78
    [42760.840655] [<22284043>] smp_call_function_many+0x1ba/0x20c
    [42760.848501] [<54022b58>] smp_call_function+0x1e/0x2c
    [42760.855693] [<ab9fc705>] flush_tlb_mm+0x2a/0x98
    [42760.862730] [<0844cdd0>] tlb_flush_mmu+0x1c/0x44
    [42760.869628] [<cb259b74>] arch_tlb_finish_mmu+0x26/0x3e
    [42760.877021] [<1aeaaf74>] tlb_finish_mmu+0x18/0x66
    [42760.883907] [<b3fce717>] exit_mmap+0x76/0xea
    [42760.890428] [<c4c8a2f6>] mmput+0x80/0x11a
    [42760.896632] [<a41a08f4>] do_exit+0x1f4/0x80c
    [42760.903158] [<ee01cef6>] do_group_exit+0x20/0x7e
    [42760.909990] [<13fa8d54>] __wake_up_parent+0x0/0x1e
    [42760.917045] [<46cf89d0>] smp_call_function_many+0x1a2/0x20c
    [42760.924893] [<8c21a93b>] syscall_common+0x14/0x1c
    [42760.931765] ---[ end trace 02aa09da9dc52a60 ]---
    [42760.938342] ------------[ cut here ]------------
    [42760.945311] WARNING: CPU: 2 PID: 1216 at kernel/smp.c:291 smp_call_function_single+0xee/0xf8
    ...

This patch switches MIPS' arch_trigger_cpumask_backtrace() to use async
IPIs & smp_call_function_single_async() in order to resolve this
problem. We ensure use of the pre-allocated call_single_data_t
structures is serialized by maintaining a cpumask indicating that
they're busy, and refusing to attempt to send an IPI when a CPU's bit is
set in this mask. This should only happen if a CPU hasn't responded to a
previous backtrace IPI - ie. if it's hung - and we print a warning to
the console in this case.

I've marked this for stable branches as far back as v4.9, to which it
applies cleanly. Strictly speaking the faulty MIPS implementation can be
traced further back to commit 856839b ("MIPS: Add
arch_trigger_all_cpu_backtrace() function") in v3.19, but kernel
versions v3.19 through v4.8 will require further work to backport due to
the rework performed in commit 9a01c3ed5cdb ("nmi_backtrace: add more
trigger_*_cpu_backtrace() methods").

Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19597/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.9+
Fixes: 856839b ("MIPS: Add arch_trigger_all_cpu_backtrace() function")
Fixes: 9a01c3ed5cdb ("nmi_backtrace: add more trigger_*_cpu_backtrace() methods")
[ Huacai: backported to 4.4: Restruction since generic NMI solution is unavailable ]
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 7, 2018
commit c604cb767049b78b3075497b80ebb8fd530ea2cc upstream.

My recent fix for dns_resolver_preparse() printing very long strings was
incomplete, as shown by syzbot which still managed to hit the
WARN_ONCE() in set_precision() by adding a crafted "dns_resolver" key:

    precision 50001 too large
    WARNING: CPU: 7 PID: 864 at lib/vsprintf.c:2164 vsnprintf+0x48a/0x5a0

The bug this time isn't just a printing bug, but also a logical error
when multiple options ("#"-separated strings) are given in the key
payload.  Specifically, when separating an option string into name and
value, if there is no value then the name is incorrectly considered to
end at the end of the key payload, rather than the end of the current
option.  This bypasses validation of the option length, and also means
that specifying multiple options is broken -- which presumably has gone
unnoticed as there is currently only one valid option anyway.

A similar problem also applied to option values, as the kstrtoul() when
parsing the "dnserror" option will read past the end of the current
option and into the next option.

Fix these bugs by correctly computing the length of the option name and
by copying the option value, null-terminated, into a temporary buffer.

Reproducer for the WARN_ONCE() that syzbot hit:

    perl -e 'print "#A#", "\0" x 50000' | keyctl padd dns_resolver desc @s

Reproducer for "dnserror" option being parsed incorrectly (expected
behavior is to fail when seeing the unknown option "foo", actual
behavior was to read the dnserror value as "1#foo" and fail there):

    perl -e 'print "#dnserror=1#foo\0"' | keyctl padd dns_resolver desc @s

Reported-by: syzbot <syzkaller@googlegroups.com>
Fixes: 4a2d789 ("DNS: If the DNS server returns an error, allow that to be cached [ver TinkerBoard#2]")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 7, 2018
commit 89da619bc18d79bca5304724c11d4ba3b67ce2c6 upstream.

Kernel panic when with high memory pressure, calltrace looks like,

PID: 21439 TASK: ffff881be3afedd0 CPU: 16 COMMAND: "java"
 #0 [ffff881ec7ed7630] machine_kexec at ffffffff81059beb
 TinkerBoard#1 [ffff881ec7ed7690] __crash_kexec at ffffffff81105942
 TinkerBoard#2 [ffff881ec7ed7760] crash_kexec at ffffffff81105a30
 TinkerBoard#3 [ffff881ec7ed7778] oops_end at ffffffff816902c8
 TinkerBoard#4 [ffff881ec7ed77a0] no_context at ffffffff8167ff46
 TinkerBoard#5 [ffff881ec7ed77f0] __bad_area_nosemaphore at ffffffff8167ffdc
 TinkerBoard#6 [ffff881ec7ed7838] __node_set at ffffffff81680300
 TinkerBoard#7 [ffff881ec7ed7860] __do_page_fault at ffffffff8169320f
 TinkerBoard#8 [ffff881ec7ed78c0] do_page_fault at ffffffff816932b5
 TinkerBoard#9 [ffff881ec7ed78f0] page_fault at ffffffff8168f4c8
    [exception RIP: _raw_spin_lock_irqsave+47]
    RIP: ffffffff8168edef RSP: ffff881ec7ed79a8 RFLAGS: 00010046
    RAX: 0000000000000246 RBX: ffffea0019740d00 RCX: ffff881ec7ed7fd8
    RDX: 0000000000020000 RSI: 0000000000000016 RDI: 0000000000000008
    RBP: ffff881ec7ed79a8 R8: 0000000000000246 R9: 000000000001a098
    R10: ffff88107ffda000 R11: 0000000000000000 R12: 0000000000000000
    R13: 0000000000000008 R14: ffff881ec7ed7a80 R15: ffff881be3afedd0
    ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018

It happens in the pagefault and results in double pagefault
during compacting pages when memory allocation fails.

Analysed the vmcore, the page leads to second pagefault is corrupted
with _mapcount=-256, but private=0.

It's caused by the race between migration and ballooning, and lock
missing in virtballoon_migratepage() of virtio_balloon driver.
This patch fix the bug.

Fixes: e225042 ("virtio_balloon: introduce migration primitives to balloon pages")
Cc: stable@vger.kernel.org
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Huang Chong <huang.chong@zte.com.cn>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 7, 2018
commit 4e1a720d0312fd510699032c7694a362a010170f upstream.

slub debug reported:

[  440.648642] =============================================================================
[  440.648649] BUG kmalloc-1024 (Tainted: G    BU     O   ): Poison overwritten
[  440.648651] -----------------------------------------------------------------------------

[  440.648655] INFO: 0xe70f4bec-0xe70f4bec. First byte 0x6a instead of 0x6b
[  440.648665] INFO: Allocated in sk_prot_alloc+0x6b/0xc6 age=33155 cpu=1 pid=1047
[  440.648671] 	___slab_alloc.constprop.24+0x1fc/0x292
[  440.648675] 	__slab_alloc.isra.18.constprop.23+0x1c/0x25
[  440.648677] 	__kmalloc+0xb6/0x17f
[  440.648680] 	sk_prot_alloc+0x6b/0xc6
[  440.648683] 	sk_alloc+0x1e/0xa1
[  440.648700] 	sco_sock_alloc.constprop.6+0x26/0xaf [bluetooth]
[  440.648716] 	sco_connect_cfm+0x166/0x281 [bluetooth]
[  440.648731] 	hci_conn_request_evt.isra.53+0x258/0x281 [bluetooth]
[  440.648746] 	hci_event_packet+0x28b/0x2326 [bluetooth]
[  440.648759] 	hci_rx_work+0x161/0x291 [bluetooth]
[  440.648764] 	process_one_work+0x163/0x2b2
[  440.648767] 	worker_thread+0x1a9/0x25c
[  440.648770] 	kthread+0xf8/0xfd
[  440.648774] 	ret_from_fork+0x2e/0x38
[  440.648779] INFO: Freed in __sk_destruct+0xd3/0xdf age=3815 cpu=1 pid=1047
[  440.648782] 	__slab_free+0x4b/0x27a
[  440.648784] 	kfree+0x12e/0x155
[  440.648787] 	__sk_destruct+0xd3/0xdf
[  440.648790] 	sk_destruct+0x27/0x29
[  440.648793] 	__sk_free+0x75/0x91
[  440.648795] 	sk_free+0x1c/0x1e
[  440.648810] 	sco_sock_kill+0x5a/0x5f [bluetooth]
[  440.648825] 	sco_conn_del+0x8e/0xba [bluetooth]
[  440.648840] 	sco_disconn_cfm+0x3a/0x41 [bluetooth]
[  440.648855] 	hci_event_packet+0x45e/0x2326 [bluetooth]
[  440.648868] 	hci_rx_work+0x161/0x291 [bluetooth]
[  440.648872] 	process_one_work+0x163/0x2b2
[  440.648875] 	worker_thread+0x1a9/0x25c
[  440.648877] 	kthread+0xf8/0xfd
[  440.648880] 	ret_from_fork+0x2e/0x38
[  440.648884] INFO: Slab 0xf4718580 objects=27 used=27 fp=0x  (null) flags=0x40008100
[  440.648886] INFO: Object 0xe70f4b88 @offset=19336 fp=0xe70f54f8

When KASAN was enabled, it reported:

[  210.096613] ==================================================================
[  210.096634] BUG: KASAN: use-after-free in ex_handler_refcount+0x5b/0x127
[  210.096641] Write of size 4 at addr ffff880107e17160 by task kworker/u9:1/2040

[  210.096651] CPU: 1 PID: 2040 Comm: kworker/u9:1 Tainted: G     U     O    4.14.47-20180606+ TinkerBoard#2
[  210.096654] Hardware name: , BIOS 2017.01-00087-g43e04de 08/30/2017
[  210.096693] Workqueue: hci0 hci_rx_work [bluetooth]
[  210.096698] Call Trace:
[  210.096711]  dump_stack+0x46/0x59
[  210.096722]  print_address_description+0x6b/0x23b
[  210.096729]  ? ex_handler_refcount+0x5b/0x127
[  210.096736]  kasan_report+0x220/0x246
[  210.096744]  ex_handler_refcount+0x5b/0x127
[  210.096751]  ? ex_handler_clear_fs+0x85/0x85
[  210.096757]  fixup_exception+0x8c/0x96
[  210.096766]  do_trap+0x66/0x2c1
[  210.096773]  do_error_trap+0x152/0x180
[  210.096781]  ? fixup_bug+0x78/0x78
[  210.096817]  ? hci_debugfs_create_conn+0x244/0x26a [bluetooth]
[  210.096824]  ? __schedule+0x113b/0x1453
[  210.096830]  ? sysctl_net_exit+0xe/0xe
[  210.096837]  ? __wake_up_common+0x343/0x343
[  210.096843]  ? insert_work+0x107/0x163
[  210.096850]  invalid_op+0x1b/0x40
[  210.096888] RIP: 0010:hci_debugfs_create_conn+0x244/0x26a [bluetooth]
[  210.096892] RSP: 0018:ffff880094a0f970 EFLAGS: 00010296
[  210.096898] RAX: 0000000000000000 RBX: ffff880107e170e8 RCX: ffff880107e17160
[  210.096902] RDX: 000000000000002f RSI: ffff88013b80ed40 RDI: ffffffffa058b940
[  210.096906] RBP: ffff88011b2b0578 R08: 00000000852f0ec9 R09: ffffffff81cfcf9b
[  210.096909] R10: 00000000d21bdad7 R11: 0000000000000001 R12: ffff8800967b0488
[  210.096913] R13: ffff880107e17168 R14: 0000000000000068 R15: ffff8800949c0008
[  210.096920]  ? __sk_destruct+0x2c6/0x2d4
[  210.096959]  hci_event_packet+0xff5/0x7de2 [bluetooth]
[  210.096969]  ? __local_bh_enable_ip+0x43/0x5b
[  210.097004]  ? l2cap_sock_recv_cb+0x158/0x166 [bluetooth]
[  210.097039]  ? hci_le_meta_evt+0x2bb3/0x2bb3 [bluetooth]
[  210.097075]  ? l2cap_ertm_init+0x94e/0x94e [bluetooth]
[  210.097093]  ? xhci_urb_enqueue+0xbd8/0xcf5 [xhci_hcd]
[  210.097102]  ? __accumulate_pelt_segments+0x24/0x33
[  210.097109]  ? __accumulate_pelt_segments+0x24/0x33
[  210.097115]  ? __update_load_avg_se.isra.2+0x217/0x3a4
[  210.097122]  ? set_next_entity+0x7c3/0x12cd
[  210.097128]  ? pick_next_entity+0x25e/0x26c
[  210.097135]  ? pick_next_task_fair+0x2ca/0xc1a
[  210.097141]  ? switch_mm_irqs_off+0x346/0xb4f
[  210.097147]  ? __switch_to+0x769/0xbc4
[  210.097153]  ? compat_start_thread+0x66/0x66
[  210.097188]  ? hci_conn_check_link_mode+0x1cd/0x1cd [bluetooth]
[  210.097195]  ? finish_task_switch+0x392/0x431
[  210.097228]  ? hci_rx_work+0x154/0x487 [bluetooth]
[  210.097260]  hci_rx_work+0x154/0x487 [bluetooth]
[  210.097269]  process_one_work+0x579/0x9e9
[  210.097277]  worker_thread+0x68f/0x804
[  210.097285]  kthread+0x31c/0x32b
[  210.097292]  ? rescuer_thread+0x70c/0x70c
[  210.097299]  ? kthread_create_on_node+0xa3/0xa3
[  210.097306]  ret_from_fork+0x35/0x40

[  210.097314] Allocated by task 2040:
[  210.097323]  kasan_kmalloc.part.1+0x51/0xc7
[  210.097328]  __kmalloc+0x17f/0x1b6
[  210.097335]  sk_prot_alloc+0xf2/0x1a3
[  210.097340]  sk_alloc+0x22/0x297
[  210.097375]  sco_sock_alloc.constprop.7+0x23/0x202 [bluetooth]
[  210.097410]  sco_connect_cfm+0x2d0/0x566 [bluetooth]
[  210.097443]  hci_conn_request_evt.isra.53+0x6d3/0x762 [bluetooth]
[  210.097476]  hci_event_packet+0x85e/0x7de2 [bluetooth]
[  210.097507]  hci_rx_work+0x154/0x487 [bluetooth]
[  210.097512]  process_one_work+0x579/0x9e9
[  210.097517]  worker_thread+0x68f/0x804
[  210.097523]  kthread+0x31c/0x32b
[  210.097529]  ret_from_fork+0x35/0x40

[  210.097533] Freed by task 2040:
[  210.097539]  kasan_slab_free+0xb3/0x15e
[  210.097544]  kfree+0x103/0x1a9
[  210.097549]  __sk_destruct+0x2c6/0x2d4
[  210.097584]  sco_conn_del.isra.1+0xba/0x10e [bluetooth]
[  210.097617]  hci_event_packet+0xff5/0x7de2 [bluetooth]
[  210.097648]  hci_rx_work+0x154/0x487 [bluetooth]
[  210.097653]  process_one_work+0x579/0x9e9
[  210.097658]  worker_thread+0x68f/0x804
[  210.097663]  kthread+0x31c/0x32b
[  210.097670]  ret_from_fork+0x35/0x40

[  210.097676] The buggy address belongs to the object at ffff880107e170e8
 which belongs to the cache kmalloc-1024 of size 1024
[  210.097681] The buggy address is located 120 bytes inside of
 1024-byte region [ffff880107e170e8, ffff880107e174e8)
[  210.097683] The buggy address belongs to the page:
[  210.097689] page:ffffea00041f8400 count:1 mapcount:0 mapping:          (null) index:0xffff880107e15b68 compound_mapcount: 0
[  210.110194] flags: 0x8000000000008100(slab|head)
[  210.115441] raw: 8000000000008100 0000000000000000 ffff880107e15b68 0000000100170016
[  210.115448] raw: ffffea0004a47620 ffffea0004b48e20 ffff88013b80ed40 0000000000000000
[  210.115451] page dumped because: kasan: bad access detected

[  210.115454] Memory state around the buggy address:
[  210.115460]  ffff880107e17000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[  210.115465]  ffff880107e17080: fc fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb
[  210.115469] >ffff880107e17100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  210.115472]                                                        ^
[  210.115477]  ffff880107e17180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  210.115481]  ffff880107e17200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[  210.115483] ==================================================================

And finally when BT_DBG() and ftrace was enabled it showed:

       <...>-14979 [001] ....   186.104191: sco_sock_kill <-sco_sock_close
       <...>-14979 [001] ....   186.104191: sco_sock_kill <-sco_sock_release
       <...>-14979 [001] ....   186.104192: sco_sock_kill: sk ef0497a0 state 9
       <...>-14979 [001] ....   186.104193: bt_sock_unlink <-sco_sock_kill
kworker/u9:2-792   [001] ....   186.104246: sco_sock_kill <-sco_conn_del
kworker/u9:2-792   [001] ....   186.104248: sco_sock_kill: sk ef0497a0 state 9
kworker/u9:2-792   [001] ....   186.104249: bt_sock_unlink <-sco_sock_kill
kworker/u9:2-792   [001] ....   186.104250: sco_sock_destruct <-__sk_destruct
kworker/u9:2-792   [001] ....   186.104250: sco_sock_destruct: sk ef0497a0
kworker/u9:2-792   [001] ....   186.104860: hci_conn_del <-hci_event_packet
kworker/u9:2-792   [001] ....   186.104864: hci_conn_del: hci0 hcon ef0484c0 handle 266

Only in the failed case, sco_sock_kill() gets called with the same sock
pointer two times. Add a check for SOCK_DEAD to avoid continue killing
a socket which has already been killed.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bauuuuu pushed a commit to Bauuuuu/debian_kernel that referenced this issue Dec 7, 2018
commit ccd5b3235180eef3cfec337df1c8554ab151b5cc upstream.

The following commit:

  39a0526fb3f7 ("x86/mm: Factor out LDT init from context init")

renamed init_new_context() to init_new_context_ldt() and added a new
init_new_context() which calls init_new_context_ldt().  However, the
error code of init_new_context_ldt() was ignored.  Consequently, if a
memory allocation in alloc_ldt_struct() failed during a fork(), the
->context.ldt of the new task remained the same as that of the old task
(due to the memcpy() in dup_mm()).  ldt_struct's are not intended to be
shared, so a use-after-free occurred after one task exited.

Fix the bug by making init_new_context() pass through the error code of
init_new_context_ldt().

This bug was found by syzkaller, which encountered the following splat:

    BUG: KASAN: use-after-free in free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116
    Read of size 4 at addr ffff88006d2cb7c8 by task kworker/u9:0/3710

    CPU: 1 PID: 3710 Comm: kworker/u9:0 Not tainted 4.13.0-rc4-next-20170811 TinkerBoard#2
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
    Call Trace:
     __dump_stack lib/dump_stack.c:16 [inline]
     dump_stack+0x194/0x257 lib/dump_stack.c:52
     print_address_description+0x73/0x250 mm/kasan/report.c:252
     kasan_report_error mm/kasan/report.c:351 [inline]
     kasan_report+0x24e/0x340 mm/kasan/report.c:409
     __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429
     free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116
     free_ldt_struct arch/x86/kernel/ldt.c:173 [inline]
     destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171
     destroy_context arch/x86/include/asm/mmu_context.h:157 [inline]
     __mmdrop+0xe9/0x530 kernel/fork.c:889
     mmdrop include/linux/sched/mm.h:42 [inline]
     exec_mmap fs/exec.c:1061 [inline]
     flush_old_exec+0x173c/0x1ff0 fs/exec.c:1291
     load_elf_binary+0x81f/0x4ba0 fs/binfmt_elf.c:855
     search_binary_handler+0x142/0x6b0 fs/exec.c:1652
     exec_binprm fs/exec.c:1694 [inline]
     do_execveat_common.isra.33+0x1746/0x22e0 fs/exec.c:1816
     do_execve+0x31/0x40 fs/exec.c:1860
     call_usermodehelper_exec_async+0x457/0x8f0 kernel/umh.c:100
     ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431

    Allocated by task 3700:
     save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
     save_stack+0x43/0xd0 mm/kasan/kasan.c:447
     set_track mm/kasan/kasan.c:459 [inline]
     kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
     kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627
     kmalloc include/linux/slab.h:493 [inline]
     alloc_ldt_struct+0x52/0x140 arch/x86/kernel/ldt.c:67
     write_ldt+0x7b7/0xab0 arch/x86/kernel/ldt.c:277
     sys_modify_ldt+0x1ef/0x240 arch/x86/kernel/ldt.c:307
     entry_SYSCALL_64_fastpath+0x1f/0xbe

    Freed by task 3700:
     save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
     save_stack+0x43/0xd0 mm/kasan/kasan.c:447
     set_track mm/kasan/kasan.c:459 [inline]
     kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
     __cache_free mm/slab.c:3503 [inline]
     kfree+0xca/0x250 mm/slab.c:3820
     free_ldt_struct.part.2+0xdd/0x150 arch/x86/kernel/ldt.c:121
     free_ldt_struct arch/x86/kernel/ldt.c:173 [inline]
     destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171
     destroy_context arch/x86/include/asm/mmu_context.h:157 [inline]
     __mmdrop+0xe9/0x530 kernel/fork.c:889
     mmdrop include/linux/sched/mm.h:42 [inline]
     __mmput kernel/fork.c:916 [inline]
     mmput+0x541/0x6e0 kernel/fork.c:927
     copy_process.part.36+0x22e1/0x4af0 kernel/fork.c:1931
     copy_process kernel/fork.c:1546 [inline]
     _do_fork+0x1ef/0xfb0 kernel/fork.c:2025
     SYSC_clone kernel/fork.c:2135 [inline]
     SyS_clone+0x37/0x50 kernel/fork.c:2129
     do_syscall_64+0x26c/0x8c0 arch/x86/entry/common.c:287
     return_from_SYSCALL_64+0x0/0x7a

Here is a C reproducer:

    #include <asm/ldt.h>
    #include <pthread.h>
    #include <signal.h>
    #include <stdlib.h>
    #include <sys/syscall.h>
    #include <sys/wait.h>
    #include <unistd.h>

    static void *fork_thread(void *_arg)
    {
        fork();
    }

    int main(void)
    {
        struct user_desc desc = { .entry_number = 8191 };

        syscall(__NR_modify_ldt, 1, &desc, sizeof(desc));

        for (;;) {
            if (fork() == 0) {
                pthread_t t;

                srand(getpid());
                pthread_create(&t, NULL, fork_thread, NULL);
                usleep(rand() % 10000);
                syscall(__NR_exit_group, 0);
            }
            wait(NULL);
        }
    }

Note: the reproducer takes advantage of the fact that alloc_ldt_struct()
may use vmalloc() to allocate a large ->entries array, and after
commit:

  5d17a73a2ebe ("vmalloc: back off when the current task is killed")

it is possible for userspace to fail a task's vmalloc() by
sending a fatal signal, e.g. via exit_group().  It would be more
difficult to reproduce this bug on kernels without that commit.

This bug only affected kernels with CONFIG_MODIFY_LDT_SYSCALL=y.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: <stable@vger.kernel.org> [v4.6+]
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Fixes: 39a0526fb3f7 ("x86/mm: Factor out LDT init from context init")
Link: http://lkml.kernel.org/r/20170824175029.76040-1-ebiggers3@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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