====================================================== WARNING: possible circular locking dependency detected 5.17.0-rc5-next-20220222-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/4082 is trying to acquire lock: ffff8880b9d395d8 (&pool->lock){-.-.}-{2:2}, at: __queue_work+0x366/0x1140 kernel/workqueue.c:1474 but task is already holding lock: ffff88801d399528 (&tty->write_wait){-.-.}-{2:2}, at: __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&tty->write_wait){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 tty_port_default_wakeup+0x26/0x40 drivers/tty/tty_port.c:51 serial8250_tx_chars+0x4f3/0xad0 drivers/tty/serial/8250/8250_port.c:1853 serial8250_handle_irq.part.0+0x328/0x3d0 drivers/tty/serial/8250/8250_port.c:1940 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1913 [inline] serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1957 serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0x22b/0x880 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] handle_irq_event+0xa7/0x1e0 kernel/irq/handle.c:210 handle_edge_irq+0x25f/0xd00 kernel/irq/chip.c:817 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline] handle_irq arch/x86/kernel/irq.c:231 [inline] __common_interrupt+0x9d/0x210 arch/x86/kernel/irq.c:250 common_interrupt+0xa4/0xc0 arch/x86/kernel/irq.c:240 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] acpi_safe_halt drivers/acpi/processor_idle.c:115 [inline] acpi_idle_do_entry+0x1c6/0x250 drivers/acpi/processor_idle.c:556 acpi_idle_enter+0x361/0x500 drivers/acpi/processor_idle.c:692 cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x3e8/0x590 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_kernel+0x47f/0x4a0 init/main.c:1140 secondary_startup_64_no_verify+0xc3/0xcb -> #2 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162 serial8250_console_write+0x91a/0xb70 drivers/tty/serial/8250/8250_port.c:3359 call_console_drivers kernel/printk/printk.c:1953 [inline] console_unlock+0x9bc/0xdd0 kernel/printk/printk.c:2775 vprintk_emit+0x1b4/0x5f0 kernel/printk/printk.c:2273 vprintk+0x80/0x90 kernel/printk/printk_safe.c:50 _printk+0xba/0xed kernel/printk/printk.c:2294 register_console kernel/printk/printk.c:3132 [inline] register_console+0x410/0x7c0 kernel/printk/printk.c:3013 univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:679 console_init+0x3c1/0x58d kernel/printk/printk.c:3232 start_kernel+0x30b/0x4a0 init/main.c:1068 secondary_startup_64_no_verify+0xc3/0xcb -> #1 (console_owner){....}-{0:0}: console_lock_spinning_enable kernel/printk/printk.c:1795 [inline] console_unlock+0x3b1/0xdd0 kernel/printk/printk.c:2772 vprintk_emit+0x1b4/0x5f0 kernel/printk/printk.c:2273 vprintk+0x80/0x90 kernel/printk/printk_safe.c:50 _printk+0xba/0xed kernel/printk/printk.c:2294 warn_flush_attempt kernel/workqueue.c:2613 [inline] check_flush_dependency.cold+0x18/0x4e kernel/workqueue.c:2635 start_flush_work kernel/workqueue.c:3049 [inline] __flush_work+0x25a/0xb10 kernel/workqueue.c:3091 flush_all_cpus_locked+0x148/0x1b0 mm/slub.c:2728 flush_all mm/slub.c:2737 [inline] __kmem_cache_shrink+0x11/0x20 mm/slub.c:4640 acpi_os_purge_cache+0x11/0x20 drivers/acpi/osl.c:1666 acpi_purge_cached_objects+0x37/0xd0 drivers/acpi/acpica/utxface.c:237 acpi_initialize_objects+0x2b/0x95 drivers/acpi/acpica/utxfinit.c:250 acpi_bus_init drivers/acpi/bus.c:1237 [inline] acpi_init+0x1d2/0x976 drivers/acpi/bus.c:1325 do_one_initcall+0x103/0x650 init/main.c:1302 do_initcall_level init/main.c:1375 [inline] do_initcalls init/main.c:1391 [inline] do_basic_setup init/main.c:1410 [inline] kernel_init_freeable+0x6b1/0x73a init/main.c:1615 kernel_init+0x1a/0x1d0 init/main.c:1504 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 -> #0 (&pool->lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3096 [inline] check_prevs_add kernel/locking/lockdep.c:3219 [inline] validate_chain kernel/locking/lockdep.c:3834 [inline] __lock_acquire+0x2ac6/0x56c0 kernel/locking/lockdep.c:5060 lock_acquire kernel/locking/lockdep.c:5672 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5637 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 __queue_work+0x366/0x1140 kernel/workqueue.c:1474 queue_work_on+0xee/0x110 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:514 [inline] schedule_work include/linux/workqueue.h:575 [inline] p9_pollwake+0xbd/0x1c0 net/9p/trans_fd.c:534 __wake_up_common+0x147/0x650 kernel/sched/wait.c:108 __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:138 __start_tty drivers/tty/tty_io.c:796 [inline] __start_tty drivers/tty/tty_io.c:789 [inline] start_tty+0x111/0x150 drivers/tty/tty_io.c:815 n_tty_receive_char+0x3c2/0x5b0 drivers/tty/n_tty.c:1374 n_tty_receive_buf_standard drivers/tty/n_tty.c:1532 [inline] __receive_buf drivers/tty/n_tty.c:1549 [inline] n_tty_receive_buf_common+0x109e/0x4780 drivers/tty/n_tty.c:1645 tiocsti drivers/tty/tty_io.c:2293 [inline] tty_ioctl+0x909/0x15e0 drivers/tty/tty_io.c:2692 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: &pool->lock --> &port_lock_key --> &tty->write_wait Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&tty->write_wait); lock(&port_lock_key); lock(&tty->write_wait); lock(&pool->lock); *** DEADLOCK *** 6 locks held by syz-executor.1/4082: #0: ffff88801d399098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244 #1: ffff88801d39a0b8 (&buf->lock){+.+.}-{3:3}, at: tiocsti drivers/tty/tty_io.c:2291 [inline] #1: ffff88801d39a0b8 (&buf->lock){+.+.}-{3:3}, at: tty_ioctl+0x89f/0x15e0 drivers/tty/tty_io.c:2692 #2: ffff88801d3992e8 (&tty->termios_rwsem){++++}-{3:3}, at: n_tty_receive_buf_common+0x84/0x4780 drivers/tty/n_tty.c:1608 #3: ffff88801d399468 (&tty->flow.lock){....}-{2:2}, at: start_tty+0x1d/0x150 drivers/tty/tty_io.c:814 #4: ffff88801d399528 (&tty->write_wait){-.-.}-{2:2}, at: __wake_up_common_lock+0xb4/0x130 kernel/sched/wait.c:137 #5: ffffffff8bb866a0 (rcu_read_lock){....}-{1:2}, at: __queue_work+0xd0/0x1140 kernel/workqueue.c:1437 stack backtrace: CPU: 1 PID: 4082 Comm: syz-executor.1 Not tainted 5.17.0-rc5-next-20220222-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2176 check_prev_add kernel/locking/lockdep.c:3096 [inline] check_prevs_add kernel/locking/lockdep.c:3219 [inline] validate_chain kernel/locking/lockdep.c:3834 [inline] __lock_acquire+0x2ac6/0x56c0 kernel/locking/lockdep.c:5060 lock_acquire kernel/locking/lockdep.c:5672 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5637 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 __queue_work+0x366/0x1140 kernel/workqueue.c:1474 queue_work_on+0xee/0x110 kernel/workqueue.c:1545 queue_work include/linux/workqueue.h:514 [inline] schedule_work include/linux/workqueue.h:575 [inline] p9_pollwake+0xbd/0x1c0 net/9p/trans_fd.c:534 __wake_up_common+0x147/0x650 kernel/sched/wait.c:108 __wake_up_common_lock+0xd0/0x130 kernel/sched/wait.c:138 __start_tty drivers/tty/tty_io.c:796 [inline] __start_tty drivers/tty/tty_io.c:789 [inline] start_tty+0x111/0x150 drivers/tty/tty_io.c:815 n_tty_receive_char+0x3c2/0x5b0 drivers/tty/n_tty.c:1374 n_tty_receive_buf_standard drivers/tty/n_tty.c:1532 [inline] __receive_buf drivers/tty/n_tty.c:1549 [inline] n_tty_receive_buf_common+0x109e/0x4780 drivers/tty/n_tty.c:1645 tiocsti drivers/tty/tty_io.c:2293 [inline] tty_ioctl+0x909/0x15e0 drivers/tty/tty_io.c:2692 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f4216089059 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4217124168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f421619c030 RCX: 00007f4216089059 RDX: 0000000020000100 RSI: 0000000000005412 RDI: 0000000000000004 RBP: 00007f42160e308d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffe7e5859f R14: 00007f4217124300 R15: 0000000000022000