INFO: task kworker/u4:8:29677 blocked for more than 143 seconds. Not tainted 5.15.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:8 state:D stack:27720 pid:29677 ppid: 2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6250 schedule+0xd2/0x260 kernel/sched/core.c:6323 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6382 __mutex_lock_common kernel/locking/mutex.c:680 [inline] __mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:740 io_uring_try_cancel_iowq fs/io_uring.c:9617 [inline] io_uring_try_cancel_requests+0x124/0x6f9 fs/io_uring.c:9647 io_ring_exit_work+0xff/0xbe8 fs/io_uring.c:9445 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 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: ffffffff8b983a20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6461 1 lock held by in:imklog/6169: 2 locks held by agetty/6393: #0: ffff888078ba3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffffc90002a6c2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113 2 locks held by agetty/6395: #0: ffff8880123d1098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffffc90002a182e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113 3 locks held by kworker/u4:8/29677: #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269 #1: ffffc9000ad97db0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 #2: ffff888087a4c0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_uring_try_cancel_iowq fs/io_uring.c:9617 [inline] #2: ffff888087a4c0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_uring_try_cancel_requests+0x124/0x6f9 fs/io_uring.c:9647 3 locks held by syz-executor.1/30738: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-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+0x405/0x4f0 kernel/kthread.c:327 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: 30738 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:unwind_next_frame+0xeb8/0x1ce0 arch/x86/kernel/unwind_orc.c:616 Code: 0f 84 10 f5 ff ff 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 90 0a 00 00 41 3b 2e <0f> 84 b9 05 00 00 bf 01 00 00 00 e8 88 ef 1b 00 b8 01 00 00 00 65 RSP: 0018:ffffc90003a67810 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff9200074cf0a RCX: 1ffff9200074cf25 RDX: 1ffff9200074cf1d RSI: ffffc90003a67f30 RDI: ffffc90003a67f30 RBP: 0000000000000001 R08: ffffffff8e81fbe8 R09: 0000000000000001 R10: fffff5200074cf28 R11: 0000000000086089 R12: ffffc90003a67f40 R13: ffffc90003a6791d R14: ffffc90003a678e8 R15: ffffc90003a6791c FS: 00007f5cfc6e5700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7d3ec2a000 CR3: 0000000027461000 CR4: 0000000000350ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:590 [inline] io_add_buffers fs/io_uring.c:4405 [inline] io_provide_buffers fs/io_uring.c:4439 [inline] io_issue_sqe+0x2887/0x7010 fs/io_uring.c:6705 __io_queue_sqe fs/io_uring.c:6978 [inline] io_req_task_submit+0xce/0x450 fs/io_uring.c:2282 tctx_task_work+0x1b3/0x630 fs/io_uring.c:2206 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 tracehook_notify_signal include/linux/tracehook.h:214 [inline] handle_signal_work kernel/entry/common.c:146 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x256/0x290 kernel/entry/common.c:207 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f5cff16fae9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5cfc6e5188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: 00000000000002ff RBX: 00007f5cff282f60 RCX: 00007f5cff16fae9 RDX: 0000000000000000 RSI: 00000000000002ff RDI: 0000000000000003 RBP: 00007f5cff1c9f25 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdcc7fbe6f R14: 00007f5cfc6e5300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 0f 84 10 f5 ff ff je 0xfffff516 6: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax d: fc ff df 10: 4c 89 f2 mov %r14,%rdx 13: 48 c1 ea 03 shr $0x3,%rdx 17: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax 1b: 84 c0 test %al,%al 1d: 74 08 je 0x27 1f: 3c 03 cmp $0x3,%al 21: 0f 8e 90 0a 00 00 jle 0xab7 27: 41 3b 2e cmp (%r14),%ebp * 2a: 0f 84 b9 05 00 00 je 0x5e9 <-- trapping instruction 30: bf 01 00 00 00 mov $0x1,%edi 35: e8 88 ef 1b 00 callq 0x1befc2 3a: b8 01 00 00 00 mov $0x1,%eax 3f: 65 gs