block nbd0: Device being setup by another task INFO: task kworker/u4:1:23 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:1 D25184 23 2 0x80000000 EXT4-fs (loop5): Unrecognized mount option "0" or missing value Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_timeout+0x92d/0xfe0 kernel/time/timer.c:1794 9pnet: Insufficient options for proto=fd do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common+0x29c/0x470 kernel/sched/completion.c:115 block nbd0: Device being setup by another task flush_workqueue+0x40b/0x13e0 kernel/workqueue.c:2713 flush_scheduled_work include/linux/workqueue.h:599 [inline] tipc_exit_net+0x38/0x60 net/tipc/core.c:100 ops_exit_list+0xa5/0x150 net/core/net_namespace.c:153 cleanup_net+0x3b4/0x8b0 net/core/net_namespace.c:554 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Showing all locks held in the system: 3 locks held by kworker/u4:1/23: #0: 00000000a12543ae ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000d9beca1b (net_cleanup_work){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 00000000de74b402 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa8/0x8b0 net/core/net_namespace.c:521 2 locks held by kworker/u4:4/1389: 1 lock held by khungtaskd/1557: #0: 000000004b5dcd1a (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by systemd-udevd/4701: 1 lock held by in:imklog/7780: #0: 0000000061a70d57 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by kworker/1:1/348: #0: 0000000070178684 ((wq_completion)"events"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 000000002f886f7c ((work_completion)(&m->rq)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 3 locks held by syz-executor.5/20282: #0: 00000000d1f79931 (cpu_hotplug_lock.rw_sem){++++}, at: get_online_cpus include/linux/cpu.h:137 [inline] #0: 00000000d1f79931 (cpu_hotplug_lock.rw_sem){++++}, at: kmem_cache_destroy+0x2f/0x310 mm/slab_common.c:890 #1: 0000000035becdec (mem_hotplug_lock.rw_sem){++++}, at: kmem_cache_destroy+0x34/0x310 mm/slab_common.c:891 #2: 000000007849db64 (slab_mutex){+.+.}, at: kmem_cache_destroy+0x42/0x310 mm/slab_common.c:893 3 locks held by syz-executor.1/20294: 3 locks held by syz-executor.4/20316: #0: 00000000d1f79931 (cpu_hotplug_lock.rw_sem){++++}, at: get_online_cpus include/linux/cpu.h:137 [inline] #0: 00000000d1f79931 (cpu_hotplug_lock.rw_sem){++++}, at: kmem_cache_destroy+0x2f/0x310 mm/slab_common.c:890 #1: 0000000035becdec (mem_hotplug_lock.rw_sem){++++}, at: kmem_cache_destroy+0xdd/0x310 mm/slab_common.c:910 #2: 000000007849db64 (slab_mutex){+.+.}, at: kmem_cache_destroy+0xeb/0x310 mm/slab_common.c:912 1 lock held by syz-executor.0/20335: block nbd0: Device being setup by another task 2 locks held by syz-executor.3/20341: #0: 0000000079616f8d (&rq->lock){-.-.}, at: idle_balance kernel/sched/fair.c:9702 [inline] #0: 0000000079616f8d (&rq->lock){-.-.}, at: pick_next_task_fair+0x556/0x1570 kernel/sched/fair.c:6841 #1: 000000004b5dcd1a (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] #1: 000000004b5dcd1a (rcu_read_lock){....}, at: update_curr+0x2c3/0x870 kernel/sched/fair.c:857 1 lock held by syz-executor.2/20338: #0: 000000002cede837 (loop_ctl_mutex){+.+.}, at: loop_set_fd drivers/block/loop.c:956 [inline] #0: 000000002cede837 (loop_ctl_mutex){+.+.}, at: lo_ioctl+0x1bb/0x20e0 drivers/block/loop.c:1576 2 locks held by systemd-udevd/20339: EXT4-fs (loop2): Unrecognized mount option "0" or missing value ============================================= EXT4-fs (loop3): Unrecognized mount option "0" or missing value NMI backtrace for cpu 1 CPU: 1 PID: 1557 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8157 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 RIP: 0010:__read_once_size include/linux/compiler.h:263 [inline] RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:2317 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:2337 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:2391 [inline] RIP: 0010:__lock_acquire+0xbfd/0x3ff0 kernel/locking/lockdep.c:3416 Code: fc ff df eb 06 48 83 eb 08 74 3d 48 8d 7b 18 48 89 f8 48 c1 e8 03 80 3c 28 00 0f 85 8c 1e 00 00 4c 3b 63 18 0f 84 f1 fc ff ff <48> 8d 7b 08 48 89 f8 48 c1 e8 03 80 3c 28 00 0f 85 93 1e 00 00 48 RSP: 0018:ffff8880a03af8e0 EFLAGS: 00000003 RAX: 1ffffffff18eebab RBX: ffffffff8c775d40 RCX: 0000000000003253 RDX: 1ffffffff19a60fb RSI: 000000005bd9f4b5 RDI: ffffffff8c775d58 RBP: dffffc0000000000 R08: ffffffff8cd307d8 R09: 0000000000000000 R10: ffff88809f43eb48 R11: 0000000000000001 R12: 1a707d6f3ca8be5e R13: ffff88809f43e2c0 R14: ffff88809f43eb60 R15: 0000000000000001 FS: 0000555556f95400(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff65fe5d18 CR3: 00000000af8ff000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 00000000b8fecd19 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 finish_lock_switch kernel/sched/core.c:2577 [inline] finish_task_switch+0x13e/0x760 kernel/sched/core.c:2678 context_switch kernel/sched/core.c:2831 [inline] __schedule+0x88f/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 freezable_schedule include/linux/freezer.h:172 [inline] do_nanosleep+0x264/0x6c0 kernel/time/hrtimer.c:1755 hrtimer_nanosleep+0x24d/0x570 kernel/time/hrtimer.c:1809 common_nsleep+0x23/0x30 kernel/time/posix-timers.c:1204 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1231 [inline] __se_sys_clock_nanosleep+0x261/0x360 kernel/time/posix-timers.c:1209 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fb410752e21 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 aa e7 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 e3 e7 ff ff 48 8b 04 24 eb 97 66 2e 0f 1f RSP: 002b:00007fffdcef4e50 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000000000000fb6 RCX: 00007fb410752e21 RDX: 00007fffdcef4e90 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fffdcef4f1c R08: 0000000000000000 R09: 0000010af301e266 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 R13: 00000000000fd802 R14: 0000000000000007 R15: 00007fffdcef4f80