BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 265s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=17/256 refcnt=18 in-flight: 7993:rtc_timer_do_work pending: defense_work_handler, destroy_super_work, defense_work_handler, defense_work_handler, cache_reap, macvlan_process_broadcast, macvlan_process_broadcast, hci_cmd_timeout, hci_cmd_timeout, hci_cmd_timeout, hci_cmd_timeout, hci_cmd_timeout, hci_cmd_timeout, macvlan_process_broadcast, macvlan_process_broadcast, switchdev_deferred_process_work pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: defense_work_handler workqueue events_long: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=4/256 refcnt=5 pending: gc_worker, br_fdb_cleanup, br_fdb_cleanup, br_fdb_cleanup workqueue events_unbound: flags=0x2 pwq 4: cpus=0-1 flags=0x4 nice=0 active=4/512 refcnt=7 in-flight: 5:fsnotify_mark_destroy_workfn fsnotify_mark_destroy_workfn, 9298:fsnotify_connector_destroy_workfn fsnotify_connector_destroy_workfn workqueue events_freezable: flags=0x4 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: update_balloon_stats_func workqueue events_power_efficient: flags=0x80 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=3/256 refcnt=4 pending: process_srcu, neigh_periodic_work, check_lifetime workqueue mm_percpu_wq: flags=0x8 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 refcnt=4 pending: vmstat_update, lru_add_drain_per_cpu BAR(10388) workqueue dm_bufio_cache: flags=0x8 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: work_fn workqueue ipv6_addrconf: flags=0x40008 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 refcnt=2 pending: addrconf_verify_work workqueue bat_events: flags=0xe000a pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=13 pending: batadv_iv_send_outstanding_bat_ogm_packet delayed: batadv_iv_send_outstanding_bat_ogm_packet, batadv_nc_worker, batadv_nc_worker, batadv_nc_worker, batadv_nc_worker, batadv_nc_worker, batadv_nc_worker, batadv_mcast_mla_update, batadv_mcast_mla_update pool 2: cpus=1 node=0 flags=0x0 nice=0 hung=265s workers=3 idle: 9115 4316 pool 4: cpus=0-1 flags=0x4 nice=0 hung=0s workers=4 idle: 201 3529 INFO: task kworker/u4:0:5 blocked for more than 140 seconds. Not tainted 4.14.286-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:0 D27112 5 2 0x80000000 Workqueue: events_unbound fsnotify_mark_destroy_workfn Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1724 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common+0x272/0x430 kernel/sched/completion.c:123 __synchronize_srcu+0x10a/0x1d0 kernel/rcu/srcutree.c:898 fsnotify_mark_destroy_workfn+0xed/0x2e0 fs/notify/mark.c:757 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task kworker/u4:6:9298 blocked for more than 140 seconds. Not tainted 4.14.286-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:6 D28880 9298 2 0x80000000 Workqueue: events_unbound fsnotify_connector_destroy_workfn Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1724 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common+0x272/0x430 kernel/sched/completion.c:123 __synchronize_srcu+0x10a/0x1d0 kernel/rcu/srcutree.c:898 fsnotify_connector_destroy_workfn+0x49/0xa0 fs/notify/mark.c:156 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: task systemd-udevd:10359 blocked for more than 140 seconds. Not tainted 4.14.286-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. systemd-udevd D28640 10359 4628 0x00000304 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 blk_queue_enter+0x3e2/0x4b0 block/blk-core.c:800 generic_make_request block/blk-core.c:2223 [inline] generic_make_request+0x19d/0x850 block/blk-core.c:2173 submit_bio+0x234/0x390 block/blk-core.c:2303 mpage_bio_submit fs/mpage.c:66 [inline] mpage_readpages+0x431/0x5f0 fs/mpage.c:393 read_pages mm/readahead.c:121 [inline] __do_page_cache_readahead+0x522/0x940 mm/readahead.c:199 force_page_cache_readahead+0x1ef/0x310 mm/readahead.c:232 page_cache_sync_readahead mm/readahead.c:513 [inline] page_cache_sync_readahead+0xca/0xf0 mm/readahead.c:503 generic_file_buffered_read mm/filemap.c:2003 [inline] generic_file_read_iter+0xfbc/0x21c0 mm/filemap.c:2273 blkdev_read_iter+0x111/0x1b0 fs/block_dev.c:1958 call_read_iter include/linux/fs.h:1774 [inline] new_sync_read fs/read_write.c:401 [inline] __vfs_read+0x449/0x620 fs/read_write.c:413 vfs_read+0x139/0x340 fs/read_write.c:447 SYSC_read fs/read_write.c:574 [inline] SyS_read+0xf2/0x210 fs/read_write.c:567 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f1b73d52210 RSP: 002b:00007ffc6e496c48 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055dcdcdcba20 RCX: 00007f1b73d52210 RDX: 0000000000000561 RSI: 000055dcdcdcba48 RDI: 000000000000000f RBP: 000055dcdcdce880 R08: 00007f1b73d3cfb8 R09: 00000000000005a0 R10: 000055dcdcdcba38 R11: 0000000000000246 R12: 0000000000002000 R13: 0000000000002561 R14: 000055dcdcdce8d0 R15: 0000000000000561 INFO: task syz-executor.3:10388 blocked for more than 140 seconds. Not tainted 4.14.286-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28552 10388 7970 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1724 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common+0x272/0x430 kernel/sched/completion.c:123 flush_work+0x3fe/0x770 kernel/workqueue.c:2894 lru_add_drain_all_cpuslocked+0x2e6/0x450 mm/swap.c:722 lru_add_drain_all+0xf/0x20 mm/swap.c:730 invalidate_bdev+0x8a/0xc0 fs/block_dev.c:109 loop_clr_fd+0x4c8/0xc20 drivers/block/loop.c:1062 lo_ioctl+0x895/0x1cd0 drivers/block/loop.c:1424 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x540/0x1830 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1893 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f47ee13aec7 RSP: 002b:00007f47ecaaff88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f47ee13aec7 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004 RBP: 00007f47ecab06b8 R08: 00007f47ecab0020 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000016 R14: 00007f47ecaaffe0 R15: 0000000020000040 INFO: task syz-executor.1:10409 blocked for more than 140 seconds. Not tainted 4.14.286-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D30648 10409 7971 0x00000004 Call Trace: context_switch kernel/sched/core.c:2811 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3387 schedule+0x8d/0x1b0 kernel/sched/core.c:3431 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3489 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x669/0x1310 kernel/locking/mutex.c:893 lru_add_drain_all_cpuslocked+0x6c/0x450 mm/swap.c:704 lru_add_drain_all+0xf/0x20 mm/swap.c:730 do_mlock+0x90/0x5e0 mm/mlock.c:673 SYSC_mlock2 mm/mlock.c:726 [inline] SyS_mlock2+0x49/0x70 mm/mlock.c:716 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f5e13c9b109 RSP: 002b:00007f5e125ad168 EFLAGS: 00000246 ORIG_RAX: 0000000000000145 RAX: ffffffffffffffda RBX: 00007f5e13dae1d0 RCX: 00007f5e13c9b109 RDX: 0000000000000000 RSI: 0000000000001000 RDI: 00000000203b6000 RBP: 00007f5e13cf505d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff69301a9f R14: 00007f5e125ad300 R15: 0000000000022000 Showing all locks held in the system: 2 locks held by kworker/u4:0/5: #0: ("events_unbound"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: ((reaper_work).work){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 1 lock held by khungtaskd/1534: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by kworker/u4:6/9298: #0: ("events_unbound"){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2088 #1: (connector_reaper_work){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2092 3 locks held by syz-executor.3/10388: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1cd0 drivers/block/loop.c:1414 #1: (cpu_hotplug_lock.rw_sem){++++}, at: [] get_online_cpus include/linux/cpu.h:149 [inline] #1: (cpu_hotplug_lock.rw_sem){++++}, at: [] lru_add_drain_all+0xa/0x20 mm/swap.c:729 #2: (lock#6){+.+.}, at: [] lru_add_drain_all_cpuslocked+0x6c/0x450 mm/swap.c:704 2 locks held by syz-executor.1/10409: #0: (cpu_hotplug_lock.rw_sem){++++}, at: [] get_online_cpus include/linux/cpu.h:149 [inline] #0: (cpu_hotplug_lock.rw_sem){++++}, at: [] lru_add_drain_all+0xa/0x20 mm/swap.c:729 #1: (lock#6){+.+.}, at: [] lru_add_drain_all_cpuslocked+0x6c/0x450 mm/swap.c:704 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1534 Comm: khungtaskd Not tainted 4.14.286-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 7993 Comm: kworker/1:3 Not tainted 4.14.286-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Workqueue: events rtc_timer_do_work task: ffff88809178a140 task.stack: ffff8880a0cd8000 RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:774 [inline] RIP: 0010:trace_hardirqs_on_caller+0x13b/0x580 kernel/locking/lockdep.c:2913 RSP: 0000:ffff8880a0cdfaa8 EFLAGS: 00000086 RAX: 1ffffffff11e1340 RBX: ffffffff8beccd80 RCX: 1ffffffff127a594 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffff88809178a990 RBP: ffffffff8723f069 R08: ffff8882378645e0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff1101419bf5e FS: 0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc9139f8cbb CR3: 00000000af047000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: Code: 00 9a f0 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 0c 04 00 00 48 83 3d 4c 21 af 07 00 0f 84 4e 03 00 00 9c <58> 0f 1f 44 00 00 f6 c4 02 0f 85 8e 03 00 00 48 b8 00 00 00 00 ---------------- Code disassembly (best guess), 4 bytes skipped: 0: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 7: fc ff df a: 48 c1 e8 03 shr $0x3,%rax e: 80 3c 10 00 cmpb $0x0,(%rax,%rdx,1) 12: 0f 85 0c 04 00 00 jne 0x424 18: 48 83 3d 4c 21 af 07 cmpq $0x0,0x7af214c(%rip) # 0x7af216c 1f: 00 20: 0f 84 4e 03 00 00 je 0x374 26: 9c pushfq * 27: 58 pop %rax <-- trapping instruction 28: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 2d: f6 c4 02 test $0x2,%ah 30: 0f 85 8e 03 00 00 jne 0x3c4 36: 48 rex.W 37: b8 00 00 00 00 mov $0x0,%eax