Warning: Permanently added '10.128.0.54' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 44.317290][ T6806] IPVS: ftp: loaded support on port[0] = 21 [ 44.353173][ T6806] ttyprintk ttyprintk: tty_port_close_start: tty->count = 1 port count = 2 [ 44.362293][ C1] [ 44.362295][ C1] ====================================================== [ 44.362297][ C1] WARNING: possible circular locking dependency detected [ 44.362299][ C1] 5.8.0-rc7-syzkaller #0 Not tainted [ 44.362300][ C1] ------------------------------------------------------ [ 44.362302][ C1] syz-executor594/6806 is trying to acquire lock: [ 44.362304][ C1] ffffffff894e7950 (console_owner){-.-.}-{0:0}, at: console_lock_spinning_enable+0x2d/0x60 [ 44.362309][ C1] [ 44.362310][ C1] but task is already holding lock: [ 44.362312][ C1] ffffffff8c2e11f0 (&port->lock#2){-.-.}-{2:2}, at: tty_port_close_start+0x58/0x550 [ 44.362317][ C1] [ 44.362319][ C1] which lock already depends on the new lock. [ 44.362320][ C1] [ 44.362321][ C1] [ 44.362323][ C1] the existing dependency chain (in reverse order) is: [ 44.362323][ C1] [ 44.362324][ C1] -> #2 (&port->lock#2){-.-.}-{2:2}: [ 44.362330][ C1] lock_acquire+0x160/0x720 [ 44.362331][ C1] _raw_spin_lock_irqsave+0x9e/0xc0 [ 44.362333][ C1] tty_port_tty_get+0x21/0xe0 [ 44.362334][ C1] tty_port_default_wakeup+0x11/0x40 [ 44.362336][ C1] serial8250_tx_chars+0x5ea/0x800 [ 44.362337][ C1] serial8250_handle_irq+0x2fd/0x3e0 [ 44.362339][ C1] serial8250_default_handle_irq+0xac/0x190 [ 44.362340][ C1] serial8250_interrupt+0x93/0x180 [ 44.362342][ C1] __handle_irq_event_percpu+0x1b7/0x610 [ 44.362343][ C1] handle_irq_event+0xbd/0x280 [ 44.362345][ C1] handle_edge_irq+0x245/0xbf0 [ 44.362346][ C1] asm_call_on_stack+0xf/0x20 [ 44.362347][ C1] common_interrupt+0x155/0x260 [ 44.362349][ C1] asm_common_interrupt+0x1e/0x40 [ 44.362350][ C1] _raw_spin_unlock_irqrestore+0xa5/0xd0 [ 44.362351][ C1] uart_write+0x767/0x8f0 [ 44.362353][ C1] do_output_char+0x63b/0x940 [ 44.362354][ C1] n_tty_write+0xd5c/0x1170 [ 44.362355][ C1] tty_write+0x593/0x940 [ 44.362357][ C1] do_iter_write+0x402/0x540 [ 44.362358][ C1] do_writev+0x23f/0x4a0 [ 44.362359][ C1] do_syscall_64+0x73/0xe0 [ 44.362361][ C1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 44.362362][ C1] [ 44.362363][ C1] -> #1 (&port->lock){-.-.}-{2:2}: [ 44.362367][ C1] lock_acquire+0x160/0x720 [ 44.362369][ C1] _raw_spin_lock_irqsave+0x9e/0xc0 [ 44.362370][ C1] serial8250_console_write+0x13e/0xd60 [ 44.362372][ C1] console_unlock+0x90c/0xec0 [ 44.362373][ C1] vprintk_emit+0x1f8/0x3c0 [ 44.362374][ C1] printk+0x62/0x83 [ 44.362375][ C1] register_console+0x7ca/0xad0 [ 44.362377][ C1] univ8250_console_init+0x41/0x43 [ 44.362378][ C1] console_init+0x52/0x97 [ 44.362380][ C1] start_kernel+0x426/0x777 [ 44.362381][ C1] secondary_startup_64+0xa4/0xb0 [ 44.362382][ C1] [ 44.362383][ C1] -> #0 (console_owner){-.-.}-{0:0}: [ 44.362387][ C1] validate_chain+0x1b0c/0x8920 [ 44.362389][ C1] __lock_acquire+0x116c/0x2c30 [ 44.362390][ C1] lock_acquire+0x160/0x720 [ 44.362392][ C1] console_lock_spinning_enable+0x52/0x60 [ 44.362393][ C1] console_unlock+0x73f/0xec0 [ 44.362394][ C1] vprintk_emit+0x1f8/0x3c0 [ 44.362396][ C1] printk+0x62/0x83 [ 44.362397][ C1] tty_port_close_start+0x3c8/0x550 [ 44.362398][ C1] tty_port_close+0x25/0x140 [ 44.362400][ C1] tty_release+0x378/0xf90 [ 44.362401][ C1] __fput+0x2f0/0x750 [ 44.362402][ C1] task_work_run+0x137/0x1c0 [ 44.362404][ C1] __prepare_exit_to_usermode+0x14c/0x1e0 [ 44.362405][ C1] do_syscall_64+0x7f/0xe0 [ 44.362407][ C1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 44.362407][ C1] [ 44.362409][ C1] other info that might help us debug this: [ 44.362410][ C1] [ 44.362411][ C1] Chain exists of: [ 44.362412][ C1] console_owner --> &port->lock --> &port->lock#2 [ 44.362418][ C1] [ 44.362420][ C1] Possible unsafe locking scenario: [ 44.362420][ C1] [ 44.362422][ C1] CPU0 CPU1 [ 44.362423][ C1] ---- ---- [ 44.362424][ C1] lock(&port->lock#2); [ 44.362428][ C1] lock(&port->lock); [ 44.362431][ C1] lock(&port->lock#2); [ 44.362434][ C1] lock(console_owner); [ 44.362437][ C1] [ 44.362438][ C1] *** DEADLOCK *** [ 44.362439][ C1] [ 44.362440][ C1] 3 locks held by syz-executor594/6806: [ 44.362441][ C1] #0: ffff8880a1df01c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_release+0xa5/0xf90 [ 44.362447][ C1] #1: ffffffff8c2e11f0 (&port->lock#2){-.-.}-{2:2}, at: tty_port_close_start+0x58/0x550 [ 44.362453][ C1] #2: ffffffff894e7830 (console_lock){+.+.}-{0:0}, at: vprintk_emit+0x1db/0x3c0 [ 44.362459][ C1] [ 44.362460][ C1] stack backtrace: [ 44.362462][ C1] CPU: 1 PID: 6806 Comm: syz-executor594 Not tainted 5.8.0-rc7-syzkaller #0 [ 44.362464][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.362465][ C1] Call Trace: [ 44.362467][ C1] dump_stack+0x1f0/0x31e [ 44.362468][ C1] print_circular_bug+0xc72/0xea0 [ 44.362469][ C1] ? stack_trace_save+0xad/0x150 [ 44.362470][ C1] ? save_trace+0x49/0xba0 [ 44.362472][ C1] check_noncircular+0x1fb/0x3a0 [ 44.362480][ C1] validate_chain+0x1b0c/0x8920 [ 44.362481][ C1] ? mark_lock+0x102/0x1b00 [ 44.362482][ C1] ? mark_lock+0x102/0x1b00 [ 44.362483][ C1] ? put_dec_trunc8+0x19a/0x290 [ 44.362484][ C1] ? number+0xf14/0x1190 [ 44.362486][ C1] __lock_acquire+0x116c/0x2c30 [ 44.362487][ C1] ? sprintf+0x71/0x90 [ 44.362488][ C1] lock_acquire+0x160/0x720 [ 44.362490][ C1] ? console_lock_spinning_enable+0x2d/0x60 [ 44.362491][ C1] console_lock_spinning_enable+0x52/0x60 [ 44.362493][ C1] ? console_lock_spinning_enable+0x2d/0x60 [ 44.362494][ C1] console_unlock+0x73f/0xec0 [ 44.362496][ C1] ? __down_trylock_console_sem+0x178/0x1b0 [ 44.362497][ C1] ? vprintk_emit+0x1db/0x3c0 [ 44.362498][ C1] ? vprintk_emit+0x1db/0x3c0 [ 44.362499][ C1] vprintk_emit+0x1f8/0x3c0 [ 44.362501][ C1] printk+0x62/0x83 [ 44.362502][ C1] tty_port_close_start+0x3c8/0x550 [ 44.362503][ C1] tty_port_close+0x25/0x140 [ 44.362504][ C1] ? tpk_open+0x60/0x60 [ 44.362506][ C1] tty_release+0x378/0xf90 [ 44.362507][ C1] ? fsnotify+0x128d/0x1340 [ 44.362508][ C1] ? ima_file_free+0xea/0x3b0 [ 44.362510][ C1] ? tty_release_struct+0xd0/0xd0 [ 44.362511][ C1] __fput+0x2f0/0x750 [ 44.362512][ C1] task_work_run+0x137/0x1c0 [ 44.362513][ C1] __prepare_exit_to_usermode+0x14c/0x1e0 [ 44.362515][ C1] ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 44.362516][ C1] do_syscall_64+0x7f/0xe0 [ 44.362517][ C1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 44.362519][ C1] RIP: 0033:0x405701 [ 44.362523][ C1] Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 83 ec 08 e8 6a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 b3 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 [ 44.362524][ C1] RSP: 002b:00007ffef5148d30 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 [ 44.362528][ C1] RAX: 0000000000000000 RBX: 00007ffef5148d60 RCX: 0000000000405701 [ 44.362530][ C1] RDX: 0000