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Bugfix/fmradio #1

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Bugfix/fmradio #1

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115ek
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@115ek 115ek commented Sep 18, 2021

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Venkateshwarlu Domakonda and others added 10 commits September 18, 2021 22:02
Provide interfaces to allow host to update the spur table.
To remove platform dependent spurs, host has to update
the spur table in SOC.

CRs-Fixed: 664779
Change-Id: I37697fa35c19398a4bceb2bf73fb28554417e6d7
Signed-off-by: Venkateshwarlu Domakonda <vdomak@codeaurora.org>
Configure the signal blending parameters BlendSinrHi & BlendRmssiHi.

CRs-Fixed: 753525
Signed-off-by: Venkateshwarlu Domakonda <vdomak@codeaurora.org>
Change-Id: Icd38b3f8ada232252660773dfb4f0d69ffad3634
Fix schedule_timeout() argument as it takes jiffies instead
of milliseconds as argument.

Change-Id: Ie5be2551d4cb889f51399af72495627a3b0c62ec
Signed-off-by: Dibyendu Roy <dibyen@codeaurora.org>
After fm is killed abnormally,
1) we must make sure wakeup event can be received before
   10s timeout.
2) disable event should not be sent to userspace of fm.

CRs-Fixed: 967734
Change-Id: I96c1f577fce2bd5fcdd0e5b2b6bc2000d61a0bce
Signed-off-by: Mingbo Zhang <mingboz@codeaurora.org>
On FM closure, free the memory allocated for hci device. Make the
register/unregister call symmetric. Also, do not free the video device on
FM closure as it is allocated in platform driver probe and removed in
remove call.

CRs-Fixed: 981131
Change-Id: Ibc5d287083572ab1686a91cc7b934ae66f749e27
Signed-off-by: Rupesh Tatiya <rtatiya@codeaurora.org>
Fix multiple times fmsmd_set module parameter set/unset. Add condition to
check whether channel is already opened or closed. This fixes the
incorrect error state caused by consecutive fmsmd_set set or unset.

Change-Id: I8b67e8308d9e8c3c0779c360712c90605e2fbdea
Signed-off-by: Dibyendu Roy <dibyen@codeaurora.org>
Signed-off-by: Rupesh Tatiya <rtatiya@codeaurora.org>
iris_fops_release function can be called in parallel and this may result in
accessing freed memory in close_smd operation. Serialize the access to
close_smd and call it only if it is valid.

Change-Id: I9dd00625866c2f0da12ae0d35896f0683bd1453f
Signed-off-by: Rupesh Tatiya <rtatiya@codeaurora.org>
Add condition to check whether channel is already opened or closed.
This will prevent smd channel to reopen if it is already opened.

Change-Id: I82cbe05062d3ee58969586e70dc46dc829e529f3
Signed-off-by: Kamal Negi <kamaln@codeaurora.org>
Check arguments passed in an ioctl before copying the data to kernel
buffers. If user sends an erroneous data, data length more than expected,
will lead to buffer overflow.

Change-Id: I663e937806f38dc3b04c8d7662cd8b045facd12b
Signed-off-by: Kamal Negi <kamaln@codeaurora.org>
Directly accessing userspace memory pointer in kernel space without
checking validity of pointer. This can lead to security vulnerability.
Use copy_from_user API's to make sure there is no illegal memory access.

Change-Id: I66a0b1931814ee19634a30dee02a5600066aa70b
Signed-off-by: Kamal Negi <kamaln@codeaurora.org>
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115ek commented Sep 18, 2021

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115ek commented Sep 18, 2021

Without these patches I directly ran into a crashing fm:
09-18 20:54:34.931 0 0 E iris_radio: Err on disable FM -4
Could only be resolved by a reboot.
After reboot it worked fine. Seems to be a spontaneous problem.

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115ek commented Sep 19, 2021

Solved by #2

@115ek 115ek closed this Sep 19, 2021
MSe1969 pushed a commit that referenced this pull request Mar 12, 2022
As Wen Xu reported in bugzilla, after image was injected with random data
by fuzzing, inline inode would contain invalid reserved blkaddr, then
during inline conversion, we will encounter illegal memory accessing
reported by KASAN, the root cause of this is when writing out converted
inline page, we will use invalid reserved blkaddr to update sit bitmap,
result in accessing memory beyond sit bitmap boundary.

In order to fix this issue, let's do sanity check with reserved block
address of inline inode to avoid above condition.

https://bugzilla.kernel.org/show_bug.cgi?id=200179

[ 1428.846352] BUG: KASAN: use-after-free in update_sit_entry+0x80/0x7f0
[ 1428.846618] Read of size 4 at addr ffff880194483540 by task a.out/2741

[ 1428.846855] CPU: 0 PID: 2741 Comm: a.out Tainted: G        W         4.17.0+ #1
[ 1428.846858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[ 1428.846860] Call Trace:
[ 1428.846868]  dump_stack+0x71/0xab
[ 1428.846875]  print_address_description+0x6b/0x290
[ 1428.846881]  kasan_report+0x28e/0x390
[ 1428.846888]  ? update_sit_entry+0x80/0x7f0
[ 1428.846898]  update_sit_entry+0x80/0x7f0
[ 1428.846906]  f2fs_allocate_data_block+0x6db/0xc70
[ 1428.846914]  ? f2fs_get_node_info+0x14f/0x590
[ 1428.846920]  do_write_page+0xc8/0x150
[ 1428.846928]  f2fs_outplace_write_data+0xfe/0x210
[ 1428.846935]  ? f2fs_do_write_node_page+0x170/0x170
[ 1428.846941]  ? radix_tree_tag_clear+0xff/0x130
[ 1428.846946]  ? __mod_node_page_state+0x22/0xa0
[ 1428.846951]  ? inc_zone_page_state+0x54/0x100
[ 1428.846956]  ? __test_set_page_writeback+0x336/0x5d0
[ 1428.846964]  f2fs_convert_inline_page+0x407/0x6d0
[ 1428.846971]  ? f2fs_read_inline_data+0x3b0/0x3b0
[ 1428.846978]  ? __get_node_page+0x335/0x6b0
[ 1428.846987]  f2fs_convert_inline_inode+0x41b/0x500
[ 1428.846994]  ? f2fs_convert_inline_page+0x6d0/0x6d0
[ 1428.847000]  ? kasan_unpoison_shadow+0x31/0x40
[ 1428.847005]  ? kasan_kmalloc+0xa6/0xd0
[ 1428.847024]  f2fs_file_mmap+0x79/0xc0
[ 1428.847029]  mmap_region+0x58b/0x880
[ 1428.847037]  ? arch_get_unmapped_area+0x370/0x370
[ 1428.847042]  do_mmap+0x55b/0x7a0
[ 1428.847048]  vm_mmap_pgoff+0x16f/0x1c0
[ 1428.847055]  ? vma_is_stack_for_current+0x50/0x50
[ 1428.847062]  ? __fsnotify_update_child_dentry_flags.part.1+0x160/0x160
[ 1428.847068]  ? do_sys_open+0x206/0x2a0
[ 1428.847073]  ? __fget+0xb4/0x100
[ 1428.847079]  ksys_mmap_pgoff+0x278/0x360
[ 1428.847085]  ? find_mergeable_anon_vma+0x50/0x50
[ 1428.847091]  do_syscall_64+0x73/0x160
[ 1428.847098]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1428.847102] RIP: 0033:0x7fb1430766ba
[ 1428.847103] Code: 89 f5 41 54 49 89 fc 55 53 74 35 49 63 e8 48 63 da 4d 89 f9 49 89 e8 4d 63 d6 48 89 da 4c 89 ee 4c 89 e7 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 56 5b 5d 41 5c 41 5d 41 5e 41 5f c3 0f 1f 00
[ 1428.847162] RSP: 002b:00007ffc651d9388 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
[ 1428.847167] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fb1430766ba
[ 1428.847170] RDX: 0000000000000001 RSI: 0000000000001000 RDI: 0000000000000000
[ 1428.847173] RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000000
[ 1428.847176] R10: 0000000000008002 R11: 0000000000000246 R12: 0000000000000000
[ 1428.847179] R13: 0000000000001000 R14: 0000000000008002 R15: 0000000000000000

[ 1428.847252] Allocated by task 2683:
[ 1428.847372]  kasan_kmalloc+0xa6/0xd0
[ 1428.847380]  kmem_cache_alloc+0xc8/0x1e0
[ 1428.847385]  getname_flags+0x73/0x2b0
[ 1428.847390]  user_path_at_empty+0x1d/0x40
[ 1428.847395]  vfs_statx+0xc1/0x150
[ 1428.847401]  __do_sys_newlstat+0x7e/0xd0
[ 1428.847405]  do_syscall_64+0x73/0x160
[ 1428.847411]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[ 1428.847466] Freed by task 2683:
[ 1428.847566]  __kasan_slab_free+0x137/0x190
[ 1428.847571]  kmem_cache_free+0x85/0x1e0
[ 1428.847575]  filename_lookup+0x191/0x280
[ 1428.847580]  vfs_statx+0xc1/0x150
[ 1428.847585]  __do_sys_newlstat+0x7e/0xd0
[ 1428.847590]  do_syscall_64+0x73/0x160
[ 1428.847596]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[ 1428.847648] The buggy address belongs to the object at ffff880194483300
                which belongs to the cache names_cache of size 4096
[ 1428.847946] The buggy address is located 576 bytes inside of
                4096-byte region [ffff880194483300, ffff880194484300)
[ 1428.848234] The buggy address belongs to the page:
[ 1428.848366] page:ffffea0006512000 count:1 mapcount:0 mapping:ffff8801f3586380 index:0x0 compound_mapcount: 0
[ 1428.848606] flags: 0x17fff8000008100(slab|head)
[ 1428.848737] raw: 017fff8000008100 dead000000000100 dead000000000200 ffff8801f3586380
[ 1428.848931] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
[ 1428.849122] page dumped because: kasan: bad access detected

[ 1428.849305] Memory state around the buggy address:
[ 1428.849436]  ffff880194483400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1428.849620]  ffff880194483480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1428.849804] >ffff880194483500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1428.849985]                                            ^
[ 1428.850120]  ffff880194483580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1428.850303]  ffff880194483600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 1428.850498] ==================================================================

Reported-by: Wen Xu <wen.xu@gatech.edu>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
CVE-2018-13099
Signed-off-by: Kevin F. Haggerty <haggertk@lineageos.org>

Change-Id: I9eac102ecd7c338131eda28878142d7eec7e0543
MSe1969 pushed a commit that referenced this pull request Aug 25, 2022
If the netdev is accessed before the urbs are initialized,
there will be NULL pointer dereferences. That is avoided by
registering it when it is fully initialized.

This case occurs e.g. if dhcpcd is running in the background
and the device is probed, either after insmod hso or
when the device appears on the usb bus.

A backtrace is the following:

[ 1357.356048] usb 1-2: new high-speed USB device number 12 using ehci-omap
[ 1357.551177] usb 1-2: New USB device found, idVendor=0af0, idProduct=8800
[ 1357.558654] usb 1-2: New USB device strings: Mfr=3, Product=2, SerialNumber=0
[ 1357.568572] usb 1-2: Product: Globetrotter HSUPA Modem
[ 1357.574096] usb 1-2: Manufacturer: Option N.V.
[ 1357.685882] hso 1-2:1.5: Not our interface
[ 1460.886352] hso: unloaded
[ 1460.889984] usbcore: deregistering interface driver hso
[ 1513.769134] hso: ../drivers/net/usb/hso.c: Option Wireless
[ 1513.846771] Unable to handle kernel NULL pointer dereference at virtual address 00000030
[ 1513.887664] hso 1-2:1.5: Not our interface
[ 1513.906890] usbcore: registered new interface driver hso
[ 1513.937988] pgd = ecdec000
[ 1513.949890] [00000030] *pgd=acd15831, *pte=00000000, *ppte=00000000
[ 1513.956573] Internal error: Oops: 817 [#1] PREEMPT SMP ARM
[ 1513.962371] Modules linked in: hso usb_f_ecm omap2430 bnep bluetooth g_ether usb_f_rndis u_ether libcomposite configfs ipv6 arc4 wl18xx wlcore mac80211 cfg80211 bq27xxx_battery panel_tpo_td028ttec1 omapdrm drm_kms_helper cfbfillrect snd_soc_simple_card syscopyarea cfbimgblt snd_soc_simple_card_utils sysfillrect sysimgblt fb_sys_fops snd_soc_omap_twl4030 cfbcopyarea encoder_opa362 drm twl4030_madc_hwmon wwan_on_off snd_soc_gtm601 pwm_omap_dmtimer generic_adc_battery connector_analog_tv pwm_bl extcon_gpio omap3_isp wlcore_sdio videobuf2_dma_contig videobuf2_memops w1_bq27000 videobuf2_v4l2 videobuf2_core omap_hdq snd_soc_omap_mcbsp ov9650 snd_soc_omap bmp280_i2c bmg160_i2c v4l2_common snd_pcm_dmaengine bmp280 bmg160_core at24 bmc150_magn_i2c nvmem_core videodev phy_twl4030_usb bmc150_accel_i2c tsc2007
[ 1514.037384]  bmc150_magn bmc150_accel_core media leds_tca6507 bno055 industrialio_triggered_buffer kfifo_buf gpio_twl4030 musb_hdrc snd_soc_twl4030 twl4030_vibra twl4030_madc twl4030_pwrbutton twl4030_charger industrialio w2sg0004 ehci_omap omapdss [last unloaded: hso]
[ 1514.062622] CPU: 0 PID: 3433 Comm: dhcpcd Tainted: G        W       4.11.0-rc8-letux+ #1
[ 1514.071136] Hardware name: Generic OMAP36xx (Flattened Device Tree)
[ 1514.077758] task: ee748240 task.stack: ecdd6000
[ 1514.082580] PC is at hso_start_net_device+0x50/0xc0 [hso]
[ 1514.088287] LR is at hso_net_open+0x68/0x84 [hso]
[ 1514.093231] pc : [<bf79c304>]    lr : [<bf79ced8>]    psr: a00f0013
sp : ecdd7e20  ip : 00000000  fp : ffffffff
[ 1514.105316] r10: 00000000  r9 : ed0e080c  r8 : ecd8fe2c
[ 1514.110839] r7 : bf79cef4  r6 : ecd8fe00  r5 : 00000000  r4 : ed0dbd80
[ 1514.117706] r3 : 00000000  r2 : c0020c80  r1 : 00000000  r0 : ecdb7800
[ 1514.124572] Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[ 1514.132110] Control: 10c5387d  Table: acdec019  DAC: 00000051
[ 1514.138153] Process dhcpcd (pid: 3433, stack limit = 0xecdd6218)
[ 1514.144470] Stack: (0xecdd7e20 to 0xecdd8000)
[ 1514.149078] 7e20: ed0dbd80 ecd8fe98 00000001 00000000 ecd8f800 ecd8fe00 ecd8fe60 00000000
[ 1514.157714] 7e40: ed0e080c bf79ced8 bf79ce70 ecd8f800 00000001 bf7a0258 ecd8f830 c068d958
[ 1514.166320] 7e60: c068d8b8 ecd8f800 00000001 00001091 00001090 c068dba4 ecd8f800 00001090
[ 1514.174926] 7e80: ecd8f940 ecd8f800 00000000 c068dc60 00000000 00000001 ed0e0800 ecd8f800
[ 1514.183563] 7ea0: 00000000 c06feaa8 c0ca39c2 beea57dc 00000020 00000000 306f7368 00000000
[ 1514.192169] 7ec0: 00000000 00000000 00001091 00000000 00000000 00000000 00000000 00008914
[ 1514.200805] 7ee0: eaa9ab60 beea57dc c0c9bfc0 eaa9ab40 00000006 00000000 00046858 c066a948
[ 1514.209411] 7f00: beea57dc eaa9ab60 ecc6b0c0 c02837b0 00000006 c0282c90 0000c000 c0283654
[ 1514.218017] 7f20: c09b0c00 c098bc31 00000001 c0c5e513 c0c5e513 00000000 c0151354 c01a20c0
[ 1514.226654] 7f40: c0c5e513 c01a3134 ecdd6000 c01a3160 ee7487f0 600f0013 00000000 ee748240
[ 1514.235260] 7f60: ee748734 00000000 ecc6b0c0 ecc6b0c0 beea57dc 00008914 00000006 00000000
[ 1514.243896] 7f80: 00046858 c02837b0 00001091 0003a1f0 00046608 0003a248 00000036 c01071e4
[ 1514.252502] 7fa0: ecdd6000 c0107040 0003a1f0 00046608 00000006 00008914 beea57dc 00001091
[ 1514.261108] 7fc0: 0003a1f0 00046608 0003a248 00000036 0003ac0c 00046608 00046610 00046858
[ 1514.269744] 7fe0: 0003a0ac beea57d4 000167eb b6f23106 400f0030 00000006 00000000 00000000
[ 1514.278411] [<bf79c304>] (hso_start_net_device [hso]) from [<bf79ced8>] (hso_net_open+0x68/0x84 [hso])
[ 1514.288238] [<bf79ced8>] (hso_net_open [hso]) from [<c068d958>] (__dev_open+0xa0/0xf4)
[ 1514.296600] [<c068d958>] (__dev_open) from [<c068dba4>] (__dev_change_flags+0x8c/0x130)
[ 1514.305023] [<c068dba4>] (__dev_change_flags) from [<c068dc60>] (dev_change_flags+0x18/0x48)
[ 1514.313934] [<c068dc60>] (dev_change_flags) from [<c06feaa8>] (devinet_ioctl+0x348/0x714)
[ 1514.322540] [<c06feaa8>] (devinet_ioctl) from [<c066a948>] (sock_ioctl+0x2b0/0x308)
[ 1514.330627] [<c066a948>] (sock_ioctl) from [<c0282c90>] (vfs_ioctl+0x20/0x34)
[ 1514.338165] [<c0282c90>] (vfs_ioctl) from [<c0283654>] (do_vfs_ioctl+0x82c/0x93c)
[ 1514.346038] [<c0283654>] (do_vfs_ioctl) from [<c02837b0>] (SyS_ioctl+0x4c/0x74)
[ 1514.353759] [<c02837b0>] (SyS_ioctl) from [<c0107040>] (ret_fast_syscall+0x0/0x1c)
[ 1514.361755] Code: e3822103 e3822080 e1822781 e5981014 (e5832030)
[ 1514.510833] ---[ end trace dfb3e53c657f34a0 ]---

Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
MSe1969 pushed a commit that referenced this pull request Aug 25, 2022
commit 5ec0811d30378ae104f250bfc9b3640242d81e3f upstream.

When the first propgated copy was a slave the following oops would result:
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
> IP: [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0
> PGD bacd4067 PUD bac66067 PMD 0
> Oops: 0000 [#1] SMP
> Modules linked in:
> CPU: 1 PID: 824 Comm: mount Not tainted 4.6.0-rc5userns+ #1523
> Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
> task: ffff8800bb0a8000 ti: ffff8800bac3c000 task.ti: ffff8800bac3c000
> RIP: 0010:[<ffffffff811fba4e>]  [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0
> RSP: 0018:ffff8800bac3fd38  EFLAGS: 00010283
> RAX: 0000000000000000 RBX: ffff8800bb77ec00 RCX: 0000000000000010
> RDX: 0000000000000000 RSI: ffff8800bb58c000 RDI: ffff8800bb58c480
> RBP: ffff8800bac3fd48 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000001ca1 R11: 0000000000001c9d R12: 0000000000000000
> R13: ffff8800ba713800 R14: ffff8800bac3fda0 R15: ffff8800bb77ec00
> FS:  00007f3c0cd9b7e0(0000) GS:ffff8800bfb00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000010 CR3: 00000000bb79d000 CR4: 00000000000006e0
> Stack:
>  ffff8800bb77ec00 0000000000000000 ffff8800bac3fd88 ffffffff811fbf85
>  ffff8800bac3fd98 ffff8800bb77f080 ffff8800ba713800 ffff8800bb262b40
>  0000000000000000 0000000000000000 ffff8800bac3fdd8 ffffffff811f1da0
> Call Trace:
>  [<ffffffff811fbf85>] propagate_mnt+0x105/0x140
>  [<ffffffff811f1da0>] attach_recursive_mnt+0x120/0x1e0
>  [<ffffffff811f1ec3>] graft_tree+0x63/0x70
>  [<ffffffff811f1f6b>] do_add_mount+0x9b/0x100
>  [<ffffffff811f2c1a>] do_mount+0x2aa/0xdf0
>  [<ffffffff8117efbe>] ? strndup_user+0x4e/0x70
>  [<ffffffff811f3a45>] SyS_mount+0x75/0xc0
>  [<ffffffff8100242b>] do_syscall_64+0x4b/0xa0
>  [<ffffffff81988f3c>] entry_SYSCALL64_slow_path+0x25/0x25
> Code: 00 00 75 ec 48 89 0d 02 22 22 01 8b 89 10 01 00 00 48 89 05 fd 21 22 01 39 8e 10 01 00 00 0f 84 e0 00 00 00 48 8b 80 d8 00 00 00 <48> 8b 50 10 48 89 05 df 21 22 01 48 89 15 d0 21 22 01 8b 53 30
> RIP  [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0
>  RSP <ffff8800bac3fd38>
> CR2: 0000000000000010
> ---[ end trace 2725ecd95164f217 ]---

This oops happens with the namespace_sem held and can be triggered by
non-root users.  An all around not pleasant experience.

To avoid this scenario when finding the appropriate source mount to
copy stop the walk up the mnt_master chain when the first source mount
is encountered.

Further rewrite the walk up the last_source mnt_master chain so that
it is clear what is going on.

The reason why the first source mount is special is that it it's
mnt_parent is not a mount in the dest_mnt propagation tree, and as
such termination conditions based up on the dest_mnt mount propgation
tree do not make sense.

To avoid other kinds of confusion last_dest is not changed when
computing last_source.  last_dest is only used once in propagate_one
and that is above the point of the code being modified, so changing
the global variable is meaningless and confusing.

fixes: f2ebb3a921c1ca1e2ddd9242e95a1989a50c4c68 ("smarter propagate_mnt()")
Reported-by: Tycho Andersen <tycho.andersen@canonical.com>
Reviewed-by: Seth Forshee <seth.forshee@canonical.com>
Tested-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: Ie55a2c52db9773b461acc6ebe427221acb7093f0
MSe1969 pushed a commit that referenced this pull request Aug 20, 2023
commit 48fb6f4db940e92cfb16cd878cddd59ea6120d06 upstream.

Commit 65d8fc777f6d ("futex: Remove requirement for lock_page() in
get_futex_key()") removed an unnecessary lock_page() with the
side-effect that page->mapping needed to be treated very carefully.

Two defensive warnings were added in case any assumption was missed and
the first warning assumed a correct application would not alter a
mapping backing a futex key.  Since merging, it has not triggered for
any unexpected case but Mark Rutland reported the following bug
triggering due to the first warning.

  kernel BUG at kernel/futex.c:679!
  Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 3695 Comm: syz-executor1 Not tainted 4.13.0-rc3-00020-g307fec773ba3 #3
  Hardware name: linux,dummy-virt (DT)
  task: ffff80001e271780 task.stack: ffff000010908000
  PC is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
  LR is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
  pc : [<ffff00000821ac14>] lr : [<ffff00000821ac14>] pstate: 80000145

The fact that it's a bug instead of a warning was due to an unrelated
arm64 problem, but the warning itself triggered because the underlying
mapping changed.

This is an application issue but from a kernel perspective it's a
recoverable situation and the warning is unnecessary so this patch
removes the warning.  The warning may potentially be triggered with the
following test program from Mark although it may be necessary to adjust
NR_FUTEX_THREADS to be a value smaller than the number of CPUs in the
system.

    #include <linux/futex.h>
    #include <pthread.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <sys/mman.h>
    #include <sys/syscall.h>
    #include <sys/time.h>
    #include <unistd.h>

    #define NR_FUTEX_THREADS 16
    pthread_t threads[NR_FUTEX_THREADS];

    void *mem;

    #define MEM_PROT  (PROT_READ | PROT_WRITE)
    #define MEM_SIZE  65536

    static int futex_wrapper(int *uaddr, int op, int val,
                             const struct timespec *timeout,
                             int *uaddr2, int val3)
    {
        syscall(SYS_futex, uaddr, op, val, timeout, uaddr2, val3);
    }

    void *poll_futex(void *unused)
    {
        for (;;) {
            futex_wrapper(mem, FUTEX_CMP_REQUEUE_PI, 1, NULL, mem + 4, 1);
        }
    }

    int main(int argc, char *argv[])
    {
        int i;

        mem = mmap(NULL, MEM_SIZE, MEM_PROT,
               MAP_SHARED | MAP_ANONYMOUS, -1, 0);

        printf("Mapping @ %p\n", mem);

        printf("Creating futex threads...\n");

        for (i = 0; i < NR_FUTEX_THREADS; i++)
            pthread_create(&threads[i], NULL, poll_futex, NULL);

        printf("Flipping mapping...\n");
        for (;;) {
            mmap(mem, MEM_SIZE, MEM_PROT,
                 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS, -1, 0);
        }

        return 0;
    }

Change-Id: I52f642cfcd3e109e6d69bdb1ca17950e6e251dfc
Reported-and-tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kevin F. Haggerty <haggertk@lineageos.org>
MSe1969 pushed a commit that referenced this pull request Aug 22, 2023
commit 48fb6f4db940e92cfb16cd878cddd59ea6120d06 upstream.

Commit 65d8fc777f6d ("futex: Remove requirement for lock_page() in
get_futex_key()") removed an unnecessary lock_page() with the
side-effect that page->mapping needed to be treated very carefully.

Two defensive warnings were added in case any assumption was missed and
the first warning assumed a correct application would not alter a
mapping backing a futex key.  Since merging, it has not triggered for
any unexpected case but Mark Rutland reported the following bug
triggering due to the first warning.

  kernel BUG at kernel/futex.c:679!
  Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 0 PID: 3695 Comm: syz-executor1 Not tainted 4.13.0-rc3-00020-g307fec773ba3 #3
  Hardware name: linux,dummy-virt (DT)
  task: ffff80001e271780 task.stack: ffff000010908000
  PC is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
  LR is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
  pc : [<ffff00000821ac14>] lr : [<ffff00000821ac14>] pstate: 80000145

The fact that it's a bug instead of a warning was due to an unrelated
arm64 problem, but the warning itself triggered because the underlying
mapping changed.

This is an application issue but from a kernel perspective it's a
recoverable situation and the warning is unnecessary so this patch
removes the warning.  The warning may potentially be triggered with the
following test program from Mark although it may be necessary to adjust
NR_FUTEX_THREADS to be a value smaller than the number of CPUs in the
system.

    #include <linux/futex.h>
    #include <pthread.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <sys/mman.h>
    #include <sys/syscall.h>
    #include <sys/time.h>
    #include <unistd.h>

    #define NR_FUTEX_THREADS 16
    pthread_t threads[NR_FUTEX_THREADS];

    void *mem;

    #define MEM_PROT  (PROT_READ | PROT_WRITE)
    #define MEM_SIZE  65536

    static int futex_wrapper(int *uaddr, int op, int val,
                             const struct timespec *timeout,
                             int *uaddr2, int val3)
    {
        syscall(SYS_futex, uaddr, op, val, timeout, uaddr2, val3);
    }

    void *poll_futex(void *unused)
    {
        for (;;) {
            futex_wrapper(mem, FUTEX_CMP_REQUEUE_PI, 1, NULL, mem + 4, 1);
        }
    }

    int main(int argc, char *argv[])
    {
        int i;

        mem = mmap(NULL, MEM_SIZE, MEM_PROT,
               MAP_SHARED | MAP_ANONYMOUS, -1, 0);

        printf("Mapping @ %p\n", mem);

        printf("Creating futex threads...\n");

        for (i = 0; i < NR_FUTEX_THREADS; i++)
            pthread_create(&threads[i], NULL, poll_futex, NULL);

        printf("Flipping mapping...\n");
        for (;;) {
            mmap(mem, MEM_SIZE, MEM_PROT,
                 MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS, -1, 0);
        }

        return 0;
    }

Change-Id: I52f642cfcd3e109e6d69bdb1ca17950e6e251dfc
Reported-and-tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kevin F. Haggerty <haggertk@lineageos.org>
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