audit: type=1800 audit(1592388337.164:90): pid=31524 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="syz-executor.5" name="file0" dev="sda1" ino=16119 res=0 ====================================================== WARNING: possible circular locking dependency detected 4.14.184-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/31539 is trying to acquire lock: (&pool->lock/1){..-.}, at: [] spin_lock include/linux/spinlock.h:317 [inline] (&pool->lock/1){..-.}, at: [] __queue_work+0x174/0xf70 kernel/workqueue.c:1421 but task is already holding lock: (&(&port->lock)->rlock){-.-.}, at: [] pty_write+0xdb/0x1c0 drivers/tty/pty.c:120 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&(&port->lock)->rlock){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 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+0x400/0x9f0 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+0xee/0x7f0 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+0x751/0x771 init/main.c:708 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #3 (&port_lock_key){-.-.}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160 serial8250_console_write+0x6ea/0x8e0 drivers/tty/serial/8250/8250_port.c:3236 call_console_drivers kernel/printk/printk.c:1725 [inline] console_unlock+0x985/0xee0 kernel/printk/printk.c:2397 vprintk_emit+0x3b8/0x600 kernel/printk/printk.c:1923 vprintk_func+0x58/0x152 kernel/printk/printk_safe.c:401 printk+0x9e/0xbc kernel/printk/printk.c:1996 register_console+0x6ef/0xac0 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+0x52f/0x771 init/main.c:634 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:240 -> #2 (console_owner){-.-.}: console_lock_spinning_enable kernel/printk/printk.c:1588 [inline] console_unlock+0x36c/0xee0 kernel/printk/printk.c:2394 vprintk_emit+0x3b8/0x600 kernel/printk/printk.c:1923 vprintk_func+0x58/0x152 kernel/printk/printk_safe.c:401 printk+0x9e/0xbc kernel/printk/printk.c:1996 fail_dump lib/fault-inject.c:44 [inline] should_fail.cold+0xdf/0x154 lib/fault-inject.c:149 should_failslab+0xd6/0x130 mm/failslab.c:32 slab_pre_alloc_hook mm/slab.h:421 [inline] slab_alloc mm/slab.c:3376 [inline] kmem_cache_alloc+0x40/0x3c0 mm/slab.c:3550 kmem_cache_zalloc include/linux/slab.h:651 [inline] fill_pool lib/debugobjects.c:110 [inline] __debug_object_init+0x57d/0x7a0 lib/debugobjects.c:341 __init_work kernel/workqueue.c:504 [inline] insert_wq_barrier kernel/workqueue.c:2500 [inline] start_flush_work kernel/workqueue.c:2848 [inline] flush_work+0x1f7/0x780 kernel/workqueue.c:2892 snd_seq_client_use_ptr+0x2aa/0x330 sound/core/seq/seq_clientmgr.c:164 snd_seq_info_clients_read+0x146/0x705 sound/core/seq/seq_clientmgr.c:2466 snd_info_seq_show+0xc5/0x110 sound/core/info.c:378 seq_read+0x4d2/0x1130 fs/seq_file.c:237 proc_reg_read+0xf2/0x160 fs/proc/inode.c:217 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3e3/0x5a0 fs/read_write.c:919 vfs_readv+0xd3/0x130 fs/read_write.c:981 do_preadv+0x161/0x200 fs/read_write.c:1065 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb -> #1 (&(&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+0x174/0xf70 kernel/workqueue.c:1421 queue_work_on+0x159/0x1d0 kernel/workqueue.c:1490 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:4173 do_floppy_init drivers/block/floppy.c:4732 [inline] floppy_async_init+0x1ba8/0x1cf3 drivers/block/floppy.c:4749 async_run_entry_fn+0x102/0x4c0 kernel/async.c:127 process_one_work+0x7c0/0x14c0 kernel/workqueue.c:2116 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2250 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 -> #0 (&pool->lock/1){..-.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __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+0x174/0xf70 kernel/workqueue.c:1421 queue_work_on+0x159/0x1d0 kernel/workqueue.c:1490 pty_write+0x173/0x1c0 drivers/tty/pty.c:125 tty_put_char+0xfe/0x120 drivers/tty/tty_io.c:2880 do_output_char+0x126/0x750 drivers/tty/n_tty.c:488 __process_echoes+0x313/0x8c0 drivers/tty/n_tty.c:739 flush_echoes drivers/tty/n_tty.c:829 [inline] __receive_buf drivers/tty/n_tty.c:1648 [inline] n_tty_receive_buf_common+0x940/0x2490 drivers/tty/n_tty.c:1742 tiocsti drivers/tty/tty_io.c:2186 [inline] tty_ioctl+0xd5f/0x1220 drivers/tty/tty_io.c:2572 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 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 other info that might help us debug this: Chain exists of: &pool->lock/1 --> &port_lock_key --> &(&port->lock)->rlock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&port->lock)->rlock); lock(&port_lock_key); lock(&(&port->lock)->rlock); lock(&pool->lock/1); *** DEADLOCK *** 4 locks held by syz-executor.5/31539: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&o_tty->termios_rwsem/1){++++}, at: [] n_tty_receive_buf_common+0x81/0x2490 drivers/tty/n_tty.c:1705 #2: (&ldata->output_lock){+.+.}, at: [] flush_echoes drivers/tty/n_tty.c:827 [inline] #2: (&ldata->output_lock){+.+.}, at: [] __receive_buf drivers/tty/n_tty.c:1648 [inline] #2: (&ldata->output_lock){+.+.}, at: [] n_tty_receive_buf_common+0x902/0x2490 drivers/tty/n_tty.c:1742 #3: (&(&port->lock)->rlock){-.-.}, at: [] pty_write+0xdb/0x1c0 drivers/tty/pty.c:120 stack backtrace: CPU: 1 PID: 31539 Comm: syz-executor.5 Not tainted 4.14.184-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+0x1b2/0x283 lib/dump_stack.c:58 print_circular_bug.isra.0.cold+0x2dc/0x425 kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x3057/0x42a0 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __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+0x174/0xf70 kernel/workqueue.c:1421 queue_work_on+0x159/0x1d0 kernel/workqueue.c:1490 pty_write+0x173/0x1c0 drivers/tty/pty.c:125 tty_put_char+0xfe/0x120 drivers/tty/tty_io.c:2880 do_output_char+0x126/0x750 drivers/tty/n_tty.c:488 __process_echoes+0x313/0x8c0 drivers/tty/n_tty.c:739 flush_echoes drivers/tty/n_tty.c:829 [inline] __receive_buf drivers/tty/n_tty.c:1648 [inline] n_tty_receive_buf_common+0x940/0x2490 drivers/tty/n_tty.c:1742 tiocsti drivers/tty/tty_io.c:2186 [inline] tty_ioctl+0xd5f/0x1220 drivers/tty/tty_io.c:2572 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 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: 0033:0x45ca59 RSP: 002b:00007f18d87a3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004ee9e0 RCX: 000000000045ca59 RDX: 0000000020000000 RSI: 0000000000005412 RDI: 0000000000000007 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000560 R14: 00000000004c818d R15: 00007f18d87a46d4 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.