INFO: task kworker/u4:16:26505 blocked for more than 143 seconds. Not tainted 5.15.0-next-20211109-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:16 state:D stack:27592 pid:26505 ppid: 2 flags:0x00004000 Workqueue: events_unbound io_ring_exit_work Call Trace: context_switch kernel/sched/core.c:4984 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6265 schedule+0xd2/0x260 kernel/sched/core.c:6338 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6397 __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:9613 [inline] io_uring_try_cancel_requests+0x124/0x6f9 fs/io_uring.c:9643 io_ring_exit_work+0xff/0xbe8 fs/io_uring.c:9441 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 INFO: task syz-executor.4:26693 can't die for more than 143 seconds. task:syz-executor.4 state:R running task stack:28024 pid:26693 ppid: 6576 flags:0x00004006 Call Trace: Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6234: 3 locks held by kworker/u4:16/26505: #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: ffffc9000341fdb0 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273 #2: ffff888035d740a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_uring_try_cancel_iowq fs/io_uring.c:9613 [inline] #2: ffff888035d740a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_uring_try_cancel_requests+0x124/0x6f9 fs/io_uring.c:9643 1 lock held by syz-executor.4/26693: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-next-20211109-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:254 [inline] watchdog+0xcb7/0xed0 kernel/hung_task.c:339 kthread+0x405/0x4f0 kernel/kthread.c:327 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: 26693 Comm: syz-executor.4 Not tainted 5.15.0-next-20211109-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:preempt_count_sub+0x5f/0x150 kernel/sched/core.c:5483 Code: fc 0e 85 c9 75 1b 65 8b 05 be 54 b2 7e 89 c2 81 e2 ff ff ff 7f 39 da 7c 13 81 fb fe 00 00 00 76 63 f7 db 65 01 1d a1 54 b2 7e <5b> c3 e8 3a 4d 84 02 85 c0 74 f5 48 c7 c0 c8 6e 91 8d 48 ba 00 00 RSP: 0018:ffffc90003cd7800 EFLAGS: 00000257 RAX: 0000000000000001 RBX: 00000000ffffffff RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffc90003cd7a10 R08: ffffffff8e106548 R09: 0000000000000001 R10: fffff5200079af28 R11: 000000000008808a R12: ffffc90003cd0000 R13: ffffc90003cd791d R14: ffffc90003cd78e8 R15: ffffffff8e10654c FS: 00007feb742b8700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fac23e3f000 CR3: 000000007b028000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0xee1/0x1ce0 arch/x86/kernel/unwind_orc.c:624 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:6974 [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: 0033:0x7feb76d42ae9 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:00007feb742b8188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: 0000000000001000 RBX: 00007feb76e55f60 RCX: 00007feb76d42ae9 RDX: 0000000000000000 RSI: 000000000000688c RDI: 0000000000000003 RBP: 00007feb76d9cf45 R08: 0000000000000000 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd1ed97d6f R14: 00007feb742b8300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 85 c9 test %ecx,%ecx 2: 75 1b jne 0x1f 4: 65 8b 05 be 54 b2 7e mov %gs:0x7eb254be(%rip),%eax # 0x7eb254c9 b: 89 c2 mov %eax,%edx d: 81 e2 ff ff ff 7f and $0x7fffffff,%edx 13: 39 da cmp %ebx,%edx 15: 7c 13 jl 0x2a 17: 81 fb fe 00 00 00 cmp $0xfe,%ebx 1d: 76 63 jbe 0x82 1f: f7 db neg %ebx 21: 65 01 1d a1 54 b2 7e add %ebx,%gs:0x7eb254a1(%rip) # 0x7eb254c9 * 28: 5b pop %rbx <-- trapping instruction 29: c3 retq 2a: e8 3a 4d 84 02 callq 0x2844d69 2f: 85 c0 test %eax,%eax 31: 74 f5 je 0x28 33: 48 c7 c0 c8 6e 91 8d mov $0xffffffff8d916ec8,%rax 3a: 48 rex.W 3b: ba .byte 0xba