INFO: task syz-executor.2:18101 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:syz-executor.2 state:D stack:28272 pid:18101 ppid: 16070 flags:0x00000004 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 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 nbd_add_socket+0x166/0x810 drivers/block/nbd.c:1109 __nbd_ioctl drivers/block/nbd.c:1454 [inline] nbd_ioctl+0x38c/0xb10 drivers/block/nbd.c:1511 blkdev_ioctl+0x37a/0x800 block/ioctl.c:609 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: 0033:0x7f467053fae9 RSP: 002b:00007f466da94188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4670653020 RCX: 00007f467053fae9 RDX: 0000000000000007 RSI: 000000000000ab00 RDI: 0000000000000006 RBP: 00007f4670599f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd55a9a7af R14: 00007f466da94300 R15: 0000000000022000 INFO: task syz-executor.2:18111 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:syz-executor.2 state:D stack:29592 pid:18111 ppid: 16070 flags:0x00000004 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 nbd_ioctl+0x151/0xb10 drivers/block/nbd.c:1504 blkdev_ioctl+0x37a/0x800 block/ioctl.c:609 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: 0033:0x7f467053fae9 RSP: 002b:00007f466da73188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f46706530e0 RCX: 00007f467053fae9 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000006 RBP: 00007f4670599f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd55a9a7af R14: 00007f466da73300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb83b60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6229: #0: ffff88807ee41770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 1 lock held by syz-executor.2/18101: #0: ffff88801a7aa198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x151/0xb10 drivers/block/nbd.c:1504 1 lock held by syz-executor.2/18111: #0: ffff88801a7aa198 (&nbd->config_lock){+.+.}-{3:3}, at: nbd_ioctl+0x151/0xb10 drivers/block/nbd.c:1504 ============================================= 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: 10165 Comm: kworker/u4:8 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:match_held_lock+0x70/0xc0 kernel/locking/lockdep.c:5116 Code: 06 48 0f af c2 0f b7 53 20 81 e2 ff 1f 00 00 48 39 d0 0f 94 c0 48 83 c4 08 0f b6 c0 5b c3 31 f6 e8 c5 fe ff ff 48 85 c0 75 b2 <31> c0 48 83 c4 08 5b c3 48 83 c4 08 b8 01 00 00 00 5b c3 e8 e8 cf RSP: 0018:ffffc9000c057818 EFLAGS: 00000046 RAX: 0000000000000005 RBX: ffff88803a980a88 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8bb83aa0 RDI: ffff88803a980a88 RBP: ffffffff8bb83aa0 R08: 0000000000000000 R09: ffffffff8d917317 R10: fffffbfff1b22e62 R11: 0000000000000000 R12: ffff88803a980000 R13: ffff88803a980a60 R14: 00000000ffffffff R15: ffff88803a980a88 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2391519010 CR3: 000000000b88e000 CR4: 0000000000350ee0 Call Trace: __lock_is_held kernel/locking/lockdep.c:5380 [inline] lock_is_held_type+0xa7/0x140 kernel/locking/lockdep.c:5680 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5648 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x16/0x70 kernel/locking/spinlock.c:194 debug_object_activate+0x287/0x3e0 lib/debugobjects.c:689 debug_timer_activate kernel/time/timer.c:729 [inline] __mod_timer+0x77d/0xe30 kernel/time/timer.c:1050 schedule_timeout+0x145/0x2a0 kernel/time/timer.c:1880 toggle_allocation_gate mm/kfence/core.c:739 [inline] toggle_allocation_gate+0x305/0x390 mm/kfence/core.c:724 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 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 48 0f af c2 imul %rdx,%rax 4: 0f b7 53 20 movzwl 0x20(%rbx),%edx 8: 81 e2 ff 1f 00 00 and $0x1fff,%edx e: 48 39 d0 cmp %rdx,%rax 11: 0f 94 c0 sete %al 14: 48 83 c4 08 add $0x8,%rsp 18: 0f b6 c0 movzbl %al,%eax 1b: 5b pop %rbx 1c: c3 retq 1d: 31 f6 xor %esi,%esi 1f: e8 c5 fe ff ff callq 0xfffffee9 24: 48 85 c0 test %rax,%rax 27: 75 b2 jne 0xffffffdb * 29: 31 c0 xor %eax,%eax <-- trapping instruction 2b: 48 83 c4 08 add $0x8,%rsp 2f: 5b pop %rbx 30: c3 retq 31: 48 83 c4 08 add $0x8,%rsp 35: b8 01 00 00 00 mov $0x1,%eax 3a: 5b pop %rbx 3b: c3 retq 3c: e8 .byte 0xe8 3d: e8 .byte 0xe8 3e: cf iret