syzbot


INFO: task hung in io_uring_register

Status: auto-closed as invalid on 2022/04/01 07:34
Reported-by: syzbot+7daefdd84ee7b8170aa6@syzkaller.appspotmail.com
First crash: 363d, last: 363d

Sample crash report:
INFO: task syz-executor.5:3737 blocked for more than 143 seconds.
      Not tainted 5.16.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:29592 pid: 3737 ppid:  7406 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4972 [inline]
 __schedule+0xa9a/0x4940 kernel/sched/core.c:6253
 schedule+0xd2/0x260 kernel/sched/core.c:6326
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6385
 __mutex_lock_common kernel/locking/mutex.c:680 [inline]
 __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:740
 __do_sys_io_uring_register+0x2e0/0x15a0 fs/io_uring.c:11087
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f8f023f9ae9
RSP: 002b:00007f8eff94e188 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab
RAX: ffffffffffffffda RBX: 00007f8f0250d020 RCX: 00007f8f023f9ae9
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000003
RBP: 00007f8f02453f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8f02a40b2f R14: 00007f8eff94e300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffffffff8bb83b60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458
4 locks held by kworker/1:1/35:
 #0: ffff8880b9c39a98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:486 [inline]
 #0: ffff8880b9c39a98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x8c/0x120 kernel/sched/core.c:471
 #1: ffff8880b9d279c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3a6/0x490 kernel/sched/psi.c:880
 #2: ffff8880b9d28298 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:946
 #3: ffffffff9064b2c8 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x12e/0x3e0 lib/debugobjects.c:661
1 lock held by in:imklog/6232:
 #0: ffff88807b8334f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
2 locks held by kworker/u4:11/22134:
1 lock held by syz-executor.5/3735:
1 lock held by syz-executor.5/3737:
 #0: ffff888073e690a8 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_register+0x2e0/0x15a0 fs/io_uring.c:11087
1 lock held by syz-executor.5/3780:
 #0: ffff88807c96d0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_uring_del_tctx_node+0x109/0x20a fs/io_uring.c:9777
1 lock held by syz-executor.5/3782:

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __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:111
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xc1d/0xf50 kernel/hung_task.c:295
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6232 Comm: in:imklog Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__switch_to_asm+0x2a/0x40 arch/x86/entry/entry_64.S:259
Code: 55 53 41 54 41 55 41 56 41 57 48 89 a7 98 17 00 00 48 8b a6 98 17 00 00 48 8b 9e d0 05 00 00 65 48 89 1c 25 28 00 00 00 41 5f <41> 5e 41 5d 41 5c 5b 5d e9 19 97 28 00 66 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90001adfa40 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: 38aea85631ad7d00 RCX: ffffc900081e7930
RDX: 1ffff11017387352 RSI: ffff888017d13a00 RDI: ffff88807f371d00
RBP: ffffc900081e7ac0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 000000000000003f R12: ffff888017d13a00
R13: ffff8880b9c39a80 R14: ffff88807f372218 R15: ffff88801a3abf10
FS:  00007f1dbd29c700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe56da98000 CR3: 0000000018b09000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
----------------
Code disassembly (best guess):
   0:	55                   	push   %rbp
   1:	53                   	push   %rbx
   2:	41 54                	push   %r12
   4:	41 55                	push   %r13
   6:	41 56                	push   %r14
   8:	41 57                	push   %r15
   a:	48 89 a7 98 17 00 00 	mov    %rsp,0x1798(%rdi)
  11:	48 8b a6 98 17 00 00 	mov    0x1798(%rsi),%rsp
  18:	48 8b 9e d0 05 00 00 	mov    0x5d0(%rsi),%rbx
  1f:	65 48 89 1c 25 28 00 	mov    %rbx,%gs:0x28
  26:	00 00
  28:	41 5f                	pop    %r15
* 2a:	41 5e                	pop    %r14 <-- trapping instruction
  2c:	41 5d                	pop    %r13
  2e:	41 5c                	pop    %r12
  30:	5b                   	pop    %rbx
  31:	5d                   	pop    %rbp
  32:	e9 19 97 28 00       	jmpq   0x289750
  37:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
  3e:	00 00

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce 2021/12/02 07:34 upstream 58e1100fdc59 61f86278 .config log report info INFO: task hung in io_uring_register
* Struck through repros no longer work on HEAD.