Re: general protection fault in unlink_file_vma

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
kernel panic: corrupted stack end in sys_nanosleep

Kernel panic - not syncing: corrupted stack end detected inside scheduler
CPU: 0 PID: 13791 Comm: syz-executor.4 Not tainted 5.9.0-rc5-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+0x198/0x1fd lib/dump_stack.c:118
 panic+0x347/0x7c0 kernel/panic.c:231
 schedule_debug kernel/sched/core.c:4278 [inline]
 __schedule+0x221e/0x2230 kernel/sched/core.c:4422
 schedule+0xd0/0x2a0 kernel/sched/core.c:4602
 freezable_schedule include/linux/freezer.h:172 [inline]
 do_nanosleep+0x222/0x650 kernel/time/hrtimer.c:1883
 hrtimer_nanosleep+0x1f9/0x430 kernel/time/hrtimer.c:1936
 __do_sys_nanosleep kernel/time/hrtimer.c:1970 [inline]
 __se_sys_nanosleep kernel/time/hrtimer.c:1957 [inline]
 __x64_sys_nanosleep+0x1dc/0x260 kernel/time/hrtimer.c:1957
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45ba81
Code: 75 14 b8 23 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 84 cf fb ff c3 48 83 ec 08 e8 ea 46 00 00 48 89 04 24 b8 23 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 33 47 00 00 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007ffca6cb6d70 EFLAGS: 00000293 ORIG_RAX: 0000000000000023
RAX: ffffffffffffffda RBX: 000000000002f226 RCX: 000000000045ba81
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffca6cb6d80
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 00007ffca6cb6e80 R11: 0000000000000293 R12: 000000000118cf40
R13: 000000000118d940 R14: ffffffffffffffff R15: 000000000118cfec
Kernel Offset: disabled
Rebooting in 86400 seconds..


Tested on:

commit:         796cd8f4 fix gpf
git tree:       https://github.com/Linmiaohe/linux/
console output: https://syzkaller.appspot.com/x/log.txt?x=12b5d501900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f82e58a6661a5ac4
dashboard link: https://syzkaller.appspot.com/bug?extid=c5d5a51dcbb558ca0cb5
compiler:       gcc (GCC) 10.1.0-syz 20200507