syzbot


INFO: task hung in fsnotify_sb_delete

Status: auto-closed as invalid on 2021/10/22 10:01
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 462d, last: 462d

Sample crash report:
INFO: task syz-executor.1:20069 blocked for more than 143 seconds.
      Not tainted 5.14.0-rc6-next-20210820-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1  state:D stack:22224 pid:20069 ppid:     1 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4756 [inline]
 __schedule+0x943/0x2700 kernel/sched/core.c:6029
 schedule+0xd7/0x280 kernel/sched/core.c:6108
 fsnotify_sb_delete+0x3fc/0x4e0 fs/notify/fsnotify.c:97
 generic_shutdown_super+0xb7/0x380 fs/super.c:456
 kill_anon_super fs/super.c:1057 [inline]
 kill_litter_super+0x6e/0xa0 fs/super.c:1066
 deactivate_locked_super+0x94/0x160 fs/super.c:335
 deactivate_super+0xb5/0xe0 fs/super.c:366
 cleanup_mnt+0x3a3/0x540 fs/namespace.c:1137
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x467a47
RSP: 002b:00007fffb47ca4a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000467a47
RDX: 00007fffb47ca57a RSI: 0000000000000002 RDI: 00007fffb47ca570
RBP: 00007fffb47ca570 R08: 00000000ffffffff R09: 00007fffb47ca340
R10: 00000000020bf8e3 R11: 0000000000000246 R12: 00000000004bee90
R13: 00007fffb47cb640 R14: 00000000020bf810 R15: 00007fffb47cb680
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.14.0-rc6-next-20210820-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:254 [inline]
 watchdog+0xccb/0xef0 kernel/hung_task.c:339
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2964 Comm: systemd-journal Not tainted 5.14.0-rc6-next-20210820-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:49 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:342 [inline]
RIP: 0010:deref_stack_reg+0x81/0x160 arch/x86/kernel/unwind_orc.c:352
Code: 85 c3 00 00 00 49 8d 7c 24 10 4d 8b 6c 24 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 94 00 00 00 <49> 39 ed 49 8b 44 24 10 77 13 48 39 e8 76 0e 48 8d 55 08 48 39 d0
RSP: 0018:ffffc900024cf598 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffc900024cf700 RCX: 0000000000000000
RDX: 1ffff92000499eda RSI: ffffc900024cfa38 RDI: ffffc900024cf6d0
RBP: ffffc900024cfa38 R08: ffffffff8df2260c R09: 0000000000000001
R10: fffff52000499ee3 R11: 0000000000086089 R12: ffffc900024cf6c0
R13: ffffc900024c8000 R14: ffffc900024cf6c0 R15: ffffc900024cf6f4
FS:  00007fe935a628c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe9326cec00 CR3: 000000001c8a2000 CR4: 00000000001526e0
Call Trace:
 unwind_next_frame+0x13e0/0x1ce0 arch/x86/kernel/unwind_orc.c:587
 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:121
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_record_aux_stack+0xed/0x120 mm/kasan/generic.c:348
 task_work_add+0x3a/0x190 kernel/task_work.c:38
 fput_many.part.0+0xbb/0x170 fs/file_table.c:341
 fput_many fs/file_table.c:336 [inline]
 fput+0x3f/0x50 fs/file_table.c:357
 path_openat+0x1a56/0x28b0 fs/namei.c:3570
 do_filp_open+0x1aa/0x400 fs/namei.c:3588
 do_sys_openat2+0x16d/0x4e0 fs/open.c:1204
 do_sys_open fs/open.c:1220 [inline]
 __do_sys_open fs/open.c:1228 [inline]
 __se_sys_open fs/open.c:1224 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1224
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fe934ff1840
Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24
RSP: 002b:00007ffc62a2cb78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007ffc62a2ce80 RCX: 00007fe934ff1840
RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 00005606b14324c0
RBP: 000000000000000d R08: 000000000000ffc0 R09: 00000000ffffffff
R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00005606b1425040 R14: 00007ffc62a2ce40 R15: 00005606b14322e0
----------------
Code disassembly (best guess):
   0:	85 c3                	test   %eax,%ebx
   2:	00 00                	add    %al,(%rax)
   4:	00 49 8d             	add    %cl,-0x73(%rcx)
   7:	7c 24                	jl     0x2d
   9:	10 4d 8b             	adc    %cl,-0x75(%rbp)
   c:	6c                   	insb   (%dx),%es:(%rdi)
   d:	24 08                	and    $0x8,%al
   f:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  16:	fc ff df
  19:	48 89 fa             	mov    %rdi,%rdx
  1c:	48 c1 ea 03          	shr    $0x3,%rdx
  20:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
  24:	0f 85 94 00 00 00    	jne    0xbe
* 2a:	49 39 ed             	cmp    %rbp,%r13 <-- trapping instruction
  2d:	49 8b 44 24 10       	mov    0x10(%r12),%rax
  32:	77 13                	ja     0x47
  34:	48 39 e8             	cmp    %rbp,%rax
  37:	76 0e                	jbe    0x47
  39:	48 8d 55 08          	lea    0x8(%rbp),%rdx
  3d:	48 39 d0             	cmp    %rdx,%rax

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-linux-next-kasan-gce-root 2021/08/23 09:54 linux-next 86ed57fd8c93 b599f2fc .config log report info INFO: task hung in fsnotify_sb_delete
* Struck through repros no longer work on HEAD.