INFO: task syz-executor308:6544 can't die for more than 143 seconds. task:syz-executor308 state:D stack:26784 pid: 6544 ppid: 6543 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4953 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6234 schedule+0xd2/0x260 kernel/sched/core.c:6307 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 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+0x174/0x270 kernel/sched/completion.c:138 flush_workqueue+0x3ed/0x15b0 kernel/workqueue.c:2869 nbd_start_device_ioctl drivers/block/nbd.c:1364 [inline] __nbd_ioctl drivers/block/nbd.c:1427 [inline] nbd_ioctl+0x6d8/0xb10 drivers/block/nbd.c:1467 blkdev_ioctl+0x2a1/0x700 block/ioctl.c:589 block_ioctl+0xfa/0x140 block/fops.c:478 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fd8d39a4389 RSP: 002b:00007ffcce3d0ae8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd8d39a4389 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffcce3d0c88 R09: 00007ffcce3d0c88 R10: 00007ffcce3d0c88 R11: 0000000000000246 R12: 00007fd8d39636a0 R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor308:6544 blocked for more than 143 seconds. Not tainted 5.15.0-rc4-next-20211008-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor308 state:D stack:26784 pid: 6544 ppid: 6543 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4953 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6234 schedule+0xd2/0x260 kernel/sched/core.c:6307 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 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+0x174/0x270 kernel/sched/completion.c:138 flush_workqueue+0x3ed/0x15b0 kernel/workqueue.c:2869 nbd_start_device_ioctl drivers/block/nbd.c:1364 [inline] __nbd_ioctl drivers/block/nbd.c:1427 [inline] nbd_ioctl+0x6d8/0xb10 drivers/block/nbd.c:1467 blkdev_ioctl+0x2a1/0x700 block/ioctl.c:589 block_ioctl+0xfa/0x140 block/fops.c:478 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fd8d39a4389 RSP: 002b:00007ffcce3d0ae8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd8d39a4389 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffcce3d0c88 R09: 00007ffcce3d0c88 R10: 00007ffcce3d0c88 R11: 0000000000000246 R12: 00007fd8d39636a0 R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb813a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 3 locks held by kworker/u4:2/44: #0: ffff8880b9c39a58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x1e/0x30 kernel/sched/core.c:478 #1: ffff8880b9c279c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x173/0x490 kernel/sched/psi.c:871 #2: ffff8880b9c28258 (&base->lock){..-.}-{2:2}, at: lock_timer_base+0x5a/0x1f0 kernel/time/timer.c:946 3 locks held by kworker/u5:0/46: #0: ffff88807be8b138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88807be8b138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88807be8b138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff88807be8b138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline] #0: ffff88807be8b138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline] #0: ffff88807be8b138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2268 #1: ffffc9000116fdb0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272 #2: ffff88801c1a4120 (sk_lock-AF_AX25){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1637 [inline] #2: ffff88801c1a4120 (sk_lock-AF_AX25){+.+.}-{0:0}, at: ax25_recvmsg+0xbc/0x850 net/ax25/af_ax25.c:1627 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc4-next-20211008-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: 44 Comm: kworker/u4:2 Not tainted 5.15.0-rc4-next-20211008-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:590 [inline] RIP: 0010:queued_spin_unlock arch/x86/include/asm/qspinlock.h:56 [inline] RIP: 0010:do_raw_spin_unlock+0x147/0x230 kernel/locking/spinlock_debug.c:141 Code: c1 ea 03 0f b6 14 02 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 92 00 00 00 48 c7 c0 20 6e 9f 8b c7 45 08 ff ff ff ff <48> ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 b7 00 RSP: 0018:ffffc9000114f9d0 EFLAGS: 00000246 RAX: ffffffff8b9f6e20 RBX: 0000000000000007 RCX: ffffffff815c2670 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888010db8120 RBP: ffff888010db8120 R08: 0000000000000000 R09: ffff888010db8123 R10: ffffed10021b7024 R11: 000000000000003f R12: ffff888010db8128 R13: ffff888010db8130 R14: 0000000000000f8a R15: ffffffff8bcac5c0 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7372c12020 CR3: 000000000b88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock include/linux/spinlock_api_smp.h:151 [inline] _raw_spin_unlock+0x1a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:408 [inline] __text_poke+0x5d4/0x8c0 arch/x86/kernel/alternative.c:876 text_poke_bp_batch+0x3d7/0x560 arch/x86/kernel/alternative.c:1178 text_poke_flush arch/x86/kernel/alternative.c:1268 [inline] text_poke_flush arch/x86/kernel/alternative.c:1265 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1275 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d5/0x430 kernel/jump_label.c:830 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177 static_key_enable+0x16/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:731 [inline] toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:723 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.161 msecs ---------------- Code disassembly (best guess): 0: c1 ea 03 shr $0x3,%edx 3: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx 7: 4c 89 e0 mov %r12,%rax a: 83 e0 07 and $0x7,%eax d: 83 c0 03 add $0x3,%eax 10: 38 d0 cmp %dl,%al 12: 7c 08 jl 0x1c 14: 84 d2 test %dl,%dl 16: 0f 85 92 00 00 00 jne 0xae 1c: 48 c7 c0 20 6e 9f 8b mov $0xffffffff8b9f6e20,%rax 23: c7 45 08 ff ff ff ff movl $0xffffffff,0x8(%rbp) * 2a: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx <-- trapping instruction 31: fc ff df 34: 48 c1 e8 03 shr $0x3,%rax 38: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) 3c: 0f .byte 0xf 3d: 85 .byte 0x85 3e: b7 00 mov $0x0,%bh