kernel panic: corrupted stack end in sys_inotify_rm_watch

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 3c40cdb0 Merge branch 'linus' of git://git.kernel.org/pub/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1569bbd4100000
kernel config: https://syzkaller.appspot.com/x/.config?x=b0212dbee046bc1f
dashboard link: https://syzkaller.appspot.com/bug?extid=d431c5982fbe4f84ed54
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [amir...@gmail.com ja...@suse.cz linux-...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d431c5...@syzkaller.appspotmail.com

Kernel panic - not syncing: corrupted stack end detected inside scheduler
CPU: 1 PID: 23929 Comm: systemd-udevd Not tainted 5.7.0-rc4-syzkaller #0
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+0x188/0x20d lib/dump_stack.c:118
panic+0x2e3/0x75c kernel/panic.c:221
schedule_debug kernel/sched/core.c:3879 [inline]
__schedule+0x1fe0/0x1ff0 kernel/sched/core.c:4013
preempt_schedule_common+0x4a/0xc0 kernel/sched/core.c:4239
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:50
__raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:183
spin_unlock include/linux/spinlock.h:393 [inline]
fsnotify_put_mark+0x2e8/0x580 fs/notify/mark.c:275
__do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:790 [inline]
__se_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:762 [inline]
__x64_sys_inotify_rm_watch+0x11d/0x190 fs/notify/inotify/inotify_user.c:762
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x7f69229de427
Code: 73 01 c3 48 8b 0d 71 fa 2a 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 ff 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 41 fa 2a 00 f7 d8 64 89 01 48
RSP: 002b:00007ffc0be45868 EFLAGS: 00000246 ORIG_RAX: 00000000000000ff
RAX: ffffffffffffffda RBX: 0000563a386fecb0 RCX: 00007f69229de427
RDX: 0000000000000007 RSI: 000000000000084e RDI: 0000000000000009
RBP: 000000000000084e R08: 0000563a38708d40 R09: 0000000000000020
R10: 39db172e334a3d76 R11: 0000000000000246 R12: 00007ffc0be45980
R13: 0000563a386fecb0 R14: 0000000000000003 R15: 000000000000000e
Kernel Offset: disabled
Rebooting in 86400 seconds..


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.