R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000074 R14: 00000000004c2d06 R15: 0000000000000002 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 ====================================================== WARNING: possible circular locking dependency detected 4.19.108-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/5644 is trying to acquire lock: 00000000a416d4be (console_owner){-...}, at: console_trylock_spinning kernel/printk/printk.c:1669 [inline] 00000000a416d4be (console_owner){-...}, at: vprintk_emit+0x3d8/0x6e0 kernel/printk/printk.c:1936 but task is already holding lock: 00000000aa8f1933 (&(&port->lock)->rlock){-.-.}, at: tty_port_close_start.part.0+0x28/0x540 drivers/tty/tty_port.c:574 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&(&port->lock)->rlock){-.-.}: tty_port_tty_get+0x1d/0x80 drivers/tty/tty_port.c:289 tty_port_default_wakeup+0x11/0x40 drivers/tty/tty_port.c:47 serial8250_tx_chars+0x48f/0xae0 drivers/tty/serial/8250/8250_port.c:1806 serial8250_handle_irq.part.0+0x24b/0x290 drivers/tty/serial/8250/8250_port.c:1879 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1865 [inline] serial8250_default_handle_irq+0xb5/0x140 drivers/tty/serial/8250/8250_port.c:1895 serial8250_interrupt+0xf2/0x1d0 drivers/tty/serial/8250/8250_core.c:125 __handle_irq_event_percpu+0x144/0x8e0 kernel/irq/handle.c:149 handle_irq_event_percpu+0x76/0x160 kernel/irq/handle.c:189 handle_irq_event+0xa2/0x12d kernel/irq/handle.c:206 handle_edge_irq+0x24b/0x8c0 kernel/irq/chip.c:797 generic_handle_irq_desc include/linux/irqdesc.h:155 [inline] handle_irq+0x35/0x50 arch/x86/kernel/irq_64.c:87 do_IRQ+0x93/0x1c0 arch/x86/kernel/irq.c:246 ret_from_intr+0x0/0x1e arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x91/0xe0 kernel/locking/spinlock.c:184 spin_unlock_irqrestore include/linux/spinlock.h:384 [inline] uart_write+0x365/0x680 drivers/tty/serial/serial_core.c:612 process_output_block drivers/tty/n_tty.c:593 [inline] n_tty_write+0x3ee/0x1080 drivers/tty/n_tty.c:2331 do_tty_write drivers/tty/tty_io.c:960 [inline] tty_write+0x452/0x790 drivers/tty/tty_io.c:1044 redirected_tty_write+0xaa/0xb0 drivers/tty/tty_io.c:1065 __vfs_write+0xf7/0x760 fs/read_write.c:485 vfs_write+0x206/0x550 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&port_lock_key){-.-.}: serial8250_console_write+0x79f/0x9c0 drivers/tty/serial/8250/8250_port.c:3251 call_console_drivers kernel/printk/printk.c:1736 [inline] console_unlock+0xb26/0xfe0 kernel/printk/printk.c:2429 vprintk_emit+0x282/0x6e0 kernel/printk/printk.c:1937 vprintk_func+0x79/0x17e kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 register_console+0x752/0xb50 kernel/printk/printk.c:2745 univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:684 console_init+0x4cb/0x718 kernel/printk/printk.c:2831 start_kernel+0x594/0x81c init/main.c:660 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 -> #0 (console_owner){-...}: console_trylock_spinning kernel/printk/printk.c:1690 [inline] vprintk_emit+0x415/0x6e0 kernel/printk/printk.c:1936 vprintk_func+0x79/0x17e kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 tty_port_close_start.part.0+0x4f0/0x540 drivers/tty/tty_port.c:576 tty_port_close_start drivers/tty/tty_port.c:648 [inline] tty_port_close+0x46/0xe0 drivers/tty/tty_port.c:641 tty_release+0x3b9/0xe90 drivers/tty/tty_io.c:1678 __fput+0x2cd/0x890 fs/file_table.c:278 task_work_run+0x13f/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x25a/0x2b0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: console_owner --> &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(console_owner); *** DEADLOCK *** 2 locks held by syz-executor.4/5644: #0: 00000000a49b3095 (&tty->legacy_mutex){+.+.}, at: tty_lock+0x6a/0xa0 drivers/tty/tty_mutex.c:19 #1: 00000000aa8f1933 (&(&port->lock)->rlock){-.-.}, at: tty_port_close_start.part.0+0x28/0x540 drivers/tty/tty_port.c:574 stack backtrace: CPU: 0 PID: 5644 Comm: syz-executor.4 Not tainted 4.19.108-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 print_circular_bug.isra.0.cold+0x1c4/0x282 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+0x170/0x400 kernel/locking/lockdep.c:3903 console_trylock_spinning kernel/printk/printk.c:1690 [inline] vprintk_emit+0x415/0x6e0 kernel/printk/printk.c:1936 vprintk_func+0x79/0x17e kernel/printk/printk_safe.c:398 printk+0xba/0xed kernel/printk/printk.c:2012 tty_port_close_start.part.0+0x4f0/0x540 drivers/tty/tty_port.c:576 tty_port_close_start drivers/tty/tty_port.c:648 [inline] tty_port_close+0x46/0xe0 drivers/tty/tty_port.c:641 tty_release+0x3b9/0xe90 drivers/tty/tty_io.c:1678 __fput+0x2cd/0x890 fs/file_table.c:278 task_work_run+0x13f/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x25a/0x2b0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x416011 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fffea5c28b0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000416011 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000770120 R09: 01ffffffffffffff R10: 00007fffea5c2980 R11: 0000000000000293 R12: 000000000076bf20 R13: 0000000000770128 R14: 0000000000000000 R15: 000000000076bf2c CPU: 0 PID: 5947 Comm: syz-executor.5 Not tainted 4.19.108-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold+0xa/0x1b lib/fault-inject.c:149 __should_failslab+0x115/0x180 mm/failslab.c:32 should_failslab+0x5/0xf mm/slab_common.c:1558 slab_pre_alloc_hook mm/slab.h:424 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x29f/0x710 mm/slab.c:3557 prepare_creds+0x39/0x410 kernel/cred.c:255 copy_creds+0x72/0x5f0 kernel/cred.c:348 copy_process.part.0+0xb78/0x7a60 kernel/fork.c:1770 copy_process kernel/fork.c:1694 [inline] _do_fork+0x22f/0xf40 kernel/fork.c:2207 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c479 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fee91fddc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fee91fde6d4 RCX: 000000000045c479 RDX: 9999999999999999 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000000076bf20 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000074 R14: 00000000004c2d06 R15: 0000000000000003 9pnet_virtio: no channels available for device syz caif:caif_disconnect_client(): nothing to disconnect ttyprintk ttyprintk: tty_port_close_start: tty->count = 1 port count = 3 IPVS: Error connecting to the multicast addr IPVS: Error connecting to the multicast addr IPVS: Error connecting to the multicast addr IPVS: Error connecting to the multicast addr IPVS: Error connecting to the multicast addr IPVS: Error connecting to the multicast addr IPVS: Error connecting to the multicast addr QAT: Invalid ioctl IPVS: Error connecting to the multicast addr IPVS: Error connecting to the multicast addr