INFO: task syz-executor.4:23042 blocked for more than 143 seconds. Not tainted 5.11.0-rc5-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:29016 pid:23042 ppid: 8510 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1854 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x163/0x260 kernel/sched/completion.c:138 kthread_park+0x122/0x1b0 kernel/kthread.c:582 io_sq_thread_park fs/io_uring.c:7462 [inline] io_sq_thread_park fs/io_uring.c:7456 [inline] io_uring_cancel_task_requests fs/io_uring.c:8963 [inline] __io_uring_files_cancel+0x3bd/0x10e0 fs/io_uring.c:9058 io_uring_files_cancel include/linux/io_uring.h:51 [inline] do_exit+0x2fe/0x2ae0 kernel/exit.c:780 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x427/0x20f0 kernel/signal.c:2773 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 RSP: 002b:00007f23a8f1ac68 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: 0000000000000003 RBX: 0000000000000002 RCX: 000000000045e219 RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000000004460 RBP: 000000000119bfb8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffdb21d36ef R14: 00007f23a8f1b9c0 R15: 000000000119bf8c Showing all locks held in the system: 1 lock held by khungtaskd/1657: #0: ffffffff8b373ce0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6259 1 lock held by in:imklog/8365: #0: ffff888011e0c870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 3 locks held by kworker/u4:0/12363: 1 lock held by syz-executor.4/23042: #0: ffff888022d55070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_park fs/io_uring.c:7461 [inline] #0: ffff888022d55070 (&sqd->lock){+.+.}-{3:3}, at: io_sq_thread_park fs/io_uring.c:7456 [inline] #0: ffff888022d55070 (&sqd->lock){+.+.}-{3:3}, at: io_uring_cancel_task_requests fs/io_uring.c:8963 [inline] #0: ffff888022d55070 (&sqd->lock){+.+.}-{3:3}, at: __io_uring_files_cancel+0x39f/0x10e0 fs/io_uring.c:9058 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1657 Comm: khungtaskd Not tainted 5.11.0-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:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 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:209 [inline] watchdog+0xd43/0xfa0 kernel/hung_task.c:294 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4890 Comm: systemd-journal Not tainted 5.11.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:desc_read+0x17e/0x350 kernel/printk/printk_ringbuffer.c:480 Code: 48 8d 7d 08 e8 03 1c 5a 00 48 83 3c 24 00 74 46 e8 37 56 17 00 4c 89 fa 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 a7 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 4d 8b RSP: 0018:ffffc9000164fa98 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff8b3511b8 RCX: 0000000000000000 RDX: 1ffffffff165e3bb RSI: ffffffff815b6ab9 RDI: ffffc9000164fc68 RBP: ffffc9000164fc50 R08: 0000000000000001 R09: ffffc9000164fc67 R10: fffff520002c9f8c R11: 0000000000000001 R12: 0000000100001431 R13: 8000000100001431 R14: 0000000000000002 R15: ffffffff8b2f1dd8 FS: 00007fbe04e9e8c0(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbe01cca000 CR3: 0000000010f5b000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: desc_read_finalized_seq+0x81/0x1c0 kernel/printk/printk_ringbuffer.c:1752 prb_read kernel/printk/printk_ringbuffer.c:1800 [inline] _prb_read_valid+0x1cd/0x710 kernel/printk/printk_ringbuffer.c:1880 prb_read_valid+0x75/0xa0 kernel/printk/printk_ringbuffer.c:1929 devkmsg_read+0x13f/0x740 kernel/printk/printk.c:723 vfs_read+0x1b5/0x570 fs/read_write.c:494 ksys_read+0x12d/0x250 fs/read_write.c:634 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fbe0442e210 Code: 73 01 c3 48 8b 0d 98 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 c1 20 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 RSP: 002b:00007fff55634f48 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fff556379c0 RCX: 00007fbe0442e210 RDX: 0000000000002000 RSI: 00007fff556357c0 RDI: 0000000000000009 RBP: 0000000000000000 R08: 0000000000000008 R09: 00007fff556740f0 R10: 0000000000066a04 R11: 0000000000000246 R12: 00007fff556357c0 R13: 00007fff55637918 R14: 00005639958fa958 R15: 0005b9bae97f5f02