syzbot


general protection fault in posix_cpu_timers_exit

Status: auto-closed as invalid on 2022/04/12 13:57
Reported-by: syzbot+cbeb81c714c8beb718ae@syzkaller.appspotmail.com
First crash: 1086d, last: 1086d

Sample crash report:
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 21005 Comm: syz-executor.5 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:cleanup_timers_list kernel/time/posix-cpu-timers.c:411 [inline]
RIP: 0010:cleanup_timers kernel/time/posix-cpu-timers.c:425 [inline]
RIP: 0010:posix_cpu_timers_exit+0x2f3/0x5d0 kernel/time/posix-cpu-timers.c:435
Code: 80 3c 02 00 0f 85 a2 02 00 00 48 8b 44 24 08 48 8b 98 80 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 49 89 df 48 c1 ea 03 <80> 3c 02 00 0f 85 86 02 00 00 48 bd 00 00 00 00 00 fc ff df 48 39
RSP: 0018:ffff88809778fa18 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff814bdebb
RDX: 0000000000000000 RSI: ffffffff81567979 RDI: ffff888000160400
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffed1012728bc9
R10: ffff888093945e4b R11: 0000000000000000 R12: ffff888000160a70
R13: dffffc0000000000 R14: ffff888000160a70 R15: 0000000000000000
FS:  00007fd07f068700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c55bc04118 CR3: 000000002a0b2000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __exit_signal kernel/exit.c:104 [inline]
 release_task+0x2e0/0x1480 kernel/exit.c:201
 exit_notify kernel/exit.c:745 [inline]
 do_exit+0x15be/0x2be0 kernel/exit.c:890
 do_group_exit+0x125/0x310 kernel/exit.c:967
 get_signal+0x3f2/0x1f70 kernel/signal.c:2589
 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799
 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fd0806f2e99
Code: Bad RIP value.
RSP: 002b:00007fd07f068218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fd080805f68 RCX: 00007fd0806f2e99
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd080805f68
RBP: 00007fd080805f60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd080805f6c
R13: 00007ffe0e12bb4f R14: 00007fd07f068300 R15: 0000000000022000
Modules linked in:
---[ end trace 051a38b37857041e ]---
RIP: 0010:cleanup_timers_list kernel/time/posix-cpu-timers.c:411 [inline]
RIP: 0010:cleanup_timers kernel/time/posix-cpu-timers.c:425 [inline]
RIP: 0010:posix_cpu_timers_exit+0x2f3/0x5d0 kernel/time/posix-cpu-timers.c:435
Code: 80 3c 02 00 0f 85 a2 02 00 00 48 8b 44 24 08 48 8b 98 80 06 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 49 89 df 48 c1 ea 03 <80> 3c 02 00 0f 85 86 02 00 00 48 bd 00 00 00 00 00 fc ff df 48 39
RSP: 0018:ffff88809778fa18 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff814bdebb
RDX: 0000000000000000 RSI: ffffffff81567979 RDI: ffff888000160400
RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffed1012728bc9
R10: ffff888093945e4b R11: 0000000000000000 R12: ffff888000160a70
R13: dffffc0000000000 R14: ffff888000160a70 R15: 0000000000000000
FS:  00007fd07f068700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd0806f2e6f CR3: 000000002a0b2000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   4:	0f 85 a2 02 00 00    	jne    0x2ac
   a:	48 8b 44 24 08       	mov    0x8(%rsp),%rax
   f:	48 8b 98 80 06 00 00 	mov    0x680(%rax),%rbx
  16:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1d:	fc ff df
  20:	48 89 da             	mov    %rbx,%rdx
  23:	49 89 df             	mov    %rbx,%r15
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 86 02 00 00    	jne    0x2ba
  34:	48 bd 00 00 00 00 00 	movabs $0xdffffc0000000000,%rbp
  3b:	fc ff df
  3e:	48                   	rex.W
  3f:	39                   	.byte 0x39

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/12/13 13:56 linux-4.19.y 3f8a27f9e27b 0304899b .config console log report info ci2-linux-4-19 general protection fault in posix_cpu_timers_exit
* Struck through repros no longer work on HEAD.