syzbot


WARNING in ep_poll (2)

Status: upstream: reported C repro on 2022/11/30 22:43
Reported-by: syzbot+040b317810fd3e21b55d@syzkaller.appspotmail.com
First crash: 70d, last: 24d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in ep_poll 4 1326d 1518d 0/24 auto-closed as invalid on 2019/10/25 08:50

Sample crash report:
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 0 PID: 4411 at kernel/locking/mutex.c:582 __mutex_lock_common+0x4c4/0xca8 kernel/locking/mutex.c:582
Modules linked in:
CPU: 0 PID: 4411 Comm: udevd Not tainted 6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __mutex_lock_common+0x4c4/0xca8 kernel/locking/mutex.c:582
lr : __mutex_lock_common+0x4c4/0xca8 kernel/locking/mutex.c:582
sp : ffff80000ff93b30
x29: ffff80000ff93ba0 x28: ffff80000f068000 x27: ffff0000cb02b940
x26: 0000000000000000 x25: ffff0000c609ce00 x24: 0000000000000002
x23: ffff80000867f530 x22: 0000000000000000 x21: 0000000000000000
x20: 0000000000000000 x19: ffff0000cb02b800 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000012 x12: ffff80000dadbaa0
x11: ff808000081cbbc8 x10: 0000000000000000 x9 : 52d299f931448700
x8 : 52d299f931448700 x7 : 4e5241575f534b43 x6 : ffff80000c11ee8c
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000000 x1 : 0000000100000000 x0 : 0000000000000028
Call trace:
 __mutex_lock_common+0x4c4/0xca8 kernel/locking/mutex.c:582
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 ep_send_events fs/eventpoll.c:1657 [inline]
 ep_poll+0x320/0xc70 fs/eventpoll.c:1823
 do_epoll_wait+0x144/0x18c fs/eventpoll.c:2258
 do_epoll_pwait fs/eventpoll.c:2292 [inline]
 __do_sys_epoll_pwait+0x110/0x214 fs/eventpoll.c:2305
 __se_sys_epoll_pwait fs/eventpoll.c:2299 [inline]
 __arm64_sys_epoll_pwait+0x30/0x40 fs/eventpoll.c:2299
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
 el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
irq event stamp: 157433
hardirqs last  enabled at (157433): [<ffff800008038bd8>] local_daif_restore arch/arm64/include/asm/daifflags.h:75 [inline]
hardirqs last  enabled at (157433): [<ffff800008038bd8>] el0_svc_common+0x40/0x220 arch/arm64/kernel/syscall.c:107
hardirqs last disabled at (157432): [<ffff80000c111220>] el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
softirqs last  enabled at (156924): [<ffff80000801c86c>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (156922): [<ffff80000801c838>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
Mem abort info:
  ESR = 0x0000000096000044
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x04: level 0 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000044
  CM = 0, WnR = 1
user pgtable: 4k pages, 48-bit VAs, pgdp=000000010cbcf000
[0000000000000008] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000096000044 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 4411 Comm: udevd Tainted: G        W          6.2.0-rc3-syzkaller-16369-g358a161a6a9e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __list_splice include/linux/list.h:449 [inline]
pc : list_splice_init include/linux/list.h:491 [inline]
pc : ep_start_scan+0x13c/0x1b4 fs/eventpoll.c:624
lr : list_splice_init include/linux/list.h:491 [inline]
lr : ep_start_scan+0x134/0x1b4 fs/eventpoll.c:624
sp : ffff80000ff93bd0
x29: ffff80000ff93bd0 x28: ffff80000ff93c78 x27: ffff0000cb02b940
x26: 0000000000000001 x25: ffff0000c609ce00 x24: ffff0000cb02b930
x23: 0000000000000000 x22: ffff0000cb02b930 x21: ffff0000cb02b940
x20: ffff80000ff93c98 x19: ffff0000cb02b800 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000012 x12: ffff80000dadbaa0
x11: ff8080000867df20 x10: 0000000000000000 x9 : 0000000000000000
x8 : ffff80000ff93c98 x7 : 4e5241575f534b43 x6 : ffff80000867df0c
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 00000000000000ff x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 __list_splice include/linux/list.h:447 [inline]
 list_splice_init include/linux/list.h:491 [inline]
 ep_start_scan+0x13c/0x1b4 fs/eventpoll.c:624
 ep_send_events fs/eventpoll.c:1658 [inline]
 ep_poll+0x32c/0xc70 fs/eventpoll.c:1823
 do_epoll_wait+0x144/0x18c fs/eventpoll.c:2258
 do_epoll_pwait fs/eventpoll.c:2292 [inline]
 __do_sys_epoll_pwait+0x110/0x214 fs/eventpoll.c:2305
 __se_sys_epoll_pwait fs/eventpoll.c:2299 [inline]
 __arm64_sys_epoll_pwait+0x30/0x40 fs/eventpoll.c:2299
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
 el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x48/0x140 arch/arm64/kernel/syscall.c:197
 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584
Code: 54000160 97f0c33f f9400288 f9409e69 (f90006f4) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	54000160 	b.eq	0x2c  // b.none
   4:	97f0c33f 	bl	0xffffffffffc30d00
   8:	f9400288 	ldr	x8, [x20]
   c:	f9409e69 	ldr	x9, [x19, #312]
* 10:	f90006f4 	str	x20, [x23, #8] <-- trapping instruction

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci-upstream-gce-arm64 2023/01/12 02:11 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 358a161a6a9e 96166539 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] WARNING in ep_poll
ci-upstream-gce-arm64 2022/11/26 22:41 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 6d464646530f 74a66371 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] WARNING in ep_poll
* Struck through repros no longer work on HEAD.