IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready xt_TCPMSS: Only works on TCP SYN packets xt_TCPMSS: Only works on TCP SYN packets xt_TCPMSS: Only works on TCP SYN packets xt_TCPMSS: Only works on TCP SYN packets BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 142s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=8/256 refcnt=9 pending: defense_work_handler, macvlan_process_broadcast, vmstat_shepherd, macvlan_process_broadcast, defense_work_handler, defense_work_handler, cache_reap, check_corruption ====================================================== WARNING: possible circular locking dependency detected 4.19.95-syzkaller #0 Not tainted ------------------------------------------------------ kworker/0:1/17146 is trying to acquire lock: 00000000f6304c61 (console_owner){-.-.}, at: log_next kernel/printk/printk.c:499 [inline] 00000000f6304c61 (console_owner){-.-.}, at: console_unlock+0x432/0x10d0 kernel/printk/printk.c:2416 but task is already holding lock: 0000000077d8ab1f (&(&pool->lock)->rlock){-.-.}, at: show_workqueue_state.cold+0x879/0x1213 kernel/workqueue.c:4582 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&(&pool->lock)->rlock){-.-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] __queue_work+0x23d/0x10a0 kernel/workqueue.c:1417 queue_work_on+0x192/0x200 kernel/workqueue.c:1486 queue_work include/linux/workqueue.h:512 [inline] schedule_work include/linux/workqueue.h:570 [inline] put_pwq kernel/workqueue.c:1090 [inline] put_pwq+0x171/0x1c0 kernel/workqueue.c:1075 put_pwq_unlocked.part.0+0x34/0x70 kernel/workqueue.c:1107 put_pwq_unlocked kernel/workqueue.c:1101 [inline] destroy_workqueue+0x611/0x700 kernel/workqueue.c:4241 do_floppy_init drivers/block/floppy.c:4734 [inline] floppy_async_init+0x2026/0x2165 drivers/block/floppy.c:4751 async_run_entry_fn+0x124/0x570 kernel/async.c:127 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #3 (&pool->lock/1){..-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] __queue_work+0x23d/0x10a0 kernel/workqueue.c:1417 queue_work_on+0x192/0x200 kernel/workqueue.c:1486 queue_work include/linux/workqueue.h:512 [inline] tty_schedule_flip drivers/tty/tty_buffer.c:408 [inline] tty_flip_buffer_push+0xc5/0x100 drivers/tty/tty_buffer.c:551 pty_write+0x1a6/0x200 drivers/tty/pty.c:125 n_tty_write+0xafa/0x1140 drivers/tty/n_tty.c:2354 do_tty_write drivers/tty/tty_io.c:960 [inline] tty_write+0x458/0x7a0 drivers/tty/tty_io.c:1044 __vfs_write+0x114/0x810 fs/read_write.c:485 vfs_write+0x20c/0x560 fs/read_write.c:549 ksys_write+0x14f/0x2d0 fs/read_write.c:599 __do_sys_write fs/read_write.c:611 [inline] __se_sys_write fs/read_write.c:608 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:608 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&(&port->lock)->rlock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 tty_port_tty_get+0x22/0x90 drivers/tty/tty_port.c:288 tty_port_default_wakeup+0x16/0x40 drivers/tty/tty_port.c:47 tty_port_tty_wakeup+0x57/0x70 drivers/tty/tty_port.c:390 uart_write_wakeup+0x46/0x70 drivers/tty/serial/serial_core.c:103 serial8250_tx_chars+0x495/0xaf0 drivers/tty/serial/8250/8250_port.c:1806 serial8250_handle_irq.part.0+0x261/0x2b0 drivers/tty/serial/8250/8250_port.c:1879 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1865 [inline] serial8250_default_handle_irq+0xc0/0x150 drivers/tty/serial/8250/8250_port.c:1895 serial8250_interrupt+0xfc/0x1e0 drivers/tty/serial/8250/8250_core.c:125 __handle_irq_event_percpu+0x144/0x8f0 kernel/irq/handle.c:149 handle_irq_event_percpu+0x74/0x160 kernel/irq/handle.c:189 handle_irq_event+0xa7/0x134 kernel/irq/handle.c:206 handle_edge_irq+0x25e/0x8d0 kernel/irq/chip.c:797 generic_handle_irq_desc include/linux/irqdesc.h:155 [inline] handle_irq+0x39/0x50 arch/x86/kernel/irq_64.c:87 do_IRQ+0x99/0x1d0 arch/x86/kernel/irq.c:246 ret_from_intr+0x0/0x1e native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:556 default_idle_call+0x36/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x30c/0x4d0 kernel/sched/idle.c:263 cpu_startup_entry+0xc8/0xe0 kernel/sched/idle.c:369 start_secondary+0x3e8/0x5b0 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #1 (&port_lock_key){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152 serial8250_console_write+0x7ca/0x9f0 drivers/tty/serial/8250/8250_port.c:3247 univ8250_console_write+0x5f/0x70 drivers/tty/serial/8250/8250_core.c:590 call_console_drivers kernel/printk/printk.c:1736 [inline] console_unlock+0xbdf/0x10d0 kernel/printk/printk.c:2429 vprintk_emit+0x280/0x6d0 kernel/printk/printk.c:1937 vprintk_default+0x28/0x30 kernel/printk/printk.c:1979 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 register_console+0x77f/0xb90 kernel/printk/printk.c:2745 univ8250_console_init+0x3e/0x4b drivers/tty/serial/8250/8250_core.c:685 console_init+0x4f7/0x761 kernel/printk/printk.c:2831 start_kernel+0x59c/0x8c5 init/main.c:660 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:471 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #0 (console_owner){-.-.}: lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3903 console_lock_spinning_enable kernel/printk/printk.c:1599 [inline] console_unlock+0x49c/0x10d0 kernel/printk/printk.c:2426 vprintk_emit+0x280/0x6d0 kernel/printk/printk.c:1937 vprintk_default+0x28/0x30 kernel/printk/printk.c:1979 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 show_pwq kernel/workqueue.c:4488 [inline] show_workqueue_state.cold+0xa05/0x1213 kernel/workqueue.c:4584 wq_watchdog_timer_fn+0x516/0x5a0 kernel/workqueue.c:5596 call_timer_fn+0x18d/0x720 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers kernel/time/timer.c:1684 [inline] __run_timers kernel/time/timer.c:1652 [inline] run_timer_softirq+0xd00/0x16a0 kernel/time/timer.c:1699 __do_softirq+0x25c/0x921 kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1091 do_softirq.part.0+0x11a/0x170 kernel/softirq.c:336 do_softirq kernel/softirq.c:328 [inline] __local_bh_enable_ip+0x211/0x270 kernel/softirq.c:189 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x31/0x40 kernel/locking/spinlock.c:200 spin_unlock_bh include/linux/spinlock.h:374 [inline] htable_selective_cleanup+0x219/0x330 net/netfilter/xt_hashlimit.c:381 htable_gc+0x26/0xc0 net/netfilter/xt_hashlimit.c:392 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 other info that might help us debug this: Chain exists of: console_owner --> &pool->lock/1 --> &(&pool->lock)->rlock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&pool->lock)->rlock); lock(&pool->lock/1); lock(&(&pool->lock)->rlock); lock(console_owner); *** DEADLOCK *** 6 locks held by kworker/0:1/17146: #0: 00000000cce31968 ((wq_completion)"events_power_efficient"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline] #0: 00000000cce31968 ((wq_completion)"events_power_efficient"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000cce31968 ((wq_completion)"events_power_efficient"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000cce31968 ((wq_completion)"events_power_efficient"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000cce31968 ((wq_completion)"events_power_efficient"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000cce31968 ((wq_completion)"events_power_efficient"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000cce31968 ((wq_completion)"events_power_efficient"){+.+.}, at: process_one_work+0x87e/0x1750 kernel/workqueue.c:2124 #1: 000000009dffb3a2 ((work_completion)(&(&hinfo->gc_work)->work)){+.+.}, at: process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128 #2: 000000003a0a9833 ((&wq_watchdog_timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:168 [inline] #2: 000000003a0a9833 ((&wq_watchdog_timer)){+.-.}, at: call_timer_fn+0xda/0x720 kernel/time/timer.c:1316 #3: 0000000053604de0 (rcu_read_lock_sched){....}, at: show_workqueue_state+0x0/0x120 kernel/workqueue.c:4453 #4: 0000000077d8ab1f (&(&pool->lock)->rlock){-.-.}, at: show_workqueue_state.cold+0x879/0x1213 kernel/workqueue.c:4582 #5: 000000006130a060 (console_lock){+.+.}, at: console_trylock_spinning kernel/printk/printk.c:1661 [inline] #5: 000000006130a060 (console_lock){+.+.}, at: vprintk_emit+0x267/0x6d0 kernel/printk/printk.c:1936 stack backtrace: CPU: 0 PID: 17146 Comm: kworker/0:1 Not tainted 4.19.95-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_power_efficient htable_gc Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_circular_bug.isra.0.cold+0x1cc/0x28f kernel/locking/lockdep.c:1221 check_prev_add kernel/locking/lockdep.c:1861 [inline] check_prevs_add kernel/locking/lockdep.c:1974 [inline] validate_chain kernel/locking/lockdep.c:2415 [inline] __lock_acquire+0x2e19/0x49c0 kernel/locking/lockdep.c:3411 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3903 console_lock_spinning_enable kernel/printk/printk.c:1599 [inline] console_unlock+0x49c/0x10d0 kernel/printk/printk.c:2426 vprintk_emit+0x280/0x6d0 kernel/printk/printk.c:1937 vprintk_default+0x28/0x30 kernel/printk/printk.c:1979 vprintk_func+0x7e/0x189 kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 show_pwq kernel/workqueue.c:4488 [inline] show_workqueue_state.cold+0xa05/0x1213 kernel/workqueue.c:4584 wq_watchdog_timer_fn+0x516/0x5a0 kernel/workqueue.c:5596 call_timer_fn+0x18d/0x720 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers kernel/time/timer.c:1684 [inline] __run_timers kernel/time/timer.c:1652 [inline] run_timer_softirq+0xd00/0x16a0 kernel/time/timer.c:1699 __do_softirq+0x25c/0x921 kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1091 do_softirq.part.0+0x11a/0x170 kernel/softirq.c:336 do_softirq kernel/softirq.c:328 [inline] __local_bh_enable_ip+0x211/0x270 kernel/softirq.c:189 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x31/0x40 kernel/locking/spinlock.c:200 spin_unlock_bh include/linux/spinlock.h:374 [inline] htable_selective_cleanup+0x219/0x330 net/netfilter/xt_hashlimit.c:381 htable_gc+0x26/0xc0 net/netfilter/xt_hashlimit.c:392 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 workqueue events_long: flags=0x0 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: br_fdb_cleanup workqueue events_power_efficient: flags=0x80 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=4/256 refcnt=6 in-flight: 17146:htable_gc BAR(17170) pending: htable_gc, device_uncache_fw_images_work, neigh_periodic_work workqueue mm_percpu_wq: flags=0x8 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256 refcnt=4 pending: vmstat_update, drain_local_pages_wq BAR(1089) workqueue dm_bufio_cache: flags=0x8 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: work_fn workqueue krxrpcd: flags=0x0 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=5 pending: rxrpc_peer_keepalive_worker delayed: rxrpc_peer_keepalive_worker, rxrpc_peer_keepalive_worker, rxrpc_peer_keepalive_worker pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=143s workers=5 idle: 17150 17104 2918 8232 pool 4: cpus=0-1 flags=0x4 nice=0 hung=0s workers=6 idle: 2361 54 12031 17167 7