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Display won't wake up after suspend #38

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Quarx2k opened this issue Jun 15, 2012 · 9 comments
Closed

Display won't wake up after suspend #38

Quarx2k opened this issue Jun 15, 2012 · 9 comments

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@Quarx2k
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Quarx2k commented Jun 15, 2012

On first boot the display is works. After suspend display won't wake up (only backlight), touchscreen works on black screen. HDMI works after sleep, wake up without problem.
This problem only for Ainol Novo 7 Aurora (not see this problem on any other a10-based device)
No errors in dmesg,
Resolve the problem: Quarx2k@31974a2
But it cause very big battery drain in idle mode.

New info: Aurora use SPI interface module. In current kernel tree missing drivers for spi.
If i disable the "cd_spi_para", display can't wakeup on ainol kernel too.
https://gist.github.com/2979796

@killerkink
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This happened to p76ti as well. Even the 3.0.8 branch. But in the case of p76ti, going to sleep cause tablet to reboot.

Allwinner Qware 3.0.8 source work without issue.

@Quarx2k
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Quarx2k commented Jun 16, 2012

At night in idle - battery drop from 100% to 48%.. is not good:(
Allwinner Qware 3.0.8 don't works too
Ok, found new fix. ticket updated.

@amery
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amery commented Jul 4, 2012

I've ported a patch from allwinner to our 3.0-v2 (6c01b6c) which doesn't only include lcd_spi but also a bunch of improvements in other areas of disp. it would be awesome if you could test it.

@Quarx2k
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Quarx2k commented Jul 5, 2012

No problems, i set:
CONFIG_LYCHEE_FB_SUN4I=y
CONFIG_LYCHEE_LCD_SUN4I=y
CONFIG_LYCHEE_LCD_AINOL_AUROTA=y
CONFIG_LYCHEE_HDMI_SUN4I=y

And please rename AUROTA to AURORA :)

Problem: HDMI is green display... Photo: http://quarx2k.ru/.temp/IMG_20120705_141842.jpg
Explanation: By default now HDMI Display mode: YUV, by switch to RGB(on monitor), picture is correct.

@amery
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amery commented Jul 5, 2012

should we find a way to change that default somehow back to RGB or YUV is fine?

@Quarx2k
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Quarx2k commented Jul 5, 2012

we should find way to change back to RGB.
Because YUV is green :p
+//out_csc: 0:rgb, 1:yuv for tv, 2:yuv for hdmi
+//out_color_range: 0:16255, 1:0255, 2:16~235

@amery
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amery commented Jul 5, 2012

amery@6c01b6c#L1R189 sets the TV type to YUV, not the HDMI....

@Quarx2k
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Quarx2k commented Jul 5, 2012

I tried to set out_csc =1 for HDMI, colors now looks badly than with 0.
Maybe problem with out_color_range

@amery
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amery commented Sep 10, 2012

0a3d1af added lcd_spi support, while the part that causes this green hdmi output effect has been moved for future research into the wip/linux-sunxi-3.0/disp branch.

@amery amery closed this as completed Sep 10, 2012
amery pushed a commit that referenced this issue Apr 30, 2013
There was sync mutex which was held over userspace. That is very
wrong and could cause deadlock if different userspace process is
used to "unlock". Wait queue seems to be correct solution for
that kind of synchronizing issue so use it instead.
lock debug gives following bug report:
================================================
[ BUG: lock held when returning to user space! ]
3.9.0-rc1+ #38 Tainted: G           O
------------------------------------------------
tzap/4614 is leaving the kernel with locks still held!
1 lock held by tzap/4614:

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
amery pushed a commit that referenced this issue Nov 12, 2013
As the new x86 CPU bootup printout format code maintainer, I am
taking immediate action to improve and clean (and thus indulge
my OCD) the reporting of the cores when coming up online.

Fix padding to a right-hand alignment, cleanup code and bind
reporting width to the max number of supported CPUs on the
system, like this:

 [    0.074509] smpboot: Booting Node   0, Processors:      #1  #2  #3  #4  #5  #6  #7 OK
 [    0.644008] smpboot: Booting Node   1, Processors:  #8  #9 #10 #11 #12 #13 #14 #15 OK
 [    1.245006] smpboot: Booting Node   2, Processors: #16 #17 #18 #19 #20 #21 #22 #23 OK
 [    1.864005] smpboot: Booting Node   3, Processors: #24 #25 #26 #27 #28 #29 #30 #31 OK
 [    2.489005] smpboot: Booting Node   4, Processors: #32 #33 #34 #35 #36 #37 #38 #39 OK
 [    3.093005] smpboot: Booting Node   5, Processors: #40 #41 #42 #43 #44 #45 #46 #47 OK
 [    3.698005] smpboot: Booting Node   6, Processors: #48 #49 #50 #51 #52 #53 #54 #55 OK
 [    4.304005] smpboot: Booting Node   7, Processors: #56 #57 #58 #59 #60 #61 #62 #63 OK
 [    4.961413] Brought up 64 CPUs

and this:

 [    0.072367] smpboot: Booting Node   0, Processors:    #1 #2 #3 #4 #5 #6 #7 OK
 [    0.686329] Brought up 8 CPUs

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Libin <huawei.libin@huawei.com>
Cc: wangyijing@huawei.com
Cc: fenghua.yu@intel.com
Cc: guohanjun@huawei.com
Cc: paul.gortmaker@windriver.com
Link: http://lkml.kernel.org/r/20130927143554.GF4422@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
amery pushed a commit that referenced this issue Nov 12, 2013
Turn it into (for example):

[    0.073380] x86: Booting SMP configuration:
[    0.074005] .... node   #0, CPUs:          #1   #2   #3   #4   #5   #6   #7
[    0.603005] .... node   #1, CPUs:     #8   #9  #10  #11  #12  #13  #14  #15
[    1.200005] .... node   #2, CPUs:    #16  #17  #18  #19  #20  #21  #22  #23
[    1.796005] .... node   #3, CPUs:    #24  #25  #26  #27  #28  #29  #30  #31
[    2.393005] .... node   #4, CPUs:    #32  #33  #34  #35  #36  #37  #38  #39
[    2.996005] .... node   #5, CPUs:    #40  #41  #42  #43  #44  #45  #46  #47
[    3.600005] .... node   #6, CPUs:    #48  #49  #50  #51  #52  #53  #54  #55
[    4.202005] .... node   #7, CPUs:    #56  #57  #58  #59  #60  #61  #62  #63
[    4.811005] .... node   #8, CPUs:    #64  #65  #66  #67  #68  #69  #70  #71
[    5.421006] .... node   #9, CPUs:    #72  #73  #74  #75  #76  #77  #78  #79
[    6.032005] .... node  #10, CPUs:    #80  #81  #82  #83  #84  #85  #86  #87
[    6.648006] .... node  #11, CPUs:    #88  #89  #90  #91  #92  #93  #94  #95
[    7.262005] .... node  #12, CPUs:    #96  #97  #98  #99 #100 #101 #102 #103
[    7.865005] .... node  #13, CPUs:   #104 #105 #106 #107 #108 #109 #110 #111
[    8.466005] .... node  #14, CPUs:   #112 #113 #114 #115 #116 #117 #118 #119
[    9.073006] .... node  #15, CPUs:   #120 #121 #122 #123 #124 #125 #126 #127
[    9.679901] x86: Booted up 16 nodes, 128 CPUs

and drop useless elements.

Change num_digits() to hpa's division-avoiding, cell-phone-typed
version which he went at great lengths and pains to submit on a
Saturday evening.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: huawei.libin@huawei.com
Cc: wangyijing@huawei.com
Cc: fenghua.yu@intel.com
Cc: guohanjun@huawei.com
Cc: paul.gortmaker@windriver.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20130930095624.GB16383@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
amery pushed a commit that referenced this issue Nov 16, 2013
…hing

Dave Jones reported that trinity would be able to trigger the following
back trace:

 ===============================
 [ INFO: suspicious RCU usage. ]
 3.10.0-rc2+ #38 Not tainted
 -------------------------------
 include/linux/rcupdate.h:771 rcu_read_lock() used illegally while idle!
 other info that might help us debug this:

 RCU used illegally from idle CPU!  rcu_scheduler_active = 1, debug_locks = 0
 RCU used illegally from extended quiescent state!
 1 lock held by trinity-child1/18786:
  #0:  (rcu_read_lock){.+.+..}, at: [<ffffffff8113dd48>] __perf_event_overflow+0x108/0x310
 stack backtrace:
 CPU: 3 PID: 18786 Comm: trinity-child1 Not tainted 3.10.0-rc2+ #38
  0000000000000000 ffff88020767bac8 ffffffff816e2f6b ffff88020767baf8
  ffffffff810b5897 ffff88021de92520 0000000000000000 ffff88020767bbf8
  0000000000000000 ffff88020767bb78 ffffffff8113ded4 ffffffff8113dd48
 Call Trace:
  [<ffffffff816e2f6b>] dump_stack+0x19/0x1b
  [<ffffffff810b5897>] lockdep_rcu_suspicious+0xe7/0x120
  [<ffffffff8113ded4>] __perf_event_overflow+0x294/0x310
  [<ffffffff8113dd48>] ? __perf_event_overflow+0x108/0x310
  [<ffffffff81309289>] ? __const_udelay+0x29/0x30
  [<ffffffff81076054>] ? __rcu_read_unlock+0x54/0xa0
  [<ffffffff816f4000>] ? ftrace_call+0x5/0x2f
  [<ffffffff8113dfa1>] perf_swevent_overflow+0x51/0xe0
  [<ffffffff8113e08f>] perf_swevent_event+0x5f/0x90
  [<ffffffff8113e1c9>] perf_tp_event+0x109/0x4f0
  [<ffffffff8113e36f>] ? perf_tp_event+0x2af/0x4f0
  [<ffffffff81074630>] ? __rcu_read_lock+0x20/0x20
  [<ffffffff8112d79f>] perf_ftrace_function_call+0xbf/0xd0
  [<ffffffff8110e1e1>] ? ftrace_ops_control_func+0x181/0x210
  [<ffffffff81074630>] ? __rcu_read_lock+0x20/0x20
  [<ffffffff81100cae>] ? rcu_eqs_enter_common+0x5e/0x470
  [<ffffffff8110e1e1>] ftrace_ops_control_func+0x181/0x210
  [<ffffffff816f4000>] ftrace_call+0x5/0x2f
  [<ffffffff8110e229>] ? ftrace_ops_control_func+0x1c9/0x210
  [<ffffffff816f4000>] ? ftrace_call+0x5/0x2f
  [<ffffffff81074635>] ? debug_lockdep_rcu_enabled+0x5/0x40
  [<ffffffff81074635>] ? debug_lockdep_rcu_enabled+0x5/0x40
  [<ffffffff81100cae>] ? rcu_eqs_enter_common+0x5e/0x470
  [<ffffffff8110112a>] rcu_eqs_enter+0x6a/0xb0
  [<ffffffff81103673>] rcu_user_enter+0x13/0x20
  [<ffffffff8114541a>] user_enter+0x6a/0xd0
  [<ffffffff8100f6d8>] syscall_trace_leave+0x78/0x140
  [<ffffffff816f46af>] int_check_syscall_exit_work+0x34/0x3d
 ------------[ cut here ]------------

Perf uses rcu_read_lock() but as the function tracer can trace functions
even when RCU is not currently active, this makes the rcu_read_lock()
used by perf ineffective.

As perf is currently the only user of the ftrace_ops_control_func() and
perf is also the only function callback that actively uses rcu_read_lock(),
the quick fix is to prevent the ftrace_ops_control_func() from calling
its callbacks if RCU is not active.

With Paul's new "rcu_is_watching()" we can tell if RCU is active or not.

Reported-by: Dave Jones <davej@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
amery pushed a commit that referenced this issue Jan 24, 2014
Command "tcrypt sec=1 mode=403" give the follwoing error for Polling
mode:
root@am335x-evm:/# insmod tcrypt.ko sec=1 mode=403
[...]

[  346.982754] test 15 ( 4096 byte blocks, 1024 bytes per update,   4 updates):   4352 opers/sec,  17825792 bytes/sec
[  347.992661] test 16 ( 4096 byte blocks, 4096 bytes per update,   1 updates):   7095 opers/sec,  29061120 bytes/sec
[  349.002667] test 17 ( 8192 byte blocks,   16 bytes per update, 512 updates):
[  349.010882] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[  349.020037] pgd = ddeac000
[  349.022884] [00000000] *pgd=9dcb4831, *pte=00000000, *ppte=00000000
[  349.029816] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[  349.035482] Modules linked in: tcrypt(+)
[  349.039617] CPU: 0 PID: 1473 Comm: insmod Not tainted 3.12.4-01566-g6279006-dirty #38
[  349.047832] task: dda91540 ti: ddcd2000 task.ti: ddcd2000
[  349.053517] PC is at omap_sham_xmit_dma+0x6c/0x238
[  349.058544] LR is at omap_sham_xmit_dma+0x38/0x238
[  349.063570] pc : [<c04eb7cc>]    lr : [<c04eb798>]    psr: 20000013
[  349.063570] sp : ddcd3c78  ip : 00000000  fp : 9d8980b8
[  349.075610] r10: 00000000  r9 : 00000000  r8 : 00000000
[  349.081090] r7 : 00001000  r6 : dd898000  r5 : 00000040  r4 : ddb10550
[  349.087935] r3 : 00000004  r2 : 00000010  r1 : 53100080  r0 : 00000000
[  349.094783] Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[  349.102268] Control: 10c5387d  Table: 9deac019  DAC: 00000015
[  349.108294] Process insmod (pid: 1473, stack limit = 0xddcd2248)

[...]

This is because polling_mode is not enabled for ctx without FLAGS_FINUP.

For polling mode the bufcnt is made 0 unconditionally. But it should be made 0
only if it is a final update or a total is not zero(This condition is similar
to what is done in DMA case). Because of this wrong hashes are produced.

Fixing the same.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
amery pushed a commit that referenced this issue Oct 29, 2014
This patch wires up the new syscall sys_bpf() on powerpc.

Passes the tests in samples/bpf:

    #0 add+sub+mul OK
    #1 unreachable OK
    #2 unreachable2 OK
    #3 out of range jump OK
    #4 out of range jump2 OK
    #5 test1 ld_imm64 OK
    #6 test2 ld_imm64 OK
    #7 test3 ld_imm64 OK
    #8 test4 ld_imm64 OK
    #9 test5 ld_imm64 OK
    #10 no bpf_exit OK
    #11 loop (back-edge) OK
    #12 loop2 (back-edge) OK
    #13 conditional loop OK
    #14 read uninitialized register OK
    #15 read invalid register OK
    #16 program doesn't init R0 before exit OK
    #17 stack out of bounds OK
    #18 invalid call insn1 OK
    #19 invalid call insn2 OK
    #20 invalid function call OK
    #21 uninitialized stack1 OK
    #22 uninitialized stack2 OK
    #23 check valid spill/fill OK
    #24 check corrupted spill/fill OK
    #25 invalid src register in STX OK
    #26 invalid dst register in STX OK
    #27 invalid dst register in ST OK
    #28 invalid src register in LDX OK
    #29 invalid dst register in LDX OK
    #30 junk insn OK
    #31 junk insn2 OK
    #32 junk insn3 OK
    #33 junk insn4 OK
    #34 junk insn5 OK
    #35 misaligned read from stack OK
    #36 invalid map_fd for function call OK
    #37 don't check return value before access OK
    #38 access memory with incorrect alignment OK
    #39 sometimes access memory with incorrect alignment OK
    #40 jump test 1 OK
    #41 jump test 2 OK
    #42 jump test 3 OK
    #43 jump test 4 OK

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
[mpe: test using samples/bpf]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
hramrach pushed a commit to hramrach/linux-sunxi that referenced this issue Aug 11, 2015
Nikolay has reported a hang when a memcg reclaim got stuck with the
following backtrace:

PID: 18308  TASK: ffff883d7c9b0a30  CPU: 1   COMMAND: "rsync"
  #0 __schedule at ffffffff815ab152
  linux-sunxi#1 schedule at ffffffff815ab76e
  linux-sunxi#2 schedule_timeout at ffffffff815ae5e5
  linux-sunxi#3 io_schedule_timeout at ffffffff815aad6a
  linux-sunxi#4 bit_wait_io at ffffffff815abfc6
  linux-sunxi#5 __wait_on_bit at ffffffff815abda5
  linux-sunxi#6 wait_on_page_bit at ffffffff8111fd4f
  linux-sunxi#7 shrink_page_list at ffffffff81135445
  linux-sunxi#8 shrink_inactive_list at ffffffff81135845
  linux-sunxi#9 shrink_lruvec at ffffffff81135ead
 linux-sunxi#10 shrink_zone at ffffffff811360c3
 linux-sunxi#11 shrink_zones at ffffffff81136eff
 linux-sunxi#12 do_try_to_free_pages at ffffffff8113712f
 linux-sunxi#13 try_to_free_mem_cgroup_pages at ffffffff811372be
 linux-sunxi#14 try_charge at ffffffff81189423
 linux-sunxi#15 mem_cgroup_try_charge at ffffffff8118c6f5
 linux-sunxi#16 __add_to_page_cache_locked at ffffffff8112137d
 linux-sunxi#17 add_to_page_cache_lru at ffffffff81121618
 linux-sunxi#18 pagecache_get_page at ffffffff8112170b
 linux-sunxi#19 grow_dev_page at ffffffff811c8297
 linux-sunxi#20 __getblk_slow at ffffffff811c91d6
 linux-sunxi#21 __getblk_gfp at ffffffff811c92c1
 linux-sunxi#22 ext4_ext_grow_indepth at ffffffff8124565c
 linux-sunxi#23 ext4_ext_create_new_leaf at ffffffff81246ca8
 linux-sunxi#24 ext4_ext_insert_extent at ffffffff81246f09
 linux-sunxi#25 ext4_ext_map_blocks at ffffffff8124a848
 linux-sunxi#26 ext4_map_blocks at ffffffff8121a5b7
 linux-sunxi#27 mpage_map_one_extent at ffffffff8121b1fa
 linux-sunxi#28 mpage_map_and_submit_extent at ffffffff8121f07b
 linux-sunxi#29 ext4_writepages at ffffffff8121f6d5
 linux-sunxi#30 do_writepages at ffffffff8112c490
 linux-sunxi#31 __filemap_fdatawrite_range at ffffffff81120199
 linux-sunxi#32 filemap_flush at ffffffff8112041c
 linux-sunxi#33 ext4_alloc_da_blocks at ffffffff81219da1
 linux-sunxi#34 ext4_rename at ffffffff81229b91
 linux-sunxi#35 ext4_rename2 at ffffffff81229e32
 linux-sunxi#36 vfs_rename at ffffffff811a08a5
 linux-sunxi#37 SYSC_renameat2 at ffffffff811a3ffc
 linux-sunxi#38 sys_renameat2 at ffffffff811a408e
 linux-sunxi#39 sys_rename at ffffffff8119e51e
 linux-sunxi#40 system_call_fastpath at ffffffff815afa89

Dave Chinner has properly pointed out that this is a deadlock in the
reclaim code because ext4 doesn't submit pages which are marked by
PG_writeback right away.

The heuristic was introduced by commit e62e384 ("memcg: prevent OOM
with too many dirty pages") and it was applied only when may_enter_fs
was specified.  The code has been changed by c3b94f4 ("memcg:
further prevent OOM with too many dirty pages") which has removed the
__GFP_FS restriction with a reasoning that we do not get into the fs
code.  But this is not sufficient apparently because the fs doesn't
necessarily submit pages marked PG_writeback for IO right away.

ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily
submit the bio.  Instead it tries to map more pages into the bio and
mpage_map_one_extent might trigger memcg charge which might end up
waiting on a page which is marked PG_writeback but hasn't been submitted
yet so we would end up waiting for something that never finishes.

Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2)
before we go to wait on the writeback.  The page fault path, which is
the only path that triggers memcg oom killer since 3.12, shouldn't
require GFP_NOFS and so we shouldn't reintroduce the premature OOM
killer issue which was originally addressed by the heuristic.

As per David Chinner the xfs is doing similar thing since 2.6.15 already
so ext4 is not the only affected filesystem.  Moreover he notes:

: For example: IO completion might require unwritten extent conversion
: which executes filesystem transactions and GFP_NOFS allocations. The
: writeback flag on the pages can not be cleared until unwritten
: extent conversion completes. Hence memory reclaim cannot wait on
: page writeback to complete in GFP_NOFS context because it is not
: safe to do so, memcg reclaim or otherwise.

Cc: stable@vger.kernel.org # 3.9+
[tytso@mit.edu: corrected the control flow]
Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages")
Reported-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
amery pushed a commit that referenced this issue May 21, 2016
The binary GCD algorithm is based on the following facts:
	1. If a and b are all evens, then gcd(a,b) = 2 * gcd(a/2, b/2)
	2. If a is even and b is odd, then gcd(a,b) = gcd(a/2, b)
	3. If a and b are all odds, then gcd(a,b) = gcd((a-b)/2, b) = gcd((a+b)/2, b)

Even on x86 machines with reasonable division hardware, the binary
algorithm runs about 25% faster (80% the execution time) than the
division-based Euclidian algorithm.

On platforms like Alpha and ARMv6 where division is a function call to
emulation code, it's even more significant.

There are two variants of the code here, depending on whether a fast
__ffs (find least significant set bit) instruction is available.  This
allows the unpredictable branches in the bit-at-a-time shifting loop to
be eliminated.

If fast __ffs is not available, the "even/odd" GCD variant is used.

I use the following code to benchmark:

	#include <stdio.h>
	#include <stdlib.h>
	#include <stdint.h>
	#include <string.h>
	#include <time.h>
	#include <unistd.h>

	#define swap(a, b) \
		do { \
			a ^= b; \
			b ^= a; \
			a ^= b; \
		} while (0)

	unsigned long gcd0(unsigned long a, unsigned long b)
	{
		unsigned long r;

		if (a < b) {
			swap(a, b);
		}

		if (b == 0)
			return a;

		while ((r = a % b) != 0) {
			a = b;
			b = r;
		}

		return b;
	}

	unsigned long gcd1(unsigned long a, unsigned long b)
	{
		unsigned long r = a | b;

		if (!a || !b)
			return r;

		b >>= __builtin_ctzl(b);

		for (;;) {
			a >>= __builtin_ctzl(a);
			if (a == b)
				return a << __builtin_ctzl(r);

			if (a < b)
				swap(a, b);
			a -= b;
		}
	}

	unsigned long gcd2(unsigned long a, unsigned long b)
	{
		unsigned long r = a | b;

		if (!a || !b)
			return r;

		r &= -r;

		while (!(b & r))
			b >>= 1;

		for (;;) {
			while (!(a & r))
				a >>= 1;
			if (a == b)
				return a;

			if (a < b)
				swap(a, b);
			a -= b;
			a >>= 1;
			if (a & r)
				a += b;
			a >>= 1;
		}
	}

	unsigned long gcd3(unsigned long a, unsigned long b)
	{
		unsigned long r = a | b;

		if (!a || !b)
			return r;

		b >>= __builtin_ctzl(b);
		if (b == 1)
			return r & -r;

		for (;;) {
			a >>= __builtin_ctzl(a);
			if (a == 1)
				return r & -r;
			if (a == b)
				return a << __builtin_ctzl(r);

			if (a < b)
				swap(a, b);
			a -= b;
		}
	}

	unsigned long gcd4(unsigned long a, unsigned long b)
	{
		unsigned long r = a | b;

		if (!a || !b)
			return r;

		r &= -r;

		while (!(b & r))
			b >>= 1;
		if (b == r)
			return r;

		for (;;) {
			while (!(a & r))
				a >>= 1;
			if (a == r)
				return r;
			if (a == b)
				return a;

			if (a < b)
				swap(a, b);
			a -= b;
			a >>= 1;
			if (a & r)
				a += b;
			a >>= 1;
		}
	}

	static unsigned long (*gcd_func[])(unsigned long a, unsigned long b) = {
		gcd0, gcd1, gcd2, gcd3, gcd4,
	};

	#define TEST_ENTRIES (sizeof(gcd_func) / sizeof(gcd_func[0]))

	#if defined(__x86_64__)

	#define rdtscll(val) do { \
		unsigned long __a,__d; \
		__asm__ __volatile__("rdtsc" : "=a" (__a), "=d" (__d)); \
		(val) = ((unsigned long long)__a) | (((unsigned long long)__d)<<32); \
	} while(0)

	static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long),
								unsigned long a, unsigned long b, unsigned long *res)
	{
		unsigned long long start, end;
		unsigned long long ret;
		unsigned long gcd_res;

		rdtscll(start);
		gcd_res = gcd(a, b);
		rdtscll(end);

		if (end >= start)
			ret = end - start;
		else
			ret = ~0ULL - start + 1 + end;

		*res = gcd_res;
		return ret;
	}

	#else

	static inline struct timespec read_time(void)
	{
		struct timespec time;
		clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time);
		return time;
	}

	static inline unsigned long long diff_time(struct timespec start, struct timespec end)
	{
		struct timespec temp;

		if ((end.tv_nsec - start.tv_nsec) < 0) {
			temp.tv_sec = end.tv_sec - start.tv_sec - 1;
			temp.tv_nsec = 1000000000ULL + end.tv_nsec - start.tv_nsec;
		} else {
			temp.tv_sec = end.tv_sec - start.tv_sec;
			temp.tv_nsec = end.tv_nsec - start.tv_nsec;
		}

		return temp.tv_sec * 1000000000ULL + temp.tv_nsec;
	}

	static unsigned long long benchmark_gcd_func(unsigned long (*gcd)(unsigned long, unsigned long),
								unsigned long a, unsigned long b, unsigned long *res)
	{
		struct timespec start, end;
		unsigned long gcd_res;

		start = read_time();
		gcd_res = gcd(a, b);
		end = read_time();

		*res = gcd_res;
		return diff_time(start, end);
	}

	#endif

	static inline unsigned long get_rand()
	{
		if (sizeof(long) == 8)
			return (unsigned long)rand() << 32 | rand();
		else
			return rand();
	}

	int main(int argc, char **argv)
	{
		unsigned int seed = time(0);
		int loops = 100;
		int repeats = 1000;
		unsigned long (*res)[TEST_ENTRIES];
		unsigned long long elapsed[TEST_ENTRIES];
		int i, j, k;

		for (;;) {
			int opt = getopt(argc, argv, "n:r:s:");
			/* End condition always first */
			if (opt == -1)
				break;

			switch (opt) {
			case 'n':
				loops = atoi(optarg);
				break;
			case 'r':
				repeats = atoi(optarg);
				break;
			case 's':
				seed = strtoul(optarg, NULL, 10);
				break;
			default:
				/* You won't actually get here. */
				break;
			}
		}

		res = malloc(sizeof(unsigned long) * TEST_ENTRIES * loops);
		memset(elapsed, 0, sizeof(elapsed));

		srand(seed);
		for (j = 0; j < loops; j++) {
			unsigned long a = get_rand();
			/* Do we have args? */
			unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand();
			unsigned long long min_elapsed[TEST_ENTRIES];
			for (k = 0; k < repeats; k++) {
				for (i = 0; i < TEST_ENTRIES; i++) {
					unsigned long long tmp = benchmark_gcd_func(gcd_func[i], a, b, &res[j][i]);
					if (k == 0 || min_elapsed[i] > tmp)
						min_elapsed[i] = tmp;
				}
			}
			for (i = 0; i < TEST_ENTRIES; i++)
				elapsed[i] += min_elapsed[i];
		}

		for (i = 0; i < TEST_ENTRIES; i++)
			printf("gcd%d: elapsed %llu\n", i, elapsed[i]);

		k = 0;
		srand(seed);
		for (j = 0; j < loops; j++) {
			unsigned long a = get_rand();
			unsigned long b = argc > optind ? strtoul(argv[optind], NULL, 10) : get_rand();
			for (i = 1; i < TEST_ENTRIES; i++) {
				if (res[j][i] != res[j][0])
					break;
			}
			if (i < TEST_ENTRIES) {
				if (k == 0) {
					k = 1;
					fprintf(stderr, "Error:\n");
				}
				fprintf(stderr, "gcd(%lu, %lu): ", a, b);
				for (i = 0; i < TEST_ENTRIES; i++)
					fprintf(stderr, "%ld%s", res[j][i], i < TEST_ENTRIES - 1 ? ", " : "\n");
			}
		}

		if (k == 0)
			fprintf(stderr, "PASS\n");

		free(res);

		return 0;
	}

Compiled with "-O2", on "VirtualBox 4.4.0-22-generic #38-Ubuntu x86_64" got:

  zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
  gcd0: elapsed 10174
  gcd1: elapsed 2120
  gcd2: elapsed 2902
  gcd3: elapsed 2039
  gcd4: elapsed 2812
  PASS
  zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
  gcd0: elapsed 9309
  gcd1: elapsed 2280
  gcd2: elapsed 2822
  gcd3: elapsed 2217
  gcd4: elapsed 2710
  PASS
  zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
  gcd0: elapsed 9589
  gcd1: elapsed 2098
  gcd2: elapsed 2815
  gcd3: elapsed 2030
  gcd4: elapsed 2718
  PASS
  zhaoxiuzeng@zhaoxiuzeng-VirtualBox:~/develop$ ./gcd -r 500000 -n 10
  gcd0: elapsed 9914
  gcd1: elapsed 2309
  gcd2: elapsed 2779
  gcd3: elapsed 2228
  gcd4: elapsed 2709
  PASS

[akpm@linux-foundation.org: avoid #defining a CONFIG_ variable]
Signed-off-by: Zhaoxiu Zeng <zhaoxiu.zeng@gmail.com>
Signed-off-by: George Spelvin <linux@horizon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
amery pushed a commit that referenced this issue Nov 18, 2016
When locking a GPIO line as IRQ, we go to lengths to
double-check that the line is really set as input before
marking it as used for IRQ. This is not good on GPIO chips
that can sleep, because this function is called in IRQ-safe
context. Just skip this if it can't be checked quickly.

Currently this happens on sleeping expanders such as STMPE
or TC3589x:

BUG: scheduling while atomic: swapper/1/0x00000002
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.9.0-rc1+ #38
Hardware name: Nomadik STn8815
[<c000f2e0>] (unwind_backtrace) from [<c000d244>] (show_stack+0x10/0x14)
[<c000d244>] (show_stack) from [<c0037b78>] (__schedule_bug+0x54/0x80)
[<c0037b78>] (__schedule_bug) from [<c042df14>] (__schedule+0x3a0/0x460)
[<c042df14>] (__schedule) from [<c042e028>] (schedule+0x54/0xb8)
(...)

This patch fixes that problem and relies on the direction
read from the chip when it was added.

Cc: stable@vger.kernel.org
Fixes: 9c10280 ("gpio: flush direction status in gpiochip_lock_as_irq()")
Cc: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
repojohnray pushed a commit to repojohnray/linux-sunxi-4.7.y that referenced this issue Nov 27, 2016
commit 60f8339 upstream.

When locking a GPIO line as IRQ, we go to lengths to
double-check that the line is really set as input before
marking it as used for IRQ. This is not good on GPIO chips
that can sleep, because this function is called in IRQ-safe
context. Just skip this if it can't be checked quickly.

Currently this happens on sleeping expanders such as STMPE
or TC3589x:

BUG: scheduling while atomic: swapper/1/0x00000002
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.9.0-rc1+ linux-sunxi#38
Hardware name: Nomadik STn8815
[<c000f2e0>] (unwind_backtrace) from [<c000d244>] (show_stack+0x10/0x14)
[<c000d244>] (show_stack) from [<c0037b78>] (__schedule_bug+0x54/0x80)
[<c0037b78>] (__schedule_bug) from [<c042df14>] (__schedule+0x3a0/0x460)
[<c042df14>] (__schedule) from [<c042e028>] (schedule+0x54/0xb8)
(...)

This patch fixes that problem and relies on the direction
read from the chip when it was added.

Fixes: 9c10280 ("gpio: flush direction status in gpiochip_lock_as_irq()")
Cc: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
amery pushed a commit that referenced this issue Apr 1, 2017
[ Upstream commit ecf5fc6 ]

Nikolay has reported a hang when a memcg reclaim got stuck with the
following backtrace:

PID: 18308  TASK: ffff883d7c9b0a30  CPU: 1   COMMAND: "rsync"
  #0 __schedule at ffffffff815ab152
  #1 schedule at ffffffff815ab76e
  #2 schedule_timeout at ffffffff815ae5e5
  #3 io_schedule_timeout at ffffffff815aad6a
  #4 bit_wait_io at ffffffff815abfc6
  #5 __wait_on_bit at ffffffff815abda5
  #6 wait_on_page_bit at ffffffff8111fd4f
  #7 shrink_page_list at ffffffff81135445
  #8 shrink_inactive_list at ffffffff81135845
  #9 shrink_lruvec at ffffffff81135ead
 #10 shrink_zone at ffffffff811360c3
 #11 shrink_zones at ffffffff81136eff
 #12 do_try_to_free_pages at ffffffff8113712f
 #13 try_to_free_mem_cgroup_pages at ffffffff811372be
 #14 try_charge at ffffffff81189423
 #15 mem_cgroup_try_charge at ffffffff8118c6f5
 #16 __add_to_page_cache_locked at ffffffff8112137d
 #17 add_to_page_cache_lru at ffffffff81121618
 #18 pagecache_get_page at ffffffff8112170b
 #19 grow_dev_page at ffffffff811c8297
 #20 __getblk_slow at ffffffff811c91d6
 #21 __getblk_gfp at ffffffff811c92c1
 #22 ext4_ext_grow_indepth at ffffffff8124565c
 #23 ext4_ext_create_new_leaf at ffffffff81246ca8
 #24 ext4_ext_insert_extent at ffffffff81246f09
 #25 ext4_ext_map_blocks at ffffffff8124a848
 #26 ext4_map_blocks at ffffffff8121a5b7
 #27 mpage_map_one_extent at ffffffff8121b1fa
 #28 mpage_map_and_submit_extent at ffffffff8121f07b
 #29 ext4_writepages at ffffffff8121f6d5
 #30 do_writepages at ffffffff8112c490
 #31 __filemap_fdatawrite_range at ffffffff81120199
 #32 filemap_flush at ffffffff8112041c
 #33 ext4_alloc_da_blocks at ffffffff81219da1
 #34 ext4_rename at ffffffff81229b91
 #35 ext4_rename2 at ffffffff81229e32
 #36 vfs_rename at ffffffff811a08a5
 #37 SYSC_renameat2 at ffffffff811a3ffc
 #38 sys_renameat2 at ffffffff811a408e
 #39 sys_rename at ffffffff8119e51e
 #40 system_call_fastpath at ffffffff815afa89

Dave Chinner has properly pointed out that this is a deadlock in the
reclaim code because ext4 doesn't submit pages which are marked by
PG_writeback right away.

The heuristic was introduced by commit e62e384 ("memcg: prevent OOM
with too many dirty pages") and it was applied only when may_enter_fs
was specified.  The code has been changed by c3b94f4 ("memcg:
further prevent OOM with too many dirty pages") which has removed the
__GFP_FS restriction with a reasoning that we do not get into the fs
code.  But this is not sufficient apparently because the fs doesn't
necessarily submit pages marked PG_writeback for IO right away.

ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily
submit the bio.  Instead it tries to map more pages into the bio and
mpage_map_one_extent might trigger memcg charge which might end up
waiting on a page which is marked PG_writeback but hasn't been submitted
yet so we would end up waiting for something that never finishes.

Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2)
before we go to wait on the writeback.  The page fault path, which is
the only path that triggers memcg oom killer since 3.12, shouldn't
require GFP_NOFS and so we shouldn't reintroduce the premature OOM
killer issue which was originally addressed by the heuristic.

As per David Chinner the xfs is doing similar thing since 2.6.15 already
so ext4 is not the only affected filesystem.  Moreover he notes:

: For example: IO completion might require unwritten extent conversion
: which executes filesystem transactions and GFP_NOFS allocations. The
: writeback flag on the pages can not be cleared until unwritten
: extent conversion completes. Hence memory reclaim cannot wait on
: page writeback to complete in GFP_NOFS context because it is not
: safe to do so, memcg reclaim or otherwise.

Cc: stable@vger.kernel.org # 3.9+
[tytso@mit.edu: corrected the control flow]
Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages")
Reported-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
amery pushed a commit that referenced this issue May 26, 2017
qxl_release_map will enter an atomic context, but since we still need to
alloc memory for BOs, we better delay that until we have everything we
need, in case we need to sleep inside the allocation.  This avoids the
Sleep in atomic state below, which was reported by Mike.

 [   43.910362] BUG: sleeping function called from invalid context at mm/slab.h:432
 [   43.910955] in_atomic(): 1, irqs_disabled(): 0, pid: 2077, name: Xorg
 [   43.911472] Preemption disabled at:
 [   43.911478] [<ffffffffa02b1c45>] qxl_bo_kmap_atomic_page+0xa5/0x100 [qxl]
 [   43.912103] CPU: 0 PID: 2077 Comm: Xorg Tainted: G            E   4.12.0-master #38
 [ 43.912550] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
 rel-1.8.1-0-g4adadbd-20161202_174313-build11a 04/01/2014
 [   43.913202] Call Trace:
 [   43.913371]  dump_stack+0x65/0x89
 [   43.913581]  ? qxl_bo_kmap_atomic_page+0xa5/0x100 [qxl]
 [   43.913876]  ___might_sleep+0x11a/0x190
 [   43.914095]  __might_sleep+0x4a/0x80
 [   43.914319]  ? qxl_bo_create+0x50/0x190 [qxl]
 [   43.914565]  kmem_cache_alloc_trace+0x46/0x180
 [   43.914836]  qxl_bo_create+0x50/0x190 [qxl]
 [   43.915082]  ? refcount_dec_and_test+0x11/0x20
 [   43.915332]  ? ttm_mem_io_reserve+0x41/0xe0 [ttm]
 [   43.915595]  qxl_alloc_bo_reserved+0x37/0xb0 [qxl]
 [   43.915884]  qxl_cursor_atomic_update+0x8f/0x260 [qxl]
 [   43.916172]  ? drm_atomic_helper_update_legacy_modeset_state+0x1d6/0x210 [drm_kms_helper]
 [   43.916623]  drm_atomic_helper_commit_planes+0xec/0x230 [drm_kms_helper]
 [   43.916995]  drm_atomic_helper_commit_tail+0x2b/0x60 [drm_kms_helper]
 [   43.917398]  commit_tail+0x65/0x70 [drm_kms_helper]
 [   43.917693]  drm_atomic_helper_commit+0xa9/0x100 [drm_kms_helper]
 [   43.918039]  drm_atomic_commit+0x4b/0x50 [drm]
 [   43.918334]  drm_atomic_helper_update_plane+0xf1/0x110 [drm_kms_helper]
 [   43.918902]  __setplane_internal+0x19f/0x280 [drm]
 [   43.919240]  drm_mode_cursor_universal+0x101/0x1c0 [drm]
 [   43.919541]  drm_mode_cursor_common+0x15b/0x1d0 [drm]
 [   43.919858]  drm_mode_cursor2_ioctl+0xe/0x10 [drm]
 [   43.920157]  drm_ioctl+0x211/0x460 [drm]
 [   43.920383]  ? drm_mode_cursor_ioctl+0x50/0x50 [drm]
 [   43.920664]  ? handle_mm_fault+0x93/0x160
 [   43.920893]  do_vfs_ioctl+0x96/0x6e0
 [   43.921117]  ? __fget+0x73/0xa0
 [   43.921322]  SyS_ioctl+0x41/0x70
 [   43.921545]  entry_SYSCALL_64_fastpath+0x1a/0xa5
 [   43.922188] RIP: 0033:0x7f1145804bc7
 [   43.922526] RSP: 002b:00007ffcd3e50508 EFLAGS: 00003246 ORIG_RAX: 0000000000000010
 [   43.923367] RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 00007f1145804bc7
 [   43.923852] RDX: 00007ffcd3e50540 RSI: 00000000c02464bb RDI: 000000000000000b
 [   43.924299] RBP: 0000000000000040 R08: 0000000000000040 R09: 000000000000000c
 [   43.924694] R10: 00007ffcd3e50340 R11: 0000000000003246 R12: 0000000000000018
 [   43.925128] R13: 00000000022bc390 R14: 0000000000000040 R15: 00007ffcd3e5062c

Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170519175819.15682-1-krisman@collabora.co.uk
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
codekipper pushed a commit to codekipper/linux-sunxi that referenced this issue Jun 26, 2017
Correct these checkpatch.pl errors:

|ERROR: space required before that '-' (ctx:OxO)
|linux-sunxi#37: FILE: include/linux/bug.h:37:
|+#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))

|ERROR: space required before that '-' (ctx:OxO)
|linux-sunxi#38: FILE: include/linux/bug.h:38:
|+#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))

I decided to wrap the bitfield expressions that begin with minus signs
in parentheses rather than insert spaces before the minus signs.

Link: http://lkml.kernel.org/r/20170525120316.24473-5-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
amery pushed a commit that referenced this issue Jul 11, 2017
Correct these checkpatch.pl errors:

|ERROR: space required before that '-' (ctx:OxO)
|#37: FILE: include/linux/bug.h:37:
|+#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))

|ERROR: space required before that '-' (ctx:OxO)
|#38: FILE: include/linux/bug.h:38:
|+#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))

I decided to wrap the bitfield expressions that begin with minus signs
in parentheses rather than insert spaces before the minus signs.

Link: http://lkml.kernel.org/r/20170525120316.24473-5-abbotti@mev.co.uk
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
amery pushed a commit that referenced this issue Mar 6, 2018
pppol2tp_release uses call_rcu to put the final ref on its socket. But
the session object doesn't hold a ref on the session socket so may be
freed while the pppol2tp_put_sk RCU callback is scheduled. Fix this by
having the session hold a ref on its socket until the session is
destroyed. It is this ref that is dropped via call_rcu.

Sessions are also deleted via l2tp_tunnel_closeall. This must now also put
the final ref via call_rcu. So move the call_rcu call site into
pppol2tp_session_close so that this happens in both destroy paths. A
common destroy path should really be implemented, perhaps with
l2tp_tunnel_closeall calling l2tp_session_delete like pppol2tp_release
does, but this will be looked at later.

ODEBUG: activate active (active state 1) object type: rcu_head hint:           (null)
WARNING: CPU: 3 PID: 13407 at lib/debugobjects.c:291 debug_print_object+0x166/0x220
Modules linked in:
CPU: 3 PID: 13407 Comm: syzbot_19c09769 Not tainted 4.16.0-rc2+ #38
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
RIP: 0010:debug_print_object+0x166/0x220
RSP: 0018:ffff880013647a00 EFLAGS: 00010082
RAX: dffffc0000000008 RBX: 0000000000000003 RCX: ffffffff814d3333
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88001a59f6d0
RBP: ffff880013647a40 R08: 0000000000000000 R09: 0000000000000001
R10: ffff8800136479a8 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff86161420 R14: ffffffff85648b60 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88001a580000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020e77000 CR3: 0000000006022000 CR4: 00000000000006e0
Call Trace:
 debug_object_activate+0x38b/0x530
 ? debug_object_assert_init+0x3b0/0x3b0
 ? __mutex_unlock_slowpath+0x85/0x8b0
 ? pppol2tp_session_destruct+0x110/0x110
 __call_rcu.constprop.66+0x39/0x890
 ? __call_rcu.constprop.66+0x39/0x890
 call_rcu_sched+0x17/0x20
 pppol2tp_release+0x2c7/0x440
 ? fcntl_setlk+0xca0/0xca0
 ? sock_alloc_file+0x340/0x340
 sock_release+0x92/0x1e0
 sock_close+0x1b/0x20
 __fput+0x296/0x6e0
 ____fput+0x1a/0x20
 task_work_run+0x127/0x1a0
 do_exit+0x7f9/0x2ce0
 ? SYSC_connect+0x212/0x310
 ? mm_update_next_owner+0x690/0x690
 ? up_read+0x1f/0x40
 ? __do_page_fault+0x3c8/0xca0
 do_group_exit+0x10d/0x330
 ? do_group_exit+0x330/0x330
 SyS_exit_group+0x22/0x30
 do_syscall_64+0x1e0/0x730
 ? trace_hardirqs_off_thunk+0x1a/0x1c
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f362e471259
RSP: 002b:00007ffe389abe08 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f362e471259
RDX: 00007f362e471259 RSI: 000000000000002e RDI: 0000000000000000
RBP: 00007ffe389abe30 R08: 0000000000000000 R09: 00007f362e944270
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400b60
R13: 00007ffe389abf50 R14: 0000000000000000 R15: 0000000000000000
Code: 8d 3c dd a0 8f 64 85 48 89 fa 48 c1 ea 03 80 3c 02 00 75 7b 48 8b 14 dd a0 8f 64 85 4c 89 f6 48 c7 c7 20 85 64 85 e
8 2a 55 14 ff <0f> 0b 83 05 ad 2a 68 04 01 48 83 c4 18 5b 41 5c 41 5d 41 5e 41

Fixes: ee40fb2 ("l2tp: protect sock pointer of struct pppol2tp_session with RCU")
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
amery pushed a commit that referenced this issue May 11, 2018
syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 #32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
wens pushed a commit that referenced this issue May 20, 2018
For some reason, Willem thought that the issue we fixed for TCP
in commit 7ec318f ("tcp: gso: avoid refcount_t warning from
tcp_gso_segment()") was not relevant for UDP GSO.

But syzbot found its way.

refcount_t: saturated; leaking memory.
WARNING: CPU: 0 PID: 10261 at lib/refcount.c:78 refcount_add_not_zero+0x2d4/0x320 lib/refcount.c:78
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 10261 Comm: syz-executor5 Not tainted 4.17.0-rc3+ #38
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 panic+0x22f/0x4de kernel/panic.c:184
 __warn.cold.8+0x163/0x1b3 kernel/panic.c:536
 report_bug+0x252/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x1de/0x490 arch/x86/kernel/traps.c:296
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:992
RIP: 0010:refcount_add_not_zero+0x2d4/0x320 lib/refcount.c:78
RSP: 0018:ffff880196db6b90 EFLAGS: 00010282
RAX: 0000000000000026 RBX: 00000000ffffff01 RCX: ffffc900040d9000
RDX: 0000000000004a29 RSI: ffffffff8160f6f1 RDI: ffff880196db66f0
RBP: ffff880196db6c78 R08: ffff8801b33d6740 R09: 0000000000000002
R10: ffff8801b33d6740 R11: 0000000000000000 R12: 0000000000000000
R13: 00000000ffffffff R14: ffff880196db6c50 R15: 0000000000020101
 refcount_add+0x1b/0x70 lib/refcount.c:102
 __udp_gso_segment+0xaa5/0xee0 net/ipv4/udp_offload.c:272
 udp4_ufo_fragment+0x592/0x7a0 net/ipv4/udp_offload.c:301
 inet_gso_segment+0x639/0x12b0 net/ipv4/af_inet.c:1342
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4050 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3122
 __dev_queue_xmit+0xbf8/0x34c0 net/core/dev.c:3579
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3620
 neigh_direct_output+0x15/0x20 net/core/neighbour.c:1401
 neigh_output include/net/neighbour.h:483 [inline]
 ip_finish_output2+0xa5f/0x1840 net/ipv4/ip_output.c:229
 ip_finish_output+0x828/0xf80 net/ipv4/ip_output.c:317
 NF_HOOK_COND include/linux/netfilter.h:277 [inline]
 ip_output+0x21b/0x850 net/ipv4/ip_output.c:405
 dst_output include/net/dst.h:444 [inline]
 ip_local_out+0xc5/0x1b0 net/ipv4/ip_output.c:124
 ip_send_skb+0x40/0xe0 net/ipv4/ip_output.c:1434
 udp_send_skb.isra.37+0x5eb/0x1000 net/ipv4/udp.c:825
 udp_push_pending_frames+0x5c/0xf0 net/ipv4/udp.c:853
 udp_v6_push_pending_frames+0x380/0x3e0 net/ipv6/udp.c:1105
 udp_lib_setsockopt+0x59a/0x600 net/ipv4/udp.c:2403
 udpv6_setsockopt+0x95/0xa0 net/ipv6/udp.c:1447
 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3046
 __sys_setsockopt+0x1bd/0x390 net/socket.c:1903
 __do_sys_setsockopt net/socket.c:1914 [inline]
 __se_sys_setsockopt net/socket.c:1911 [inline]
 __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1911
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: ad40585 ("udp: better wmem accounting on gso")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
repojohnray pushed a commit to repojohnray/linux-sunxi-4.7.y that referenced this issue May 21, 2018
[ Upstream commit af50e4b ]

syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 jwrdegoede#1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 jwrdegoede#2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 jwrdegoede#3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 jwrdegoede#4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 jwrdegoede#5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 jwrdegoede#6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 linux-sunxi#32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ linux-sunxi#26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
repojohnray pushed a commit to repojohnray/linux-sunxi-4.7.y that referenced this issue May 22, 2018
[ Upstream commit af50e4b ]

syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 jwrdegoede#1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 jwrdegoede#2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 jwrdegoede#3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 jwrdegoede#4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 jwrdegoede#5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 jwrdegoede#6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 jwrdegoede#6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 linux-sunxi#32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 linux-sunxi#47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 linux-sunxi#47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ linux-sunxi#26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
amery pushed a commit that referenced this issue Jun 11, 2018
Configure io_bits with 2 and enable LFS mode, generic/013 reports below dmesg:

BUG: unable to handle kernel NULL pointer dereference at 00000104
*pdpt = 0000000029b7b001 *pde = 0000000000000000
Oops: 0002 [#1] PREEMPT SMP
Modules linked in: crc32_generic zram f2fs(O) rfcomm bnep bluetooth ecdh_generic snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq pcbc joydev snd_seq_device aesni_intel snd_timer aes_i586 snd crypto_simd cryptd soundcore i2c_piix4 serio_raw mac_hid video parport_pc ppdev lp parport hid_generic psmouse usbhid hid e1000
CPU: 0 PID: 11161 Comm: fsstress Tainted: G           O      4.17.0-rc2 #38
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
EIP: f2fs_submit_page_write+0x28d/0x550 [f2fs]
EFLAGS: 00010206 CPU: 0
EAX: e863dcd8 EBX: 00000000 ECX: 00000100 EDX: 00000200
ESI: e863dcf4 EDI: f6f82768 EBP: e863dbb0 ESP: e863db74
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
CR0: 80050033 CR2: 00000104 CR3: 29a62020 CR4: 000406f0
Call Trace:
 do_write_page+0x6f/0xc0 [f2fs]
 write_data_page+0x4a/0xd0 [f2fs]
 do_write_data_page+0x327/0x630 [f2fs]
 __write_data_page+0x34b/0x820 [f2fs]
 __f2fs_write_data_pages+0x42d/0x8c0 [f2fs]
 f2fs_write_data_pages+0x27/0x30 [f2fs]
 do_writepages+0x1a/0x70
 __filemap_fdatawrite_range+0x94/0xd0
 filemap_write_and_wait_range+0x3d/0xa0
 __generic_file_write_iter+0x11a/0x1f0
 f2fs_file_write_iter+0xdd/0x3b0 [f2fs]
 __vfs_write+0xd2/0x150
 vfs_write+0x9b/0x190
 ksys_write+0x45/0x90
 sys_write+0x16/0x20
 do_fast_syscall_32+0xaa/0x22c
 entry_SYSENTER_32+0x4c/0x7b
EIP: 0xb7fc8c51
EFLAGS: 00000246 CPU: 0
EAX: ffffffda EBX: 00000003 ECX: 09cde000 EDX: 00001000
ESI: 00000003 EDI: 00001000 EBP: 00000000 ESP: bfbded38
 DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
Code: e8 f9 77 34 c9 8b 45 e0 8b 80 b8 00 00 00 39 45 d8 0f 84 bb 02 00 00 8b 45 e0 8b 80 b8 00 00 00 8d 50 d8 8b 08 89 55 f0 8b 50 04 <89> 51 04 89 0a c7 00 00 01 00 00 c7 40 04 00 02 00 00 8b 45 dc
EIP: f2fs_submit_page_write+0x28d/0x550 [f2fs] SS:ESP: 0068:e863db74
CR2: 0000000000000104
---[ end trace 4cac79c0d1305ee6 ]---

allocate_data_block will submit all sequential pending IOs sorted by a
FIFO list, If we failed to submit other user's IO due to unaligned write,
we will retry to allocate new block address for current IO, then it will
initialize fio.list again, if fio was in the list before, it can break
FIFO list, result in above panic.

Thread A			Thread B
- do_write_page
 - allocate_data_block
  - list_add_tail
  : fioA cached in FIFO list.
				- do_write_page
				 - allocate_data_block
				  - list_add_tail
				  : fioB cached in FIFO list.
				 - f2fs_submit_page_write
				 : fail to submit IO
				 - allocate_data_block
				  - INIT_LIST_HEAD
 - f2fs_submit_page_write
  - list_del  <-- NULL pointer dereference

This patch adds fio.retry parameter to indicate failure status for each
IO, and avoid bailing out if there is still pending IO in FIFO list for
fixing.

Signed-off-by: Chao Yu <yuchao0@huawei.com>

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
amery pushed a commit that referenced this issue Jun 11, 2018
Configure io_bits with 2 and enable LFS mode, generic/017 reports below dmesg:

BUG: unable to handle kernel NULL pointer dereference at 00000039
*pdpt = 000000002fcb2001 *pde = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: crc32_generic zram f2fs(O) bnep rfcomm bluetooth ecdh_generic snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi pcbc snd_seq joydev aesni_intel aes_i586 snd_seq_device snd_timer crypto_simd cryptd snd soundcore i2c_piix4 serio_raw mac_hid video parport_pc ppdev lp parport hid_generic usbhid psmouse hid e1000
CPU: 2 PID: 20779 Comm: xfs_io Tainted: G           O      4.17.0-rc2 #38
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
EIP: is_checkpointed_data+0x84/0xd0 [f2fs]
EFLAGS: 00010207 CPU: 2
EAX: 00000000 EBX: f5cd7000 ECX: fffffe32 EDX: 00000039
ESI: 000001cd EDI: ec95fb6c EBP: e264bd80 ESP: e264bd6c
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
CR0: 80050033 CR2: 00000039 CR3: 2fe55660 CR4: 000406f0
Call Trace:
 __exchange_data_block+0xb3f/0x1000 [f2fs]
 f2fs_fallocate+0xab9/0x16b0 [f2fs]
 vfs_fallocate+0x17c/0x2d0
 ksys_fallocate+0x42/0x70
 sys_fallocate+0x31/0x40
 do_fast_syscall_32+0xaa/0x22c
 entry_SYSENTER_32+0x4c/0x7b
EIP: 0xb7f98c51
EFLAGS: 00000293 CPU: 2
EAX: ffffffda EBX: 00000003 ECX: 00000008 EDX: 01001000
ESI: 00000000 EDI: 00001000 EBP: 00000000 ESP: bfc0357c
 DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
Code: 00 00 d3 e8 8b 4d ec 2b 02 8b 55 f0 6b c0 1c 03 41 70 29 d6 8b 93 d0 06 00 00 8b 40 0c 83 ea 01 21 d6 89 f2 89 f1 c1 ea 03 f7 d1 <0f> be 14 10 83 e1 07 b8 01 00 00 00 d3 e0 85 c2 89 f8 0f 95 c3
EIP: is_checkpointed_data+0x84/0xd0 [f2fs] SS:ESP: 0068:e264bd6c
CR2: 0000000000000039
---[ end trace 9a4d4087cce6080a ]---

This is because in recovery flow of __exchange_data_block, we didn't pass olen to
__roll_back_blkaddrs, instead we passed len, which indicates wrong array size, result
in copying random block address into dnode page.

Later, once that random block address was accessed by is_checkpointed_data, it can
cause NULL pointer dereference.

Signed-off-by: Chao Yu <yuchao0@huawei.com>

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
amery pushed a commit that referenced this issue Jul 31, 2018
Configure io_bits with 2 and enable LFS mode, generic/013 reports below dmesg:

BUG: unable to handle kernel NULL pointer dereference at 00000104
*pdpt = 0000000029b7b001 *pde = 0000000000000000
Oops: 0002 [#1] PREEMPT SMP
Modules linked in: crc32_generic zram f2fs(O) rfcomm bnep bluetooth ecdh_generic snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq pcbc joydev snd_seq_device aesni_intel snd_timer aes_i586 snd crypto_simd cryptd soundcore i2c_piix4 serio_raw mac_hid video parport_pc ppdev lp parport hid_generic psmouse usbhid hid e1000
CPU: 0 PID: 11161 Comm: fsstress Tainted: G           O      4.17.0-rc2 #38
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
EIP: f2fs_submit_page_write+0x28d/0x550 [f2fs]
EFLAGS: 00010206 CPU: 0
EAX: e863dcd8 EBX: 00000000 ECX: 00000100 EDX: 00000200
ESI: e863dcf4 EDI: f6f82768 EBP: e863dbb0 ESP: e863db74
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
CR0: 80050033 CR2: 00000104 CR3: 29a62020 CR4: 000406f0
Call Trace:
 do_write_page+0x6f/0xc0 [f2fs]
 write_data_page+0x4a/0xd0 [f2fs]
 do_write_data_page+0x327/0x630 [f2fs]
 __write_data_page+0x34b/0x820 [f2fs]
 __f2fs_write_data_pages+0x42d/0x8c0 [f2fs]
 f2fs_write_data_pages+0x27/0x30 [f2fs]
 do_writepages+0x1a/0x70
 __filemap_fdatawrite_range+0x94/0xd0
 filemap_write_and_wait_range+0x3d/0xa0
 __generic_file_write_iter+0x11a/0x1f0
 f2fs_file_write_iter+0xdd/0x3b0 [f2fs]
 __vfs_write+0xd2/0x150
 vfs_write+0x9b/0x190
 ksys_write+0x45/0x90
 sys_write+0x16/0x20
 do_fast_syscall_32+0xaa/0x22c
 entry_SYSENTER_32+0x4c/0x7b
EIP: 0xb7fc8c51
EFLAGS: 00000246 CPU: 0
EAX: ffffffda EBX: 00000003 ECX: 09cde000 EDX: 00001000
ESI: 00000003 EDI: 00001000 EBP: 00000000 ESP: bfbded38
 DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
Code: e8 f9 77 34 c9 8b 45 e0 8b 80 b8 00 00 00 39 45 d8 0f 84 bb 02 00 00 8b 45 e0 8b 80 b8 00 00 00 8d 50 d8 8b 08 89 55 f0 8b 50 04 <89> 51 04 89 0a c7 00 00 01 00 00 c7 40 04 00 02 00 00 8b 45 dc
EIP: f2fs_submit_page_write+0x28d/0x550 [f2fs] SS:ESP: 0068:e863db74
CR2: 0000000000000104
---[ end trace 4cac79c0d1305ee6 ]---

allocate_data_block will submit all sequential pending IOs sorted by a
FIFO list, If we failed to submit other user's IO due to unaligned write,
we will retry to allocate new block address for current IO, then it will
initialize fio.list again, if fio was in the list before, it can break
FIFO list, result in above panic.

Thread A			Thread B
- do_write_page
 - allocate_data_block
  - list_add_tail
  : fioA cached in FIFO list.
				- do_write_page
				 - allocate_data_block
				  - list_add_tail
				  : fioB cached in FIFO list.
				 - f2fs_submit_page_write
				 : fail to submit IO
				 - allocate_data_block
				  - INIT_LIST_HEAD
 - f2fs_submit_page_write
  - list_del  <-- NULL pointer dereference

This patch adds fio.retry parameter to indicate failure status for each
IO, and avoid bailing out if there is still pending IO in FIFO list for
fixing.

Signed-off-by: Chao Yu <yuchao0@huawei.com>

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
amery pushed a commit that referenced this issue Jul 31, 2018
Configure io_bits with 2 and enable LFS mode, generic/017 reports below dmesg:

BUG: unable to handle kernel NULL pointer dereference at 00000039
*pdpt = 000000002fcb2001 *pde = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: crc32_generic zram f2fs(O) bnep rfcomm bluetooth ecdh_generic snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi pcbc snd_seq joydev aesni_intel aes_i586 snd_seq_device snd_timer crypto_simd cryptd snd soundcore i2c_piix4 serio_raw mac_hid video parport_pc ppdev lp parport hid_generic usbhid psmouse hid e1000
CPU: 2 PID: 20779 Comm: xfs_io Tainted: G           O      4.17.0-rc2 #38
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
EIP: is_checkpointed_data+0x84/0xd0 [f2fs]
EFLAGS: 00010207 CPU: 2
EAX: 00000000 EBX: f5cd7000 ECX: fffffe32 EDX: 00000039
ESI: 000001cd EDI: ec95fb6c EBP: e264bd80 ESP: e264bd6c
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
CR0: 80050033 CR2: 00000039 CR3: 2fe55660 CR4: 000406f0
Call Trace:
 __exchange_data_block+0xb3f/0x1000 [f2fs]
 f2fs_fallocate+0xab9/0x16b0 [f2fs]
 vfs_fallocate+0x17c/0x2d0
 ksys_fallocate+0x42/0x70
 sys_fallocate+0x31/0x40
 do_fast_syscall_32+0xaa/0x22c
 entry_SYSENTER_32+0x4c/0x7b
EIP: 0xb7f98c51
EFLAGS: 00000293 CPU: 2
EAX: ffffffda EBX: 00000003 ECX: 00000008 EDX: 01001000
ESI: 00000000 EDI: 00001000 EBP: 00000000 ESP: bfc0357c
 DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
Code: 00 00 d3 e8 8b 4d ec 2b 02 8b 55 f0 6b c0 1c 03 41 70 29 d6 8b 93 d0 06 00 00 8b 40 0c 83 ea 01 21 d6 89 f2 89 f1 c1 ea 03 f7 d1 <0f> be 14 10 83 e1 07 b8 01 00 00 00 d3 e0 85 c2 89 f8 0f 95 c3
EIP: is_checkpointed_data+0x84/0xd0 [f2fs] SS:ESP: 0068:e264bd6c
CR2: 0000000000000039
---[ end trace 9a4d4087cce6080a ]---

This is because in recovery flow of __exchange_data_block, we didn't pass olen to
__roll_back_blkaddrs, instead we passed len, which indicates wrong array size, result
in copying random block address into dnode page.

Later, once that random block address was accessed by is_checkpointed_data, it can
cause NULL pointer dereference.

Signed-off-by: Chao Yu <yuchao0@huawei.com>

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
amery pushed a commit that referenced this issue Oct 23, 2018
Please note that below oops is from an older kernel, but the same
race seems to be present in the upstream kernel too.

---8<---

The following panic was encountered during removing the ipmi_ssif
module:

[ 526.352555] Unable to handle kernel paging request at virtual address ffff000006923090
[ 526.360464] Mem abort info:
[ 526.363257] ESR = 0x86000007
[ 526.366304] Exception class = IABT (current EL), IL = 32 bits
[ 526.372221] SET = 0, FnV = 0
[ 526.375269] EA = 0, S1PTW = 0
[ 526.378405] swapper pgtable: 4k pages, 48-bit VAs, pgd = 000000008ae60416
[ 526.385185] [ffff000006923090] *pgd=000000bffcffe803, *pud=000000bffcffd803, *pmd=0000009f4731a003, *pte=0000000000000000
[ 526.396141] Internal error: Oops: 86000007 [#1] SMP
[ 526.401008] Modules linked in: nls_iso8859_1 ipmi_devintf joydev input_leds ipmi_msghandler shpchp sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear i2c_smbus hid_generic usbhid uas hid usb_storage ast aes_ce_blk i2c_algo_bit aes_ce_cipher qede ttm crc32_ce ptp crct10dif_ce drm_kms_helper ghash_ce syscopyarea sha2_ce sysfillrect sysimgblt pps_core fb_sys_fops sha256_arm64 sha1_ce mpt3sas qed drm raid_class ahci scsi_transport_sas libahci gpio_xlp i2c_xlp9xx aes_neon_bs aes_neon_blk crypto_simd cryptd aes_arm64 [last unloaded: ipmi_ssif]
[ 526.468085] CPU: 125 PID: 0 Comm: swapper/125 Not tainted 4.15.0-35-generic #38~lp1775396+build.1
[ 526.476942] Hardware name: To be filled by O.E.M. Saber/Saber, BIOS 0ACKL022 08/14/2018
[ 526.484932] pstate: 00400009 (nzcv daif +PAN -UAO)
[ 526.489713] pc : 0xffff000006923090
[ 526.493198] lr : call_timer_fn+0x34/0x178
[ 526.497194] sp : ffff000009b0bdd0
[ 526.500496] x29: ffff000009b0bdd0 x28: 0000000000000082
[ 526.505796] x27: 0000000000000002 x26: ffff000009515188
[ 526.511096] x25: ffff000009515180 x24: ffff0000090f1018
[ 526.516396] x23: ffff000009519660 x22: dead000000000200
[ 526.521696] x21: ffff000006923090 x20: 0000000000000100
[ 526.526995] x19: ffff809eeb466a40 x18: 0000000000000000
[ 526.532295] x17: 000000000000000e x16: 0000000000000007
[ 526.537594] x15: 0000000000000000 x14: 071c71c71c71c71c
[ 526.542894] x13: 0000000000000000 x12: 0000000000000000
[ 526.548193] x11: 0000000000000001 x10: ffff000009b0be88
[ 526.553493] x9 : 0000000000000000 x8 : 0000000000000005
[ 526.558793] x7 : ffff80befc1f8528 x6 : 0000000000000020
[ 526.564092] x5 : 0000000000000040 x4 : 0000000020001b20
[ 526.569392] x3 : 0000000000000000 x2 : ffff809eeb466a40
[ 526.574692] x1 : ffff000006923090 x0 : ffff809eeb466a40
[ 526.579992] Process swapper/125 (pid: 0, stack limit = 0x000000002eb50acc)
[ 526.586854] Call trace:
[ 526.589289] 0xffff000006923090
[ 526.592419] expire_timers+0xc8/0x130
[ 526.596070] run_timer_softirq+0xec/0x1b0
[ 526.600070] __do_softirq+0x134/0x328
[ 526.603726] irq_exit+0xc8/0xe0
[ 526.606857] __handle_domain_irq+0x6c/0xc0
[ 526.610941] gic_handle_irq+0x84/0x188
[ 526.614679] el1_irq+0xe8/0x180
[ 526.617822] cpuidle_enter_state+0xa0/0x328
[ 526.621993] cpuidle_enter+0x34/0x48
[ 526.625564] call_cpuidle+0x44/0x70
[ 526.629040] do_idle+0x1b8/0x1f0
[ 526.632256] cpu_startup_entry+0x2c/0x30
[ 526.636174] secondary_start_kernel+0x11c/0x130
[ 526.640694] Code: bad PC value
[ 526.643800] ---[ end trace d020b0b8417c2498 ]---
[ 526.648404] Kernel panic - not syncing: Fatal exception in interrupt
[ 526.654778] SMP: stopping secondary CPUs
[ 526.658734] Kernel Offset: disabled
[ 526.662211] CPU features: 0x5800c38
[ 526.665688] Memory Limit: none
[ 526.668768] ---[ end Kernel panic - not syncing: Fatal exception in interrupt

Prevent mod_timer from arming a timer that was already removed by
del_timer during module unload.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Cc: <stable@vger.kernel.org> # 3.19
Signed-off-by: Corey Minyard <cminyard@mvista.com>
amery pushed a commit that referenced this issue Nov 9, 2018
Increase kasan instrumented kernel stack size from 32k to 64k. Other
architectures seems to get away with just doubling kernel stack size under
kasan, but on s390 this appears to be not enough due to bigger frame size.
The particular pain point is kasan inlined checks (CONFIG_KASAN_INLINE
vs CONFIG_KASAN_OUTLINE). With inlined checks one particular case hitting
stack overflow is fs sync on xfs filesystem:

 #0 [9a0681e8]  704 bytes  check_usage at 34b1fc
 #1 [9a0684a8]  432 bytes  check_usage at 34c710
 #2 [9a068658]  1048 bytes  validate_chain at 35044a
 #3 [9a068a70]  312 bytes  __lock_acquire at 3559fe
 #4 [9a068ba8]  440 bytes  lock_acquire at 3576ee
 #5 [9a068d60]  104 bytes  _raw_spin_lock at 21b44e0
 #6 [9a068dc8]  1992 bytes  enqueue_entity at 2dbf72
 #7 [9a069590]  1496 bytes  enqueue_task_fair at 2df5f0
 #8 [9a069b68]  64 bytes  ttwu_do_activate at 28f438
 #9 [9a069ba8]  552 bytes  try_to_wake_up at 298c4c
 #10 [9a069dd0]  168 bytes  wake_up_worker at 23f97c
 #11 [9a069e78]  200 bytes  insert_work at 23fc2e
 #12 [9a069f40]  648 bytes  __queue_work at 2487c0
 #13 [9a06a1c8]  200 bytes  __queue_delayed_work at 24db28
 #14 [9a06a290]  248 bytes  mod_delayed_work_on at 24de84
 #15 [9a06a388]  24 bytes  kblockd_mod_delayed_work_on at 153e2a0
 #16 [9a06a3a0]  288 bytes  __blk_mq_delay_run_hw_queue at 158168c
 #17 [9a06a4c0]  192 bytes  blk_mq_run_hw_queue at 1581a3c
 #18 [9a06a580]  184 bytes  blk_mq_sched_insert_requests at 15a2192
 #19 [9a06a638]  1024 bytes  blk_mq_flush_plug_list at 1590f3a
 #20 [9a06aa38]  704 bytes  blk_flush_plug_list at 1555028
 #21 [9a06acf8]  320 bytes  schedule at 219e476
 #22 [9a06ae38]  760 bytes  schedule_timeout at 21b0aac
 #23 [9a06b130]  408 bytes  wait_for_common at 21a1706
 #24 [9a06b2c8]  360 bytes  xfs_buf_iowait at fa1540
 #25 [9a06b430]  256 bytes  __xfs_buf_submit at fadae6
 #26 [9a06b530]  264 bytes  xfs_buf_read_map at fae3f6
 #27 [9a06b638]  656 bytes  xfs_trans_read_buf_map at 10ac9a8
 #28 [9a06b8c8]  304 bytes  xfs_btree_kill_root at e72426
 #29 [9a06b9f8]  288 bytes  xfs_btree_lookup_get_block at e7bc5e
 #30 [9a06bb18]  624 bytes  xfs_btree_lookup at e7e1a6
 #31 [9a06bd88]  2664 bytes  xfs_alloc_ag_vextent_near at dfa070
 #32 [9a06c7f0]  144 bytes  xfs_alloc_ag_vextent at dff3ca
 #33 [9a06c880]  1128 bytes  xfs_alloc_vextent at e05fce
 #34 [9a06cce8]  584 bytes  xfs_bmap_btalloc at e58342
 #35 [9a06cf30]  1336 bytes  xfs_bmapi_write at e618de
 #36 [9a06d468]  776 bytes  xfs_iomap_write_allocate at ff678e
 #37 [9a06d770]  720 bytes  xfs_map_blocks at f82af8
 #38 [9a06da40]  928 bytes  xfs_writepage_map at f83cd6
 #39 [9a06dde0]  320 bytes  xfs_do_writepage at f85872
 #40 [9a06df20]  1320 bytes  write_cache_pages at 73dfe8
 #41 [9a06e448]  208 bytes  xfs_vm_writepages at f7f892
 #42 [9a06e518]  88 bytes  do_writepages at 73fe6a
 #43 [9a06e570]  872 bytes  __writeback_single_inode at a20cb6
 #44 [9a06e8d8]  664 bytes  writeback_sb_inodes at a23be2
 #45 [9a06eb70]  296 bytes  __writeback_inodes_wb at a242e0
 #46 [9a06ec98]  928 bytes  wb_writeback at a2500e
 #47 [9a06f038]  848 bytes  wb_do_writeback at a260ae
 #48 [9a06f388]  536 bytes  wb_workfn at a28228
 #49 [9a06f5a0]  1088 bytes  process_one_work at 24a234
 #50 [9a06f9e0]  1120 bytes  worker_thread at 24ba26
 #51 [9a06fe40]  104 bytes  kthread at 26545a
 #52 [9a06fea8]             kernel_thread_starter at 21b6b62

To be able to increase the stack size to 64k reuse LLILL instruction
in __switch_to function to load 64k - STACK_FRAME_OVERHEAD - __PT_SIZE
(65192) value as unsigned.

Reported-by: Benjamin Block <bblock@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
repojohnray pushed a commit to repojohnray/linux-sunxi-4.7.y that referenced this issue Nov 13, 2018
commit 0711e8c upstream.

Please note that below oops is from an older kernel, but the same
race seems to be present in the upstream kernel too.

---8<---

The following panic was encountered during removing the ipmi_ssif
module:

[ 526.352555] Unable to handle kernel paging request at virtual address ffff000006923090
[ 526.360464] Mem abort info:
[ 526.363257] ESR = 0x86000007
[ 526.366304] Exception class = IABT (current EL), IL = 32 bits
[ 526.372221] SET = 0, FnV = 0
[ 526.375269] EA = 0, S1PTW = 0
[ 526.378405] swapper pgtable: 4k pages, 48-bit VAs, pgd = 000000008ae60416
[ 526.385185] [ffff000006923090] *pgd=000000bffcffe803, *pud=000000bffcffd803, *pmd=0000009f4731a003, *pte=0000000000000000
[ 526.396141] Internal error: Oops: 86000007 [jwrdegoede#1] SMP
[ 526.401008] Modules linked in: nls_iso8859_1 ipmi_devintf joydev input_leds ipmi_msghandler shpchp sch_fq_codel ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables x_tables autofs4 btrfs zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear i2c_smbus hid_generic usbhid uas hid usb_storage ast aes_ce_blk i2c_algo_bit aes_ce_cipher qede ttm crc32_ce ptp crct10dif_ce drm_kms_helper ghash_ce syscopyarea sha2_ce sysfillrect sysimgblt pps_core fb_sys_fops sha256_arm64 sha1_ce mpt3sas qed drm raid_class ahci scsi_transport_sas libahci gpio_xlp i2c_xlp9xx aes_neon_bs aes_neon_blk crypto_simd cryptd aes_arm64 [last unloaded: ipmi_ssif]
[ 526.468085] CPU: 125 PID: 0 Comm: swapper/125 Not tainted 4.15.0-35-generic linux-sunxi#38~lp1775396+build.1
[ 526.476942] Hardware name: To be filled by O.E.M. Saber/Saber, BIOS 0ACKL022 08/14/2018
[ 526.484932] pstate: 00400009 (nzcv daif +PAN -UAO)
[ 526.489713] pc : 0xffff000006923090
[ 526.493198] lr : call_timer_fn+0x34/0x178
[ 526.497194] sp : ffff000009b0bdd0
[ 526.500496] x29: ffff000009b0bdd0 x28: 0000000000000082
[ 526.505796] x27: 0000000000000002 x26: ffff000009515188
[ 526.511096] x25: ffff000009515180 x24: ffff0000090f1018
[ 526.516396] x23: ffff000009519660 x22: dead000000000200
[ 526.521696] x21: ffff000006923090 x20: 0000000000000100
[ 526.526995] x19: ffff809eeb466a40 x18: 0000000000000000
[ 526.532295] x17: 000000000000000e x16: 0000000000000007
[ 526.537594] x15: 0000000000000000 x14: 071c71c71c71c71c
[ 526.542894] x13: 0000000000000000 x12: 0000000000000000
[ 526.548193] x11: 0000000000000001 x10: ffff000009b0be88
[ 526.553493] x9 : 0000000000000000 x8 : 0000000000000005
[ 526.558793] x7 : ffff80befc1f8528 x6 : 0000000000000020
[ 526.564092] x5 : 0000000000000040 x4 : 0000000020001b20
[ 526.569392] x3 : 0000000000000000 x2 : ffff809eeb466a40
[ 526.574692] x1 : ffff000006923090 x0 : ffff809eeb466a40
[ 526.579992] Process swapper/125 (pid: 0, stack limit = 0x000000002eb50acc)
[ 526.586854] Call trace:
[ 526.589289] 0xffff000006923090
[ 526.592419] expire_timers+0xc8/0x130
[ 526.596070] run_timer_softirq+0xec/0x1b0
[ 526.600070] __do_softirq+0x134/0x328
[ 526.603726] irq_exit+0xc8/0xe0
[ 526.606857] __handle_domain_irq+0x6c/0xc0
[ 526.610941] gic_handle_irq+0x84/0x188
[ 526.614679] el1_irq+0xe8/0x180
[ 526.617822] cpuidle_enter_state+0xa0/0x328
[ 526.621993] cpuidle_enter+0x34/0x48
[ 526.625564] call_cpuidle+0x44/0x70
[ 526.629040] do_idle+0x1b8/0x1f0
[ 526.632256] cpu_startup_entry+0x2c/0x30
[ 526.636174] secondary_start_kernel+0x11c/0x130
[ 526.640694] Code: bad PC value
[ 526.643800] ---[ end trace d020b0b8417c2498 ]---
[ 526.648404] Kernel panic - not syncing: Fatal exception in interrupt
[ 526.654778] SMP: stopping secondary CPUs
[ 526.658734] Kernel Offset: disabled
[ 526.662211] CPU features: 0x5800c38
[ 526.665688] Memory Limit: none
[ 526.668768] ---[ end Kernel panic - not syncing: Fatal exception in interrupt

Prevent mod_timer from arming a timer that was already removed by
del_timer during module unload.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
Cc: <stable@vger.kernel.org> # 3.19
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jwrdegoede pushed a commit to jwrdegoede/linux-sunxi that referenced this issue Oct 28, 2019
Connecting a vCPU to a XIVE KVM device means establishing a 1:1
association between a vCPU id and the offset (VP id) of a VP
structure within a fixed size block of VPs. We currently try to
enforce the 1:1 relationship by checking that a vCPU with the
same id isn't already connected. This is good but unfortunately
not enough because we don't map VP ids to raw vCPU ids but to
packed vCPU ids, and the packing function kvmppc_pack_vcpu_id()
isn't bijective by design. We got away with it because QEMU passes
vCPU ids that fit well in the packing pattern. But nothing prevents
userspace to come up with a forged vCPU id resulting in a packed id
collision which causes the KVM device to associate two vCPUs to the
same VP. This greatly confuses the irq layer and ultimately crashes
the kernel, as shown below.

Example: a guest with 1 guest thread per core, a core stride of
8 and 300 vCPUs has vCPU ids 0,8,16...2392. If QEMU is patched to
inject at some point an invalid vCPU id 348, which is the packed
version of itself and 2392, we get:

genirq: Flags mismatch irq 199. 00010000 (kvm-2-2392) vs. 00010000 (kvm-2-348)
CPU: 24 PID: 88176 Comm: qemu-system-ppc Not tainted 5.3.0-xive-nr-servers-5.3-gku+ linux-sunxi#38
Call Trace:
[c000003f7f9937e0] [c000000000c0110c] dump_stack+0xb0/0xf4 (unreliable)
[c000003f7f993820] [c0000000001cb480] __setup_irq+0xa70/0xad0
[c000003f7f9938d0] [c0000000001cb75c] request_threaded_irq+0x13c/0x260
[c000003f7f993940] [c00800000d44e7ac] kvmppc_xive_attach_escalation+0x104/0x270 [kvm]
[c000003f7f9939d0] [c00800000d45013c] kvmppc_xive_connect_vcpu+0x424/0x620 [kvm]
[c000003f7f993ac0] [c00800000d444428] kvm_arch_vcpu_ioctl+0x260/0x448 [kvm]
[c000003f7f993b90] [c00800000d43593c] kvm_vcpu_ioctl+0x154/0x7c8 [kvm]
[c000003f7f993d00] [c0000000004840f0] do_vfs_ioctl+0xe0/0xc30
[c000003f7f993db0] [c000000000484d44] ksys_ioctl+0x104/0x120
[c000003f7f993e00] [c000000000484d88] sys_ioctl+0x28/0x80
[c000003f7f993e20] [c00000000000b278] system_call+0x5c/0x68
xive-kvm: Failed to request escalation interrupt for queue 0 of VCPU 2392
------------[ cut here ]------------
remove_proc_entry: removing non-empty directory 'irq/199', leaking at least 'kvm-2-348'
WARNING: CPU: 24 PID: 88176 at /home/greg/Work/linux/kernel-kvm-ppc/fs/proc/generic.c:684 remove_proc_entry+0x1ec/0x200
Modules linked in: kvm_hv kvm dm_mod vhost_net vhost tap xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter squashfs loop fuse i2c_dev sg ofpart ocxl powernv_flash at24 xts mtd uio_pdrv_genirq vmx_crypto opal_prd ipmi_powernv uio ipmi_devintf ipmi_msghandler ibmpowernv ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables ext4 mbcache jbd2 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq libcrc32c raid1 raid0 linear sd_mod ast i2c_algo_bit drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci libahci libata tg3 drm_panel_orientation_quirks [last unloaded: kvm]
CPU: 24 PID: 88176 Comm: qemu-system-ppc Not tainted 5.3.0-xive-nr-servers-5.3-gku+ linux-sunxi#38
NIP:  c00000000053b0cc LR: c00000000053b0c8 CTR: c0000000000ba3b0
REGS: c000003f7f9934b0 TRAP: 0700   Not tainted  (5.3.0-xive-nr-servers-5.3-gku+)
MSR:  9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 48228222  XER: 20040000
CFAR: c000000000131a50 IRQMASK: 0
GPR00: c00000000053b0c8 c000003f7f993740 c0000000015ec500 0000000000000057
GPR04: 0000000000000001 0000000000000000 000049fb98484262 0000000000001bcf
GPR08: 0000000000000007 0000000000000007 0000000000000001 9000000000001033
GPR12: 0000000000008000 c000003ffffeb800 0000000000000000 000000012f4ce5a1
GPR16: 000000012ef5a0c8 0000000000000000 000000012f113bb0 0000000000000000
GPR20: 000000012f45d918 c000003f863758b0 c000003f86375870 0000000000000006
GPR24: c000003f86375a30 0000000000000007 c0002039373d9020 c0000000014c4a48
GPR28: 0000000000000001 c000003fe62a4f6b c00020394b2e9fab c000003fe62a4ec0
NIP [c00000000053b0cc] remove_proc_entry+0x1ec/0x200
LR [c00000000053b0c8] remove_proc_entry+0x1e8/0x200
Call Trace:
[c000003f7f993740] [c00000000053b0c8] remove_proc_entry+0x1e8/0x200 (unreliable)
[c000003f7f9937e0] [c0000000001d3654] unregister_irq_proc+0x114/0x150
[c000003f7f993880] [c0000000001c6284] free_desc+0x54/0xb0
[c000003f7f9938c0] [c0000000001c65ec] irq_free_descs+0xac/0x100
[c000003f7f993910] [c0000000001d1ff8] irq_dispose_mapping+0x68/0x80
[c000003f7f993940] [c00800000d44e8a4] kvmppc_xive_attach_escalation+0x1fc/0x270 [kvm]
[c000003f7f9939d0] [c00800000d45013c] kvmppc_xive_connect_vcpu+0x424/0x620 [kvm]
[c000003f7f993ac0] [c00800000d444428] kvm_arch_vcpu_ioctl+0x260/0x448 [kvm]
[c000003f7f993b90] [c00800000d43593c] kvm_vcpu_ioctl+0x154/0x7c8 [kvm]
[c000003f7f993d00] [c0000000004840f0] do_vfs_ioctl+0xe0/0xc30
[c000003f7f993db0] [c000000000484d44] ksys_ioctl+0x104/0x120
[c000003f7f993e00] [c000000000484d88] sys_ioctl+0x28/0x80
[c000003f7f993e20] [c00000000000b278] system_call+0x5c/0x68
Instruction dump:
2c230000 41820008 3923ff78 e8e900a0 3c82ff69 3c62ff8d 7fa6eb78 7fc5f378
3884f080 3863b948 4bbf6925 60000000 <0fe00000> 4bffff7c fba10088 4bbf6e41
---[ end trace b925b67a74a1d8d1 ]---
BUG: Kernel NULL pointer dereference at 0x00000010
Faulting instruction address: 0xc00800000d44fc04
Oops: Kernel access of bad area, sig: 11 [#1]
LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=2048 NUMA PowerNV
Modules linked in: kvm_hv kvm dm_mod vhost_net vhost tap xt_CHECKSUM iptable_mangle xt_MASQUERADE iptable_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter squashfs loop fuse i2c_dev sg ofpart ocxl powernv_flash at24 xts mtd uio_pdrv_genirq vmx_crypto opal_prd ipmi_powernv uio ipmi_devintf ipmi_msghandler ibmpowernv ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ip_tables ext4 mbcache jbd2 raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq libcrc32c raid1 raid0 linear sd_mod ast i2c_algo_bit drm_vram_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ahci libahci libata tg3 drm_panel_orientation_quirks [last unloaded: kvm]
CPU: 24 PID: 88176 Comm: qemu-system-ppc Tainted: G        W         5.3.0-xive-nr-servers-5.3-gku+ linux-sunxi#38
NIP:  c00800000d44fc04 LR: c00800000d44fc00 CTR: c0000000001cd970
REGS: c000003f7f9938e0 TRAP: 0300   Tainted: G        W          (5.3.0-xive-nr-servers-5.3-gku+)
MSR:  9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 24228882  XER: 20040000
CFAR: c0000000001cd9ac DAR: 0000000000000010 DSISR: 40000000 IRQMASK: 0
GPR00: c00800000d44fc00 c000003f7f993b70 c00800000d468300 0000000000000000
GPR04: 00000000000000c7 0000000000000000 0000000000000000 c000003ffacd06d8
GPR08: 0000000000000000 c000003ffacd0738 0000000000000000 fffffffffffffffd
GPR12: 0000000000000040 c000003ffffeb800 0000000000000000 000000012f4ce5a1
GPR16: 000000012ef5a0c8 0000000000000000 000000012f113bb0 0000000000000000
GPR20: 000000012f45d918 00007ffffe0d9a80 000000012f4f5df0 000000012ef8c9f8
GPR24: 0000000000000001 0000000000000000 c000003fe4501ed0 c000003f8b1d0000
GPR28: c0000033314689c0 c000003fe4501c00 c000003fe4501e70 c000003fe4501e90
NIP [c00800000d44fc04] kvmppc_xive_cleanup_vcpu+0xfc/0x210 [kvm]
LR [c00800000d44fc00] kvmppc_xive_cleanup_vcpu+0xf8/0x210 [kvm]
Call Trace:
[c000003f7f993b70] [c00800000d44fc00] kvmppc_xive_cleanup_vcpu+0xf8/0x210 [kvm] (unreliable)
[c000003f7f993bd0] [c00800000d450bd4] kvmppc_xive_release+0xdc/0x1b0 [kvm]
[c000003f7f993c30] [c00800000d436a98] kvm_device_release+0xb0/0x110 [kvm]
[c000003f7f993c70] [c00000000046730c] __fput+0xec/0x320
[c000003f7f993cd0] [c000000000164ae0] task_work_run+0x150/0x1c0
[c000003f7f993d30] [c000000000025034] do_notify_resume+0x304/0x440
[c000003f7f993e20] [c00000000000dcc4] ret_from_except_lite+0x70/0x74
Instruction dump:
3bff0008 7fbfd040 419e0054 847e0004 2fa30000 419effec e93d0000 8929203c
2f890000 419effb8 4800821d e8410018 <e9230010> e9490008 9b2a0039 7c0004ac
---[ end trace b925b67a74a1d8d2 ]---

Kernel panic - not syncing: Fatal exception

This affects both XIVE and XICS-on-XIVE devices since the beginning.

Check the VP id instead of the vCPU id when a new vCPU is connected.
The allocation of the XIVE CPU structure in kvmppc_xive_connect_vcpu()
is moved after the check to avoid the need for rollback.

Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
jwrdegoede added a commit to jwrdegoede/linux-sunxi that referenced this issue Sep 14, 2020
Commit cc81696 ("serial: 8250_dw: Fix common clocks usage race condition")
causes the following lockdep warning:

[  843.852886] ======================================================
[  843.852888] WARNING: possible circular locking dependency detected
[  843.852894] 5.9.0-rc3+ linux-sunxi#38 Tainted: G        W   E
[  843.852896] ------------------------------------------------------
[  843.852900] systemd-sleep/1628 is trying to acquire lock:
[  843.852905] ffff935e30344d80 ((work_completion)(&data->clk_work)){+.+.}-{0:0}, at: __flush_work+0x2e6/0x460
[  843.852922]
               but task is already holding lock:
[  843.852924] ffff935e302f1420 (&port->mutex){+.+.}-{3:3}, at: uart_suspend_port+0x3f/0x1f0
[  843.852938]
               which lock already depends on the new lock.

[  843.852940]
               the existing dependency chain (in reverse order) is:
[  843.852943]
               -> #1 (&port->mutex){+.+.}-{3:3}:
[  843.852954]        __mutex_lock+0x7b/0x820
[  843.852959]        serial8250_update_uartclk+0x34/0x1b0
[  843.852965]        process_one_work+0x23f/0x570
[  843.852969]        worker_thread+0x55/0x3c0
[  843.852974]        kthread+0x138/0x160
[  843.852981]        ret_from_fork+0x22/0x30
[  843.852984]
               -> #0 ((work_completion)(&data->clk_work)){+.+.}-{0:0}:
[  843.852995]        __lock_acquire+0x1238/0x2080
[  843.852999]        lock_acquire+0xa7/0x3d0
[  843.853003]        __flush_work+0x30d/0x460
[  843.853008]        uart_suspend_port+0x1b9/0x1f0
[  843.853014]        dw8250_suspend+0x10/0x20
[  843.853020]        dpm_run_callback+0x51/0xc0
[  843.853025]        __device_suspend+0x1f9/0x450
[  843.853029]        dpm_suspend+0x13d/0x1e0
[  843.853033]        dpm_suspend_start+0x77/0x80
[  843.853040]        suspend_devices_and_enter+0xe6/0x620
[  843.853044]        pm_suspend.cold+0x333/0x389
[  843.853048]        state_store+0x71/0xd0
[  843.853056]        kernfs_fop_write+0xdc/0x1c0
[  843.853063]        vfs_write+0xec/0x230
[  843.853068]        ksys_write+0x58/0xd0
[  843.853075]        do_syscall_64+0x33/0x40
[  843.853079]        entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  843.853081]
               other info that might help us debug this:

[  843.853083]  Possible unsafe locking scenario:

[  843.853087]        CPU0                    CPU1
[  843.853090]        ----                    ----
[  843.853091]   lock(&port->mutex);
[  843.853095]                                lock((work_completion)(&data->clk_work));
[  843.853098]                                lock(&port->mutex);
[  843.853101]   lock((work_completion)(&data->clk_work));
[  843.853105]
                *** DEADLOCK ***

[  843.853109] 7 locks held by systemd-sleep/1628:
[  843.853111]  #0: ffff935e302a9488 (sb_writers#4){.+.+}-{0:0}, at: vfs_write+0x1a0/0x230
[  843.853123]  #1: ffff935e0e56a290 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write+0xa5/0x1c0
[  843.853134]  #2: ffff935e392a7848 (kn->active#206){.+.+}-{0:0}, at: kernfs_fop_write+0xad/0x1c0
[  843.853144]  #3: ffffffffb487b0b0 (system_transition_mutex){+.+.}-{3:3}, at: pm_suspend.cold+0xee/0x389
[  843.853155]  #4: ffffffffb4a42370 (acpi_scan_lock){+.+.}-{3:3}, at: acpi_s2idle_begin+0xa/0x10
[  843.853167]  #5: ffff935e39ee29a0 (&dev->mutex){....}-{3:3}, at: __device_suspend+0xe8/0x450
[  843.853178]  #6: ffff935e302f1420 (&port->mutex){+.+.}-{3:3}, at: uart_suspend_port+0x3f/0x1f0
[  843.853187]
               stack backtrace:
[  843.853195] CPU: 3 PID: 1628 Comm: systemd-sleep Tainted: G        W   E     5.9.0-rc3+ linux-sunxi#38
[  843.853199] Hardware name: Acer One S1003/One S1003, BIOS V1.19 03/20/2018
[  843.853203] Call Trace:
[  843.853213]  dump_stack+0x8b/0xb8
[  843.853222]  check_noncircular+0x134/0x150
[  843.853234]  __lock_acquire+0x1238/0x2080
[  843.853244]  ? lock_acquire+0xa7/0x3d0
[  843.853252]  lock_acquire+0xa7/0x3d0
[  843.853257]  ? __flush_work+0x2e6/0x460
[  843.853265]  ? lockdep_hardirqs_on_prepare+0x116/0x190
[  843.853270]  ? asm_sysvec_apic_timer_interrupt+0x12/0x20
[  843.853276]  ? trace_hardirqs_on+0x1c/0xe0
[  843.853284]  __flush_work+0x30d/0x460
[  843.853289]  ? __flush_work+0x2e6/0x460
[  843.853295]  ? sched_clock+0x5/0x10
[  843.853300]  ? sched_clock_cpu+0xc/0xb0
[  843.853311]  ? __mutex_unlock_slowpath+0x35/0x270
[  843.853321]  ? clk_notifier_unregister+0xf8/0x120
[  843.853328]  uart_suspend_port+0x1b9/0x1f0
[  843.853337]  ? acpi_pm_notify_work_func+0x30/0x30
[  843.853342]  dw8250_suspend+0x10/0x20
[  843.853346]  dpm_run_callback+0x51/0xc0
[  843.853353]  __device_suspend+0x1f9/0x450
[  843.853360]  dpm_suspend+0x13d/0x1e0
[  843.853367]  dpm_suspend_start+0x77/0x80
[  843.853373]  suspend_devices_and_enter+0xe6/0x620
[  843.853381]  ? rcu_read_lock_sched_held+0x3f/0x80
[  843.853388]  pm_suspend.cold+0x333/0x389
[  843.853394]  state_store+0x71/0xd0
[  843.853405]  kernfs_fop_write+0xdc/0x1c0
[  843.853413]  vfs_write+0xec/0x230
[  843.853420]  ksys_write+0x58/0xd0
[  843.853427]  do_syscall_64+0x33/0x40
[  843.853432]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  843.853441] RIP: 0033:0x7f2a99d184b7
[  843.853450] Code: 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
[  843.853453] RSP: 002b:00007ffedaca0ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  843.853459] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f2a99d184b7
[  843.853462] RDX: 0000000000000004 RSI: 00007ffedaca0fe0 RDI: 0000000000000004
[  843.853465] RBP: 00007ffedaca0fe0 R08: 000000000000c0d0 R09: 00007f2a99daf0c0
[  843.853468] R10: 00007f2a99daefc0 R11: 0000000000000246 R12: 0000000000000004
[  843.853471] R13: 000055f1a8c67330 R14: 0000000000000004 R15: 00007f2a99dec720

So lets revert this for now.

This reverts commit cc81696.
jwrdegoede pushed a commit to jwrdegoede/linux-sunxi that referenced this issue Nov 18, 2020
…tect_depth

This oops manifests itself on the following hardware:
01:00.0 VGA compatible controller: NVIDIA Corporation G98M [GeForce G 103M] (rev a1)

Oct 09 14:17:46 lp-sasha kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: #PF: supervisor read access in kernel mode
Oct 09 14:17:46 lp-sasha kernel: #PF: error_code(0x0000) - not-present page
Oct 09 14:17:46 lp-sasha kernel: PGD 0 P4D 0
Oct 09 14:17:46 lp-sasha kernel: Oops: 0000 [#1] SMP PTI
Oct 09 14:17:46 lp-sasha kernel: CPU: 1 PID: 191 Comm: systemd-udevd Not tainted 5.9.0-rc8-next-20201009 linux-sunxi#38
Oct 09 14:17:46 lp-sasha kernel: Hardware name: Hewlett-Packard Compaq Presario CQ61 Notebook PC/306A, BIOS F.03 03/23/2009
Oct 09 14:17:46 lp-sasha kernel: RIP: 0010:nouveau_connector_detect_depth+0x71/0xc0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel: Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
Oct 09 14:17:46 lp-sasha kernel: RSP: 0018:ffffc9000028f8c0 EFLAGS: 00010297
Oct 09 14:17:46 lp-sasha kernel: RAX: 0000000000014c08 RBX: ffff8880369d4000 RCX: ffff8880369d3000
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffff8880369d4000
Oct 09 14:17:46 lp-sasha kernel: RBP: ffff88800601cc00 R08: ffff8880051da298 R09: ffffffff8226201a
Oct 09 14:17:46 lp-sasha kernel: R10: ffff88800469aa80 R11: ffff888004c84ff8 R12: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: R13: ffff8880051da000 R14: 0000000000002000 R15: 0000000000000003
Oct 09 14:17:46 lp-sasha kernel: FS:  00007fd0192b3440(0000) GS:ffff8880bc900000(0000) knlGS:0000000000000000
Oct 09 14:17:46 lp-sasha kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000 CR3: 0000000004976000 CR4: 00000000000006e0
Oct 09 14:17:46 lp-sasha kernel: Call Trace:
Oct 09 14:17:46 lp-sasha kernel:  nouveau_connector_get_modes+0x1e6/0x240 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? kfree+0xb9/0x240
Oct 09 14:17:46 lp-sasha kernel:  ? drm_connector_list_iter_next+0x7c/0xa0
Oct 09 14:17:46 lp-sasha kernel:  drm_helper_probe_single_connector_modes+0x1ba/0x7c0
Oct 09 14:17:46 lp-sasha kernel:  drm_client_modeset_probe+0x27e/0x1360
Oct 09 14:17:46 lp-sasha kernel:  ? nvif_object_sclass_put+0xc/0x20 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? nouveau_cli_init+0x3cc/0x440 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  ? ktime_get_mono_fast_ns+0x49/0xa0
Oct 09 14:17:46 lp-sasha kernel:  ? nouveau_drm_open+0x4e/0x180 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  __drm_fb_helper_initial_config_and_unlock+0x3f/0x4a0
Oct 09 14:17:46 lp-sasha kernel:  ? drm_file_alloc+0x18f/0x260
Oct 09 14:17:46 lp-sasha kernel:  ? mutex_lock+0x9/0x40
Oct 09 14:17:46 lp-sasha kernel:  ? drm_client_init+0x110/0x160
Oct 09 14:17:46 lp-sasha kernel:  nouveau_fbcon_init+0x14d/0x1c0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  nouveau_drm_device_init+0x1c0/0x880 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  nouveau_drm_probe+0x11a/0x1e0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel:  pci_device_probe+0xcd/0x140
Oct 09 14:17:46 lp-sasha kernel:  really_probe+0xd8/0x400
Oct 09 14:17:46 lp-sasha kernel:  driver_probe_device+0x4a/0xa0
Oct 09 14:17:46 lp-sasha kernel:  device_driver_attach+0x9c/0xc0
Oct 09 14:17:46 lp-sasha kernel:  __driver_attach+0x6f/0x100
Oct 09 14:17:46 lp-sasha kernel:  ? device_driver_attach+0xc0/0xc0
Oct 09 14:17:46 lp-sasha kernel:  bus_for_each_dev+0x75/0xc0
Oct 09 14:17:46 lp-sasha kernel:  bus_add_driver+0x106/0x1c0
Oct 09 14:17:46 lp-sasha kernel:  driver_register+0x86/0xe0
Oct 09 14:17:46 lp-sasha kernel:  ? 0xffffffffa044e000
Oct 09 14:17:46 lp-sasha kernel:  do_one_initcall+0x48/0x1e0
Oct 09 14:17:46 lp-sasha kernel:  ? _cond_resched+0x11/0x60
Oct 09 14:17:46 lp-sasha kernel:  ? kmem_cache_alloc_trace+0x19c/0x1e0
Oct 09 14:17:46 lp-sasha kernel:  do_init_module+0x57/0x220
Oct 09 14:17:46 lp-sasha kernel:  __do_sys_finit_module+0xa0/0xe0
Oct 09 14:17:46 lp-sasha kernel:  do_syscall_64+0x33/0x40
Oct 09 14:17:46 lp-sasha kernel:  entry_SYSCALL_64_after_hwframe+0x44/0xa9
Oct 09 14:17:46 lp-sasha kernel: RIP: 0033:0x7fd01a060d5d
Oct 09 14:17:46 lp-sasha kernel: Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e3 70 0c 00 f7 d8 64 89 01 48
Oct 09 14:17:46 lp-sasha kernel: RSP: 002b:00007ffc8ad38a98 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
Oct 09 14:17:46 lp-sasha kernel: RAX: ffffffffffffffda RBX: 0000563f6e7fd530 RCX: 00007fd01a060d5d
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000000 RSI: 00007fd01a19f95d RDI: 000000000000000f
Oct 09 14:17:46 lp-sasha kernel: RBP: 0000000000020000 R08: 0000000000000000 R09: 0000000000000007
Oct 09 14:17:46 lp-sasha kernel: R10: 000000000000000f R11: 0000000000000246 R12: 00007fd01a19f95d
Oct 09 14:17:46 lp-sasha kernel: R13: 0000000000000000 R14: 0000563f6e7fbc10 R15: 0000563f6e7fd530
Oct 09 14:17:46 lp-sasha kernel: Modules linked in: nouveau(+) ttm xt_string xt_mark xt_LOG vgem v4l2_dv_timings uvcvideo ulpi udf ts_kmp ts_fsm ts_bm snd_aloop sil164 qat_dh895xccvf nf_nat_sip nf_nat_irc nf_nat_ftp nf_nat nf_log_ipv6 nf_log_ipv4 nf_log_common ltc2990 lcd intel_qat input_leds i2c_mux gspca_main videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 videobuf2_common videodev mc drivetemp cuse fuse crc_itu_t coretemp ch7006 ath5k ath algif_hash
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: ---[ end trace 0ddafe218ad30017 ]---
Oct 09 14:17:46 lp-sasha kernel: RIP: 0010:nouveau_connector_detect_depth+0x71/0xc0 [nouveau]
Oct 09 14:17:46 lp-sasha kernel: Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
Oct 09 14:17:46 lp-sasha kernel: RSP: 0018:ffffc9000028f8c0 EFLAGS: 00010297
Oct 09 14:17:46 lp-sasha kernel: RAX: 0000000000014c08 RBX: ffff8880369d4000 RCX: ffff8880369d3000
Oct 09 14:17:46 lp-sasha kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffff8880369d4000
Oct 09 14:17:46 lp-sasha kernel: RBP: ffff88800601cc00 R08: ffff8880051da298 R09: ffffffff8226201a
Oct 09 14:17:46 lp-sasha kernel: R10: ffff88800469aa80 R11: ffff888004c84ff8 R12: 0000000000000000
Oct 09 14:17:46 lp-sasha kernel: R13: ffff8880051da000 R14: 0000000000002000 R15: 0000000000000003
Oct 09 14:17:46 lp-sasha kernel: FS:  00007fd0192b3440(0000) GS:ffff8880bc900000(0000) knlGS:0000000000000000
Oct 09 14:17:46 lp-sasha kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 09 14:17:46 lp-sasha kernel: CR2: 0000000000000000 CR3: 0000000004976000 CR4: 00000000000006e0

The disassembly:
Code: 0a 00 00 48 8b 49 48 c7 87 b8 00 00 00 06 00 00 00 80 b9 4d 0a 00 00 00 75 1e 83 fa 41 75 05 48 85 c0 75 29 8b 81 10 0d 00 00 <39> 06 7c 25 f6 81 14 0d 00 00 02 75 b7 c3 80 b9 0c 0d 00 00 00 75
All code
========
   0:   0a 00                   or     (%rax),%al
   2:   00 48 8b                add    %cl,-0x75(%rax)
   5:   49                      rex.WB
   6:   48 c7 87 b8 00 00 00    movq   $0x6,0xb8(%rdi)
   d:   06 00 00 00
  11:   80 b9 4d 0a 00 00 00    cmpb   $0x0,0xa4d(%rcx)
  18:   75 1e                   jne    0x38
  1a:   83 fa 41                cmp    $0x41,%edx
  1d:   75 05                   jne    0x24
  1f:   48 85 c0                test   %rax,%rax
  22:   75 29                   jne    0x4d
  24:   8b 81 10 0d 00 00       mov    0xd10(%rcx),%eax
  2a:*  39 06                   cmp    %eax,(%rsi)              <-- trapping instruction
  2c:   7c 25                   jl     0x53
  2e:   f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
  35:   75 b7                   jne    0xffffffffffffffee
  37:   c3                      retq
  38:   80 b9 0c 0d 00 00 00    cmpb   $0x0,0xd0c(%rcx)
  3f:   75                      .byte 0x75

Code starting with the faulting instruction
===========================================
   0:   39 06                   cmp    %eax,(%rsi)
   2:   7c 25                   jl     0x29
   4:   f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
   b:   75 b7                   jne    0xffffffffffffffc4
   d:   c3                      retq
   e:   80 b9 0c 0d 00 00 00    cmpb   $0x0,0xd0c(%rcx)
  15:   75                      .byte 0x75

objdump -SF --disassemble=nouveau_connector_detect_depth
[...]
        if (nv_connector->edid &&
   c85e1:       83 fa 41                cmp    $0x41,%edx
   c85e4:       75 05                   jne    c85eb <nouveau_connector_detect_depth+0x6b> (File Offset: 0xc866b)
   c85e6:       48 85 c0                test   %rax,%rax
   c85e9:       75 29                   jne    c8614 <nouveau_connector_detect_depth+0x94> (File Offset: 0xc8694)
            nv_connector->type == DCB_CONNECTOR_LVDS_SPWG)
                duallink = ((u8 *)nv_connector->edid)[121] == 2;
        else
                duallink = mode->clock >= bios->fp.duallink_transition_clk;

        if ((!duallink && (bios->fp.strapless_is_24bit & 1)) ||
   c85eb:       8b 81 10 0d 00 00       mov    0xd10(%rcx),%eax
   c85f1:       39 06                   cmp    %eax,(%rsi)
   c85f3:       7c 25                   jl     c861a <nouveau_connector_detect_depth+0x9a> (File Offset: 0xc869a)
            ( duallink && (bios->fp.strapless_is_24bit & 2)))
   c85f5:       f6 81 14 0d 00 00 02    testb  $0x2,0xd14(%rcx)
   c85fc:       75 b7                   jne    c85b5 <nouveau_connector_detect_depth+0x35> (File Offset: 0xc8635)
                connector->display_info.bpc = 8;
[...]

% scripts/faddr2line /lib/modules/5.9.0-rc8-next-20201009/kernel/drivers/gpu/drm/nouveau/nouveau.ko nouveau_connector_detect_depth+0x71/0xc0
nouveau_connector_detect_depth+0x71/0xc0:
nouveau_connector_detect_depth at /home/sasha/linux-next/drivers/gpu/drm/nouveau/nouveau_connector.c:891

It is actually line 889. See the disassembly below.
889                     duallink = mode->clock >= bios->fp.duallink_transition_clk;

The NULL pointer being dereferenced is mode.

Git bisect has identified the following commit as bad:
f28e32d drm/nouveau/kms: Don't change EDID when it hasn't actually changed

Here is the chain of events that causes the oops.
On entry to nouveau_connector_detect_lvds, edid is set to NULL.  The call
to nouveau_connector_detect sets nv_connector->edid to valid memory,
with status set to connector_status_connected and the flow of execution
branching to the out label.

The subsequent call to nouveau_connector_set_edid erronously clears
nv_connector->edid, via the local edid pointer which remains set to NULL.

Fix this by setting edid to the value of the just acquired
nv_connector->edid and executing the body of nouveau_connector_set_edid
only if nv_connector->edid and edid point to different memory addresses
thus preventing nv_connector->edid from being turned into a dangling
pointer.

Fixes: f28e32d ("drm/nouveau/kms: Don't change EDID when it hasn't actually changed")
Signed-off-by: Alexander Kapshuk <alexander.kapshuk@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
repojohnray pushed a commit to repojohnray/linux-sunxi-4.7.y that referenced this issue Mar 30, 2021
[ Upstream commit 623f279 ]

If GPU components have failed to bind, shutdown callback would fail with
the following backtrace. Add safeguard check to stop that oops from
happening and allow the board to reboot.

[   66.617046] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[   66.626066] Mem abort info:
[   66.628939]   ESR = 0x96000006
[   66.632088]   EC = 0x25: DABT (current EL), IL = 32 bits
[   66.637542]   SET = 0, FnV = 0
[   66.640688]   EA = 0, S1PTW = 0
[   66.643924] Data abort info:
[   66.646889]   ISV = 0, ISS = 0x00000006
[   66.650832]   CM = 0, WnR = 0
[   66.653890] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107f81000
[   66.660505] [0000000000000000] pgd=0000000100bb2003, p4d=0000000100bb2003, pud=0000000100897003, pmd=0000000000000000
[   66.671398] Internal error: Oops: 96000006 [jwrdegoede#1] PREEMPT SMP
[   66.677115] Modules linked in:
[   66.680261] CPU: 6 PID: 352 Comm: reboot Not tainted 5.11.0-rc2-00309-g79e3faa756b2 linux-sunxi#38
[   66.688473] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
[   66.695347] pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
[   66.701507] pc : msm_atomic_commit_tail+0x78/0x4e0
[   66.706437] lr : commit_tail+0xa4/0x184
[   66.710381] sp : ffff8000108f3af0
[   66.713791] x29: ffff8000108f3af0 x28: ffff418c44337000
[   66.719242] x27: 0000000000000000 x26: ffff418c40a24490
[   66.724693] x25: ffffd3a842a4f1a0 x24: 0000000000000008
[   66.730146] x23: ffffd3a84313f030 x22: ffff418c444ce000
[   66.735598] x21: ffff418c408a4980 x20: 0000000000000000
[   66.741049] x19: 0000000000000000 x18: ffff800010710fbc
[   66.746500] x17: 000000000000000c x16: 0000000000000001
[   66.751954] x15: 0000000000010008 x14: 0000000000000068
[   66.757405] x13: 0000000000000001 x12: 0000000000000000
[   66.762855] x11: 0000000000000001 x10: 00000000000009b0
[   66.768306] x9 : ffffd3a843192000 x8 : ffff418c44337000
[   66.773757] x7 : 0000000000000000 x6 : 00000000a401b34e
[   66.779210] x5 : 00ffffffffffffff x4 : 0000000000000000
[   66.784660] x3 : 0000000000000000 x2 : ffff418c444ce000
[   66.790111] x1 : ffffd3a841dce530 x0 : ffff418c444cf000
[   66.795563] Call trace:
[   66.798075]  msm_atomic_commit_tail+0x78/0x4e0
[   66.802633]  commit_tail+0xa4/0x184
[   66.806217]  drm_atomic_helper_commit+0x160/0x390
[   66.811051]  drm_atomic_commit+0x4c/0x60
[   66.815082]  drm_atomic_helper_disable_all+0x1f4/0x210
[   66.820355]  drm_atomic_helper_shutdown+0x80/0x130
[   66.825276]  msm_pdev_shutdown+0x14/0x20
[   66.829303]  platform_shutdown+0x28/0x40
[   66.833330]  device_shutdown+0x158/0x330
[   66.837357]  kernel_restart+0x40/0xa0
[   66.841122]  __do_sys_reboot+0x228/0x250
[   66.845148]  __arm64_sys_reboot+0x28/0x34
[   66.849264]  el0_svc_common.constprop.0+0x74/0x190
[   66.854187]  do_el0_svc+0x24/0x90
[   66.857595]  el0_svc+0x14/0x20
[   66.860739]  el0_sync_handler+0x1a4/0x1b0
[   66.864858]  el0_sync+0x174/0x180
[   66.868269] Code: 1ac020a0 2a000273 eb02007f 54ffff01 (f9400285)
[   66.874525] ---[ end trace 20dedb2a3229fec8 ]---

Fixes: 9d5cbf5 ("drm/msm: add shutdown support for display platform_driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
jwrdegoede pushed a commit to jwrdegoede/linux-sunxi that referenced this issue Apr 5, 2021
If GPU components have failed to bind, shutdown callback would fail with
the following backtrace. Add safeguard check to stop that oops from
happening and allow the board to reboot.

[   66.617046] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[   66.626066] Mem abort info:
[   66.628939]   ESR = 0x96000006
[   66.632088]   EC = 0x25: DABT (current EL), IL = 32 bits
[   66.637542]   SET = 0, FnV = 0
[   66.640688]   EA = 0, S1PTW = 0
[   66.643924] Data abort info:
[   66.646889]   ISV = 0, ISS = 0x00000006
[   66.650832]   CM = 0, WnR = 0
[   66.653890] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107f81000
[   66.660505] [0000000000000000] pgd=0000000100bb2003, p4d=0000000100bb2003, pud=0000000100897003, pmd=0000000000000000
[   66.671398] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[   66.677115] Modules linked in:
[   66.680261] CPU: 6 PID: 352 Comm: reboot Not tainted 5.11.0-rc2-00309-g79e3faa756b2 linux-sunxi#38
[   66.688473] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
[   66.695347] pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
[   66.701507] pc : msm_atomic_commit_tail+0x78/0x4e0
[   66.706437] lr : commit_tail+0xa4/0x184
[   66.710381] sp : ffff8000108f3af0
[   66.713791] x29: ffff8000108f3af0 x28: ffff418c44337000
[   66.719242] x27: 0000000000000000 x26: ffff418c40a24490
[   66.724693] x25: ffffd3a842a4f1a0 x24: 0000000000000008
[   66.730146] x23: ffffd3a84313f030 x22: ffff418c444ce000
[   66.735598] x21: ffff418c408a4980 x20: 0000000000000000
[   66.741049] x19: 0000000000000000 x18: ffff800010710fbc
[   66.746500] x17: 000000000000000c x16: 0000000000000001
[   66.751954] x15: 0000000000010008 x14: 0000000000000068
[   66.757405] x13: 0000000000000001 x12: 0000000000000000
[   66.762855] x11: 0000000000000001 x10: 00000000000009b0
[   66.768306] x9 : ffffd3a843192000 x8 : ffff418c44337000
[   66.773757] x7 : 0000000000000000 x6 : 00000000a401b34e
[   66.779210] x5 : 00ffffffffffffff x4 : 0000000000000000
[   66.784660] x3 : 0000000000000000 x2 : ffff418c444ce000
[   66.790111] x1 : ffffd3a841dce530 x0 : ffff418c444cf000
[   66.795563] Call trace:
[   66.798075]  msm_atomic_commit_tail+0x78/0x4e0
[   66.802633]  commit_tail+0xa4/0x184
[   66.806217]  drm_atomic_helper_commit+0x160/0x390
[   66.811051]  drm_atomic_commit+0x4c/0x60
[   66.815082]  drm_atomic_helper_disable_all+0x1f4/0x210
[   66.820355]  drm_atomic_helper_shutdown+0x80/0x130
[   66.825276]  msm_pdev_shutdown+0x14/0x20
[   66.829303]  platform_shutdown+0x28/0x40
[   66.833330]  device_shutdown+0x158/0x330
[   66.837357]  kernel_restart+0x40/0xa0
[   66.841122]  __do_sys_reboot+0x228/0x250
[   66.845148]  __arm64_sys_reboot+0x28/0x34
[   66.849264]  el0_svc_common.constprop.0+0x74/0x190
[   66.854187]  do_el0_svc+0x24/0x90
[   66.857595]  el0_svc+0x14/0x20
[   66.860739]  el0_sync_handler+0x1a4/0x1b0
[   66.864858]  el0_sync+0x174/0x180
[   66.868269] Code: 1ac020a0 2a000273 eb02007f 54ffff01 (f9400285)
[   66.874525] ---[ end trace 20dedb2a3229fec8 ]---

Fixes: 9d5cbf5 ("drm/msm: add shutdown support for display platform_driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>
repojohnray pushed a commit to repojohnray/linux-sunxi-4.7.y that referenced this issue Apr 7, 2021
[ Upstream commit 623f279 ]

If GPU components have failed to bind, shutdown callback would fail with
the following backtrace. Add safeguard check to stop that oops from
happening and allow the board to reboot.

[   66.617046] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[   66.626066] Mem abort info:
[   66.628939]   ESR = 0x96000006
[   66.632088]   EC = 0x25: DABT (current EL), IL = 32 bits
[   66.637542]   SET = 0, FnV = 0
[   66.640688]   EA = 0, S1PTW = 0
[   66.643924] Data abort info:
[   66.646889]   ISV = 0, ISS = 0x00000006
[   66.650832]   CM = 0, WnR = 0
[   66.653890] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000107f81000
[   66.660505] [0000000000000000] pgd=0000000100bb2003, p4d=0000000100bb2003, pud=0000000100897003, pmd=0000000000000000
[   66.671398] Internal error: Oops: 96000006 [jwrdegoede#1] PREEMPT SMP
[   66.677115] Modules linked in:
[   66.680261] CPU: 6 PID: 352 Comm: reboot Not tainted 5.11.0-rc2-00309-g79e3faa756b2 linux-sunxi#38
[   66.688473] Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT)
[   66.695347] pstate: 60400005 (nZCv daif +PAN -UAO -TCO BTYPE=--)
[   66.701507] pc : msm_atomic_commit_tail+0x78/0x4e0
[   66.706437] lr : commit_tail+0xa4/0x184
[   66.710381] sp : ffff8000108f3af0
[   66.713791] x29: ffff8000108f3af0 x28: ffff418c44337000
[   66.719242] x27: 0000000000000000 x26: ffff418c40a24490
[   66.724693] x25: ffffd3a842a4f1a0 x24: 0000000000000008
[   66.730146] x23: ffffd3a84313f030 x22: ffff418c444ce000
[   66.735598] x21: ffff418c408a4980 x20: 0000000000000000
[   66.741049] x19: 0000000000000000 x18: ffff800010710fbc
[   66.746500] x17: 000000000000000c x16: 0000000000000001
[   66.751954] x15: 0000000000010008 x14: 0000000000000068
[   66.757405] x13: 0000000000000001 x12: 0000000000000000
[   66.762855] x11: 0000000000000001 x10: 00000000000009b0
[   66.768306] x9 : ffffd3a843192000 x8 : ffff418c44337000
[   66.773757] x7 : 0000000000000000 x6 : 00000000a401b34e
[   66.779210] x5 : 00ffffffffffffff x4 : 0000000000000000
[   66.784660] x3 : 0000000000000000 x2 : ffff418c444ce000
[   66.790111] x1 : ffffd3a841dce530 x0 : ffff418c444cf000
[   66.795563] Call trace:
[   66.798075]  msm_atomic_commit_tail+0x78/0x4e0
[   66.802633]  commit_tail+0xa4/0x184
[   66.806217]  drm_atomic_helper_commit+0x160/0x390
[   66.811051]  drm_atomic_commit+0x4c/0x60
[   66.815082]  drm_atomic_helper_disable_all+0x1f4/0x210
[   66.820355]  drm_atomic_helper_shutdown+0x80/0x130
[   66.825276]  msm_pdev_shutdown+0x14/0x20
[   66.829303]  platform_shutdown+0x28/0x40
[   66.833330]  device_shutdown+0x158/0x330
[   66.837357]  kernel_restart+0x40/0xa0
[   66.841122]  __do_sys_reboot+0x228/0x250
[   66.845148]  __arm64_sys_reboot+0x28/0x34
[   66.849264]  el0_svc_common.constprop.0+0x74/0x190
[   66.854187]  do_el0_svc+0x24/0x90
[   66.857595]  el0_svc+0x14/0x20
[   66.860739]  el0_sync_handler+0x1a4/0x1b0
[   66.864858]  el0_sync+0x174/0x180
[   66.868269] Code: 1ac020a0 2a000273 eb02007f 54ffff01 (f9400285)
[   66.874525] ---[ end trace 20dedb2a3229fec8 ]---

Fixes: 9d5cbf5 ("drm/msm: add shutdown support for display platform_driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
jwrdegoede pushed a commit to jwrdegoede/linux-sunxi that referenced this issue Apr 28, 2022
This patch fixes a memory corruption that occurred in the
nand_scan() path for Hynix nand device.

On boot, for Hynix nand device will panic at a weird place:
| Unable to handle kernel NULL pointer dereference at virtual
  address 00000070
| [00000070] *pgd=00000000
| Internal error: Oops: 5 [#1] PREEMPT SMP ARM
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
  linux-sunxi#38
| Hardware name: Generic DT based system
| PC is at nandc_set_reg+0x8/0x1c
| LR is at qcom_nandc_command+0x20c/0x5d0
| pc : [<c088b74c>]    lr : [<c088d9c8>]    psr: 00000113
| sp : c14adc50  ip : c14ee208  fp : c0cc970c
| r10: 000000a3  r9 : 00000000  r8 : 00000040
| r7 : c16f6a00  r6 : 00000090  r5 : 00000004  r4 :c14ee040
| r3 : 00000000  r2 : 0000000b  r1 : 00000000  r0 :c14ee040
| Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment none
| Control: 10c5387d  Table: 8020406a  DAC: 00000051
| Register r0 information: slab kmalloc-2k start c14ee000 pointer offset
  64 size 2048
| Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
| nandc_set_reg from qcom_nandc_command+0x20c/0x5d0
| qcom_nandc_command from nand_readid_op+0x198/0x1e8
| nand_readid_op from hynix_nand_has_valid_jedecid+0x30/0x78
| hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
| hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
| nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
| qcom_nandc_probe from platform_probe+0x58/0xac

The problem is that the nand_scan()'s qcom_nand_attach_chip callback
is updating the nandc->max_cwperpage from 1 to 4 or 8 based on page size.
This causes the sg_init_table of clear_bam_transaction() in the driver's
qcom_nandc_command() to memset much more than what was initially
allocated by alloc_bam_transaction().

This patch will update nandc->max_cwperpage 1 to 4 or 8 based on page
size in qcom_nand_attach_chip call back after freeing the previously
allocated memory for bam txn as per nandc->max_cwperpage = 1 and then
again allocating bam txn as per nandc->max_cwperpage = 4 or 8 based on
page size in qcom_nand_attach_chip call back itself.

Cc: stable@vger.kernel.org
Fixes: 6a3cec6 ("mtd: rawnand: qcom: convert driver to nand_scan()")
Reported-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Co-developed-by: Sricharan R <quic_srichara@quicinc.com>
Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/1650268107-5363-1-git-send-email-quic_mdalam@quicinc.com
repojohnray pushed a commit to repojohnray/linux-sunxi-4.7.y that referenced this issue May 10, 2022
commit ba7542e upstream.

This patch fixes a memory corruption that occurred in the
nand_scan() path for Hynix nand device.

On boot, for Hynix nand device will panic at a weird place:
| Unable to handle kernel NULL pointer dereference at virtual
  address 00000070
| [00000070] *pgd=00000000
| Internal error: Oops: 5 [jwrdegoede#1] PREEMPT SMP ARM
| Modules linked in:
| CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-01473-g13ae1769cfb0
  linux-sunxi#38
| Hardware name: Generic DT based system
| PC is at nandc_set_reg+0x8/0x1c
| LR is at qcom_nandc_command+0x20c/0x5d0
| pc : [<c088b74c>]    lr : [<c088d9c8>]    psr: 00000113
| sp : c14adc50  ip : c14ee208  fp : c0cc970c
| r10: 000000a3  r9 : 00000000  r8 : 00000040
| r7 : c16f6a00  r6 : 00000090  r5 : 00000004  r4 :c14ee040
| r3 : 00000000  r2 : 0000000b  r1 : 00000000  r0 :c14ee040
| Flags: nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM Segment none
| Control: 10c5387d  Table: 8020406a  DAC: 00000051
| Register r0 information: slab kmalloc-2k start c14ee000 pointer offset
  64 size 2048
| Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
| nandc_set_reg from qcom_nandc_command+0x20c/0x5d0
| qcom_nandc_command from nand_readid_op+0x198/0x1e8
| nand_readid_op from hynix_nand_has_valid_jedecid+0x30/0x78
| hynix_nand_has_valid_jedecid from hynix_nand_init+0xb8/0x454
| hynix_nand_init from nand_scan_with_ids+0xa30/0x14a8
| nand_scan_with_ids from qcom_nandc_probe+0x648/0x7b0
| qcom_nandc_probe from platform_probe+0x58/0xac

The problem is that the nand_scan()'s qcom_nand_attach_chip callback
is updating the nandc->max_cwperpage from 1 to 4 or 8 based on page size.
This causes the sg_init_table of clear_bam_transaction() in the driver's
qcom_nandc_command() to memset much more than what was initially
allocated by alloc_bam_transaction().

This patch will update nandc->max_cwperpage 1 to 4 or 8 based on page
size in qcom_nand_attach_chip call back after freeing the previously
allocated memory for bam txn as per nandc->max_cwperpage = 1 and then
again allocating bam txn as per nandc->max_cwperpage = 4 or 8 based on
page size in qcom_nand_attach_chip call back itself.

Cc: stable@vger.kernel.org
Fixes: 6a3cec6 ("mtd: rawnand: qcom: convert driver to nand_scan()")
Reported-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Co-developed-by: Sricharan R <quic_srichara@quicinc.com>
Signed-off-by: Sricharan R <quic_srichara@quicinc.com>
Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/1650268107-5363-1-git-send-email-quic_mdalam@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jwrdegoede pushed a commit to jwrdegoede/linux-sunxi that referenced this issue Feb 24, 2023
If a non-root cgroup gets removed when there is a thread that registered
trigger and is polling on a pressure file within the cgroup, the polling
waitqueue gets freed in the following path:

 do_rmdir
   cgroup_rmdir
     kernfs_drain_open_files
       cgroup_file_release
         cgroup_pressure_release
           psi_trigger_destroy

However, the polling thread still has a reference to the pressure file and
will access the freed waitqueue when the file is closed or upon exit:

 fput
   ep_eventpoll_release
     ep_free
       ep_remove_wait_queue
         remove_wait_queue

This results in use-after-free as pasted below.

The fundamental problem here is that cgroup_file_release() (and
consequently waitqueue's lifetime) is not tied to the file's real lifetime.
Using wake_up_pollfree() here might be less than ideal, but it is in line
with the comment at commit 42288cb ("wait: add wake_up_pollfree()")
since the waitqueue's lifetime is not tied to file's one and can be
considered as another special case. While this would be fixable by somehow
making cgroup_file_release() be tied to the fput(), it would require
sizable refactoring at cgroups or higher layer which might be more
justifiable if we identify more cases like this.

  BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x60/0xc0
  Write of size 4 at addr ffff88810e625328 by task a.out/4404

	CPU: 19 PID: 4404 Comm: a.out Not tainted 6.2.0-rc6 linux-sunxi#38
	Hardware name: Amazon EC2 c5a.8xlarge/, BIOS 1.0 10/16/2017
	Call Trace:
	<TASK>
	dump_stack_lvl+0x73/0xa0
	print_report+0x16c/0x4e0
	kasan_report+0xc3/0xf0
	kasan_check_range+0x2d2/0x310
	_raw_spin_lock_irqsave+0x60/0xc0
	remove_wait_queue+0x1a/0xa0
	ep_free+0x12c/0x170
	ep_eventpoll_release+0x26/0x30
	__fput+0x202/0x400
	task_work_run+0x11d/0x170
	do_exit+0x495/0x1130
	do_group_exit+0x100/0x100
	get_signal+0xd67/0xde0
	arch_do_signal_or_restart+0x2a/0x2b0
	exit_to_user_mode_prepare+0x94/0x100
	syscall_exit_to_user_mode+0x20/0x40
	do_syscall_64+0x52/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd
	</TASK>

 Allocated by task 4404:

	kasan_set_track+0x3d/0x60
	__kasan_kmalloc+0x85/0x90
	psi_trigger_create+0x113/0x3e0
	pressure_write+0x146/0x2e0
	cgroup_file_write+0x11c/0x250
	kernfs_fop_write_iter+0x186/0x220
	vfs_write+0x3d8/0x5c0
	ksys_write+0x90/0x110
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

 Freed by task 4407:

	kasan_set_track+0x3d/0x60
	kasan_save_free_info+0x27/0x40
	____kasan_slab_free+0x11d/0x170
	slab_free_freelist_hook+0x87/0x150
	__kmem_cache_free+0xcb/0x180
	psi_trigger_destroy+0x2e8/0x310
	cgroup_file_release+0x4f/0xb0
	kernfs_drain_open_files+0x165/0x1f0
	kernfs_drain+0x162/0x1a0
	__kernfs_remove+0x1fb/0x310
	kernfs_remove_by_name_ns+0x95/0xe0
	cgroup_addrm_files+0x67f/0x700
	cgroup_destroy_locked+0x283/0x3c0
	cgroup_rmdir+0x29/0x100
	kernfs_iop_rmdir+0xd1/0x140
	vfs_rmdir+0xfe/0x240
	do_rmdir+0x13d/0x280
	__x64_sys_rmdir+0x2c/0x30
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 0e94682 ("psi: introduce psi monitor")
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Mengchi Cheng <mengcc@amazon.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/20230106224859.4123476-1-kamatam@amazon.com/
Link: https://lore.kernel.org/r/20230214212705.4058045-1-kamatam@amazon.com
repojohnray pushed a commit to repojohnray/linux-sunxi-4.7.y that referenced this issue Mar 23, 2023
commit c2dbe32 upstream.

If a non-root cgroup gets removed when there is a thread that registered
trigger and is polling on a pressure file within the cgroup, the polling
waitqueue gets freed in the following path:

 do_rmdir
   cgroup_rmdir
     kernfs_drain_open_files
       cgroup_file_release
         cgroup_pressure_release
           psi_trigger_destroy

However, the polling thread still has a reference to the pressure file and
will access the freed waitqueue when the file is closed or upon exit:

 fput
   ep_eventpoll_release
     ep_free
       ep_remove_wait_queue
         remove_wait_queue

This results in use-after-free as pasted below.

The fundamental problem here is that cgroup_file_release() (and
consequently waitqueue's lifetime) is not tied to the file's real lifetime.
Using wake_up_pollfree() here might be less than ideal, but it is in line
with the comment at commit 42288cb ("wait: add wake_up_pollfree()")
since the waitqueue's lifetime is not tied to file's one and can be
considered as another special case. While this would be fixable by somehow
making cgroup_file_release() be tied to the fput(), it would require
sizable refactoring at cgroups or higher layer which might be more
justifiable if we identify more cases like this.

  BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x60/0xc0
  Write of size 4 at addr ffff88810e625328 by task a.out/4404

	CPU: 19 PID: 4404 Comm: a.out Not tainted 6.2.0-rc6 linux-sunxi#38
	Hardware name: Amazon EC2 c5a.8xlarge/, BIOS 1.0 10/16/2017
	Call Trace:
	<TASK>
	dump_stack_lvl+0x73/0xa0
	print_report+0x16c/0x4e0
	kasan_report+0xc3/0xf0
	kasan_check_range+0x2d2/0x310
	_raw_spin_lock_irqsave+0x60/0xc0
	remove_wait_queue+0x1a/0xa0
	ep_free+0x12c/0x170
	ep_eventpoll_release+0x26/0x30
	__fput+0x202/0x400
	task_work_run+0x11d/0x170
	do_exit+0x495/0x1130
	do_group_exit+0x100/0x100
	get_signal+0xd67/0xde0
	arch_do_signal_or_restart+0x2a/0x2b0
	exit_to_user_mode_prepare+0x94/0x100
	syscall_exit_to_user_mode+0x20/0x40
	do_syscall_64+0x52/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd
	</TASK>

 Allocated by task 4404:

	kasan_set_track+0x3d/0x60
	__kasan_kmalloc+0x85/0x90
	psi_trigger_create+0x113/0x3e0
	pressure_write+0x146/0x2e0
	cgroup_file_write+0x11c/0x250
	kernfs_fop_write_iter+0x186/0x220
	vfs_write+0x3d8/0x5c0
	ksys_write+0x90/0x110
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

 Freed by task 4407:

	kasan_set_track+0x3d/0x60
	kasan_save_free_info+0x27/0x40
	____kasan_slab_free+0x11d/0x170
	slab_free_freelist_hook+0x87/0x150
	__kmem_cache_free+0xcb/0x180
	psi_trigger_destroy+0x2e8/0x310
	cgroup_file_release+0x4f/0xb0
	kernfs_drain_open_files+0x165/0x1f0
	kernfs_drain+0x162/0x1a0
	__kernfs_remove+0x1fb/0x310
	kernfs_remove_by_name_ns+0x95/0xe0
	cgroup_addrm_files+0x67f/0x700
	cgroup_destroy_locked+0x283/0x3c0
	cgroup_rmdir+0x29/0x100
	kernfs_iop_rmdir+0xd1/0x140
	vfs_rmdir+0xfe/0x240
	do_rmdir+0x13d/0x280
	__x64_sys_rmdir+0x2c/0x30
	do_syscall_64+0x43/0x90
	entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 0e94682 ("psi: introduce psi monitor")
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Mengchi Cheng <mengcc@amazon.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/20230106224859.4123476-1-kamatam@amazon.com/
Link: https://lore.kernel.org/r/20230214212705.4058045-1-kamatam@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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