INFO: task kworker/u4:3:158 blocked for more than 143 seconds. Not tainted 5.15.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:24864 pid: 158 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:9570 [inline] io_uring_try_cancel_requests+0x7d1/0xc30 fs/io_uring.c:9600 io_ring_exit_work+0x137/0x19a0 fs/io_uring.c:9400 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/26: #0: ffffffff8b97fe20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 3 locks held by kworker/u4:3/158: #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:634 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline] #0: ffff888010c69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x8a3/0x16b0 kernel/workqueue.c:2268 #1: ffffc9000204fdb0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8d7/0x16b0 kernel/workqueue.c:2272 #2: ffff88807d7d40a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_uring_try_cancel_iowq fs/io_uring.c:9570 [inline] #2: ffff88807d7d40a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_uring_try_cancel_requests+0x7d1/0xc30 fs/io_uring.c:9600 1 lock held by in:imklog/6387: #0: ffff88801a228870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 1 lock held by syz-executor.2/8442: 2 locks held by syz-executor.2/8460: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 26 Comm: khungtaskd Not tainted 5.15.0-rc4-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: 8442 Comm: syz-executor.2 Not tainted 5.15.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:preempt_count_add+0x4a/0x140 kernel/sched/core.c:5403 Code: c0 03 0f b6 14 11 38 d0 7c 08 84 d2 0f 85 e1 00 00 00 8b 15 38 11 d5 0e 65 01 1d 51 58 b2 7e 85 d2 75 11 65 8b 05 46 58 b2 7e <0f> b6 c0 3d f4 00 00 00 7f 64 65 8b 05 35 58 b2 7e 25 ff ff ff 7f RSP: 0018:ffffc900046bf6f8 EFLAGS: 00000246 RAX: 0000000080000001 RBX: 0000000000000001 RCX: 1ffffffff204951c RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffff8e7f8d92 R09: 0000000000000001 R10: fffff520008d7f08 R11: 0000000000086089 R12: ffffc900046bf830 R13: 0000000000000000 R14: ffffc900046bf7e8 R15: ffff888182f56400 FS: 00007f8ee33fd700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1833b1d020 CR3: 00000000b268d000 CR4: 00000000003506f0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x120/0x1ce0 arch/x86/kernel/unwind_orc.c:428 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_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+0xa4/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:591 [inline] io_add_buffers fs/io_uring.c:4385 [inline] io_provide_buffers fs/io_uring.c:4419 [inline] io_issue_sqe+0x3289/0x7180 fs/io_uring.c:6731 __io_queue_sqe+0x90/0xb50 fs/io_uring.c:6960 io_req_task_submit+0xbf/0x1b0 fs/io_uring.c:2234 tctx_task_work+0x189/0x6c0 fs/io_uring.c:2159 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: 0033:0x7f8ee5e868d9 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:00007f8ee33fd188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: 00000000000002ff RBX: 00007f8ee5f8af60 RCX: 00007f8ee5e868d9 RDX: 0000000000000000 RSI: 00000000000002ff RDI: 0000000000000003 RBP: 00007f8ee5ee0cb4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8ee64beb2f R14: 00007f8ee33fd300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 0f b6 14 11 movzbl (%rcx,%rdx,1),%edx 4: 38 d0 cmp %dl,%al 6: 7c 08 jl 0x10 8: 84 d2 test %dl,%dl a: 0f 85 e1 00 00 00 jne 0xf1 10: 8b 15 38 11 d5 0e mov 0xed51138(%rip),%edx # 0xed5114e 16: 65 01 1d 51 58 b2 7e add %ebx,%gs:0x7eb25851(%rip) # 0x7eb2586e 1d: 85 d2 test %edx,%edx 1f: 75 11 jne 0x32 21: 65 8b 05 46 58 b2 7e mov %gs:0x7eb25846(%rip),%eax # 0x7eb2586e * 28: 0f b6 c0 movzbl %al,%eax <-- trapping instruction 2b: 3d f4 00 00 00 cmp $0xf4,%eax 30: 7f 64 jg 0x96 32: 65 8b 05 35 58 b2 7e mov %gs:0x7eb25835(%rip),%eax # 0x7eb2586e 39: 25 ff ff ff 7f and $0x7fffffff,%eax