audit: type=1400 audit(1583074963.576:36): avc: denied { map } for pid=7392 comm="syz-executor572" path="/root/syz-executor572389225" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 146s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 refcnt=3 in-flight: 2759:rtc_timer_do_work pending: cache_reap ====================================================== WARNING: possible circular locking dependency detected 4.14.172-syzkaller #0 Not tainted ------------------------------------------------------ swapper/0/0 is trying to acquire lock: (console_owner){-.-.}, at: [] log_next kernel/printk/printk.c:493 [inline] (console_owner){-.-.}, at: [] console_unlock+0x36c/0xec0 kernel/printk/printk.c:2384 but task is already holding lock: (&(&pool->lock)->rlock){-.-.}, at: [] show_workqueue_state.cold+0x706/0xedd kernel/workqueue.c:4517 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+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] __queue_work+0x1ba/0xf10 kernel/workqueue.c:1419 queue_work_on+0x159/0x1d0 kernel/workqueue.c:1488 queue_work include/linux/workqueue.h:491 [inline] schedule_work include/linux/workqueue.h:549 [inline] put_pwq kernel/workqueue.c:1092 [inline] put_pwq+0x129/0x180 kernel/workqueue.c:1077 put_pwq_unlocked.part.0+0x30/0x70 kernel/workqueue.c:1109 put_pwq_unlocked kernel/workqueue.c:1103 [inline] destroy_workqueue+0x570/0x660 kernel/workqueue.c:4171 do_floppy_init drivers/block/floppy.c:4732 [inline] floppy_async_init+0x1abb/0x1c06 drivers/block/floppy.c:4749 async_run_entry_fn+0x102/0x4c0 kernel/async.c:127 process_one_work+0x813/0x1540 kernel/workqueue.c:2114 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2248 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #3 (&pool->lock/1){..-.}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] __queue_work+0x1ba/0xf10 kernel/workqueue.c:1419 queue_work_on+0x159/0x1d0 kernel/workqueue.c:1488 pty_write+0x173/0x1c0 drivers/tty/pty.c:125 n_tty_write+0x8dd/0xe30 drivers/tty/n_tty.c:2356 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x3f0/0x700 drivers/tty/tty_io.c:1043 __vfs_write+0xe4/0x630 fs/read_write.c:480 vfs_write+0x192/0x4e0 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0xf2/0x210 fs/read_write.c:582 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 -> #2 (&(&port->lock)->rlock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:160 tty_port_tty_get+0x1d/0x80 drivers/tty/tty_port.c:288 tty_port_default_wakeup+0x11/0x40 drivers/tty/tty_port.c:46 serial8250_tx_chars+0x400/0x9e0 drivers/tty/serial/8250/8250_port.c:1810 serial8250_handle_irq.part.0+0x1f8/0x240 drivers/tty/serial/8250/8250_port.c:1883 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1869 [inline] serial8250_default_handle_irq+0x96/0x110 drivers/tty/serial/8250/8250_port.c:1899 serial8250_interrupt+0xe4/0x1a0 drivers/tty/serial/8250/8250_core.c:129 __handle_irq_event_percpu+0x125/0x7e0 kernel/irq/handle.c:147 handle_irq_event_percpu+0x66/0x120 kernel/irq/handle.c:187 handle_irq_event+0xa2/0x12d kernel/irq/handle.c:204 handle_edge_irq+0x215/0x810 kernel/irq/chip.c:770 generic_handle_irq_desc include/linux/irqdesc.h:159 [inline] handle_irq+0x35/0x50 arch/x86/kernel/irq_64.c:87 do_IRQ+0x93/0x1d0 arch/x86/kernel/irq.c:230 ret_from_intr+0x0/0x1e native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x47/0x370 arch/x86/kernel/process.c:566 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x250/0x3c0 kernel/sched/idle.c:246 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:351 start_kernel+0x659/0x676 init/main.c:708 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #1 (&port_lock_key){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xbf kernel/locking/spinlock.c:160 serial8250_console_write+0x6c1/0x8e0 drivers/tty/serial/8250/8250_port.c:3236 call_console_drivers kernel/printk/printk.c:1725 [inline] console_unlock+0x9b2/0xec0 kernel/printk/printk.c:2397 vprintk_emit kernel/printk/printk.c:1923 [inline] vprintk_emit+0x1f8/0x600 kernel/printk/printk.c:1888 vprintk_func+0x58/0x152 kernel/printk/printk_safe.c:401 printk+0x9e/0xbc kernel/printk/printk.c:1996 register_console+0x5ec/0x9a0 kernel/printk/printk.c:2716 univ8250_console_init+0x2f/0x3a drivers/tty/serial/8250/8250_core.c:691 console_init+0x46/0x53 kernel/printk/printk.c:2797 start_kernel+0x437/0x676 init/main.c:634 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #0 (console_owner){-.-.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994 console_lock_spinning_enable kernel/printk/printk.c:1588 [inline] console_unlock+0x3d4/0xec0 kernel/printk/printk.c:2394 vprintk_emit kernel/printk/printk.c:1923 [inline] vprintk_emit+0x1f8/0x600 kernel/printk/printk.c:1888 vprintk_func+0x58/0x152 kernel/printk/printk_safe.c:401 printk+0x9e/0xbc kernel/printk/printk.c:1996 show_pwq kernel/workqueue.c:4423 [inline] show_workqueue_state.cold+0x849/0xedd kernel/workqueue.c:4519 wq_watchdog_timer_fn+0x3d0/0x440 kernel/workqueue.c:5503 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279 expire_timers kernel/time/timer.c:1318 [inline] __run_timers kernel/time/timer.c:1636 [inline] __run_timers kernel/time/timer.c:1604 [inline] run_timer_softirq+0xac2/0x1390 kernel/time/timer.c:1651 __do_softirq+0x254/0x9bf kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15b/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x47/0x370 arch/x86/kernel/process.c:566 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x250/0x3c0 kernel/sched/idle.c:246 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:351 start_kernel+0x659/0x676 init/main.c:708 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 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 *** 4 locks held by swapper/0/0: #0: (kernel/workqueue.c:5441){+.-.}, at: [] lockdep_copy_map include/linux/lockdep.h:174 [inline] #0: (kernel/workqueue.c:5441){+.-.}, at: [] call_timer_fn+0xb8/0x650 kernel/time/timer.c:1269 #1: (rcu_read_lock_sched){....}, at: [] show_workqueue_state+0x0/0xf0 kernel/workqueue.c:4359 #2: (&(&pool->lock)->rlock){-.-.}, at: [] show_workqueue_state.cold+0x706/0xedd kernel/workqueue.c:4517 #3: (console_lock){+.+.}, at: [] console_trylock_spinning kernel/printk/printk.c:1650 [inline] #3: (console_lock){+.+.}, at: [] vprintk_emit kernel/printk/printk.c:1922 [inline] #3: (console_lock){+.+.}, at: [] vprintk_emit+0x1ea/0x600 kernel/printk/printk.c:1888 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.172-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 print_circular_bug.isra.0.cold+0x1c4/0x282 kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1901 [inline] check_prevs_add kernel/locking/lockdep.c:2018 [inline] validate_chain kernel/locking/lockdep.c:2460 [inline] __lock_acquire+0x2cb3/0x4620 kernel/locking/lockdep.c:3487 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3994 console_lock_spinning_enable kernel/printk/printk.c:1588 [inline] console_unlock+0x3d4/0xec0 kernel/printk/printk.c:2394 vprintk_emit kernel/printk/printk.c:1923 [inline] vprintk_emit+0x1f8/0x600 kernel/printk/printk.c:1888 vprintk_func+0x58/0x152 kernel/printk/printk_safe.c:401 printk+0x9e/0xbc kernel/printk/printk.c:1996 show_pwq kernel/workqueue.c:4423 [inline] show_workqueue_state.cold+0x849/0xedd kernel/workqueue.c:4519 wq_watchdog_timer_fn+0x3d0/0x440 kernel/workqueue.c:5503 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1279 expire_timers kernel/time/timer.c:1318 [inline] __run_timers kernel/time/timer.c:1636 [inline] __run_timers kernel/time/timer.c:1604 [inline] run_timer_softirq+0xac2/0x1390 kernel/time/timer.c:1651 __do_softirq+0x254/0x9bf kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x15b/0x1a0 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x141/0x5e0 arch/x86/kernel/apic/apic.c:1102 apic_timer_interrupt+0x8f/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 RSP: 0018:ffffffff87c07e78 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: 1ffffffff0fa2ce4 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff87c76abc RBP: ffffffff87d16710 R08: 1ffffffff1124101 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: fffffbfff0f8ec48 R13: ffffffff87c76240 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x47/0x370 arch/x86/kernel/process.c:566 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x250/0x3c0 kernel/sched/idle.c:246 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:351 start_kernel+0x659/0x676 init/main.c:708 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 workqueue events_power_efficient: flags=0x80 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 refcnt=3 pending: fb_flashcursor, neigh_periodic_work workqueue mm_percpu_wq: flags=0x8 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: vmstat_update workqueue dm_bufio_cache: flags=0x8 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: work_fn pool 2: cpus=1 node=0 flags=0x0 nice=0 hung=147s workers=2 idle: 18