INFO: task kworker/u4:9:1478 blocked for more than 143 seconds. Not tainted 5.15.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:9 state:D stack:24856 pid: 1478 ppid: 2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425 __mutex_lock_common kernel/locking/mutex.c:669 [inline] __mutex_lock+0xa34/0x12f0 kernel/locking/mutex.c:729 io_uring_try_cancel_iowq fs/io_uring.c:9529 [inline] io_uring_try_cancel_requests+0x7d1/0xc30 fs/io_uring.c:9559 io_ring_exit_work+0x137/0x1980 fs/io_uring.c:9359 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8b97d460 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by in:imklog/6230: #0: ffff88801b5a9b30 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 3 locks held by kworker/u4:9/1478: #0: ffff888010c74138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c74138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c74138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c74138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline] #0: ffff888010c74138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline] #0: ffff888010c74138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x8a3/0x16b0 kernel/workqueue.c:2268 #1: ffffc900033d7db0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8d7/0x16b0 kernel/workqueue.c:2272 #2: ffff8880135ee0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_uring_try_cancel_iowq fs/io_uring.c:9529 [inline] #2: ffff8880135ee0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_uring_try_cancel_requests+0x7d1/0xc30 fs/io_uring.c:9559 1 lock held by syz-executor.2/8403: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc2-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:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22987 Comm: kworker/u4:8 Not tainted 5.15.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:strlen+0x3f/0x90 lib/string.c:566 Code: 53 48 83 ec 08 0f b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 48 80 7d 00 00 74 39 48 bb 00 00 00 00 00 fc ff df 48 89 e8 <48> 83 c0 01 48 89 c2 48 89 c1 48 c1 ea 03 83 e1 07 0f b6 14 1a 38 RSP: 0018:ffffc9000b5cf8c0 EFLAGS: 00000002 RAX: ffffffff89e3ad46 RBX: dffffc0000000000 RCX: 0000000000000006 RDX: 0000000000000000 RSI: ffffffff904be808 RDI: ffffffff89e3ad40 RBP: ffffffff89e3ad40 R08: 0000000000000000 R09: ffffffff8d6e1857 R10: fffffbfff1adc30a R11: 0000000000000000 R12: ffffffff904be808 R13: ffffffff8b87a7a0 R14: ffffffff904be808 R15: ffffc9000b5cf990 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c01ca07010 CR3: 000000000b68e000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: strlen include/linux/fortify-string.h:60 [inline] trace_event_get_offsets_lock include/trace/events/lock.h:39 [inline] perf_trace_lock+0xb1/0x4d0 include/trace/events/lock.h:39 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x4a8/0x720 kernel/locking/lockdep.c:5636 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irqrestore+0x16/0x70 kernel/locking/spinlock.c:194 debug_object_activate+0x287/0x3e0 lib/debugobjects.c:689 debug_timer_activate kernel/time/timer.c:729 [inline] __mod_timer+0x77d/0xe30 kernel/time/timer.c:1050 __queue_delayed_work+0x1a7/0x270 kernel/workqueue.c:1677 queue_delayed_work_on+0x105/0x120 kernel/workqueue.c:1702 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: 53 push %rbx 1: 48 83 ec 08 sub $0x8,%rsp 5: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax 9: 48 89 fa mov %rdi,%rdx c: 83 e2 07 and $0x7,%edx f: 38 d0 cmp %dl,%al 11: 7f 04 jg 0x17 13: 84 c0 test %al,%al 15: 75 48 jne 0x5f 17: 80 7d 00 00 cmpb $0x0,0x0(%rbp) 1b: 74 39 je 0x56 1d: 48 bb 00 00 00 00 00 movabs $0xdffffc0000000000,%rbx 24: fc ff df 27: 48 89 e8 mov %rbp,%rax * 2a: 48 83 c0 01 add $0x1,%rax <-- trapping instruction 2e: 48 89 c2 mov %rax,%rdx 31: 48 89 c1 mov %rax,%rcx 34: 48 c1 ea 03 shr $0x3,%rdx 38: 83 e1 07 and $0x7,%ecx 3b: 0f b6 14 1a movzbl (%rdx,%rbx,1),%edx 3f: 38 .byte 0x38