RBP: 00007f4031b171d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fffbd47650f R14: 00007f4031b17300 R15: 0000000000022000 ====================================================== WARNING: possible circular locking dependency detected 5.10.154 #1 Not tainted ------------------------------------------------------ syz-executor.1/49619 is trying to acquire lock: ffffffff84f0c300 (console_owner){-.-.}-{0:0}, at: console_unlock+0x2e1/0xb40 kernel/printk/printk.c:2507 but task is already holding lock: ffff888016cb1bd8 (&sighand->siglock){-.-.}-{2:2}, at: __lock_task_sighand+0xd3/0x2f0 kernel/signal.c:1391 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&sighand->siglock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x60 kernel/locking/spinlock.c:159 __lock_task_sighand+0xd3/0x2f0 kernel/signal.c:1391 lock_task_sighand include/linux/sched/signal.h:693 [inline] task_work_add+0x1df/0x2b0 kernel/task_work.c:58 io_req_task_work_add fs/io_uring.c:2069 [inline] __io_async_wake+0x40b/0x8d0 fs/io_uring.c:4949 __wake_up_common+0x14c/0x4c0 kernel/sched/wait.c:93 __wake_up_common_lock+0xd0/0x140 kernel/sched/wait.c:123 tty_ldisc_lock+0x40/0xb0 drivers/tty/tty_ldisc.c:335 tty_ldisc_hangup+0x204/0x690 drivers/tty/tty_ldisc.c:744 __tty_hangup.part.0+0x510/0x9b0 drivers/tty/tty_io.c:624 __tty_hangup drivers/tty/tty_io.c:574 [inline] tty_vhangup drivers/tty/tty_io.c:697 [inline] tty_ioctl+0x1212/0x1840 drivers/tty/tty_io.c:2683 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xc6 -> #3 (&tty->read_wait){....}-{2:2}: __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x27/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] io_poll_double_wake+0x1f8/0x550 fs/io_uring.c:5062 __wake_up_common+0x14c/0x4c0 kernel/sched/wait.c:93 __wake_up_common_lock+0xd0/0x140 kernel/sched/wait.c:123 tty_ldisc_lock+0x55/0xb0 drivers/tty/tty_ldisc.c:336 tty_ldisc_hangup+0x204/0x690 drivers/tty/tty_ldisc.c:744 __tty_hangup.part.0+0x510/0x9b0 drivers/tty/tty_io.c:624 __tty_hangup drivers/tty/tty_io.c:574 [inline] tty_vhangup drivers/tty/tty_io.c:697 [inline] tty_ioctl+0x1212/0x1840 drivers/tty/tty_io.c:2683 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xc6 -> #2 (&tty->write_wait){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x60 kernel/locking/spinlock.c:159 __wake_up_common_lock+0xb4/0x140 kernel/sched/wait.c:122 tty_port_default_wakeup+0x26/0x40 drivers/tty/tty_port.c:50 serial8250_tx_chars+0x51f/0xb00 drivers/tty/serial/8250/8250_port.c:1845 serial8250_handle_irq.part.0+0x3ec/0x4c0 drivers/tty/serial/8250/8250_port.c:1932 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1905 [inline] serial8250_default_handle_irq+0xb8/0x230 drivers/tty/serial/8250/8250_port.c:1948 serial8250_interrupt+0xf4/0x1b0 drivers/tty/serial/8250/8250_core.c:127 __handle_irq_event_percpu+0x2ef/0x820 kernel/irq/handle.c:156 handle_irq_event_percpu kernel/irq/handle.c:196 [inline] handle_irq_event+0xff/0x280 kernel/irq/handle.c:213 handle_edge_irq+0x249/0xd00 kernel/irq/chip.c:822 asm_call_irq_on_stack+0x12/0x20 __run_irq_on_irqstack arch/x86/include/asm/irq_stack.h:48 [inline] run_irq_on_irqstack_cond arch/x86/include/asm/irq_stack.h:101 [inline] handle_irq arch/x86/kernel/irq.c:230 [inline] __common_interrupt arch/x86/kernel/irq.c:249 [inline] common_interrupt+0xdd/0x190 arch/x86/kernel/irq.c:239 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:626 native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline] arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irqrestore+0x25/0x40 kernel/locking/spinlock.c:191 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline] uart_write+0x304/0x580 drivers/tty/serial/serial_core.c:614 do_output_char+0x5e8/0x870 drivers/tty/n_tty.c:442 process_output drivers/tty/n_tty.c:509 [inline] n_tty_write+0x487/0xf90 drivers/tty/n_tty.c:2395 do_tty_write drivers/tty/tty_io.c:1028 [inline] file_tty_write.constprop.0+0x4f8/0x8d0 drivers/tty/tty_io.c:1118 redirected_tty_write+0xa5/0xd0 drivers/tty/tty_io.c:1125 call_write_iter include/linux/fs.h:1904 [inline] do_iter_readv_writev+0x476/0x750 fs/read_write.c:740 do_iter_write+0x191/0x670 fs/read_write.c:866 vfs_writev+0x1ae/0x5e0 fs/read_write.c:939 do_writev+0x139/0x300 fs/read_write.c:982 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xc6 -> #1 (&port_lock_key){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x36/0x60 kernel/locking/spinlock.c:159 serial8250_console_write+0x9f5/0xc60 drivers/tty/serial/8250/8250_port.c:3333 call_console_drivers kernel/printk/printk.c:1911 [inline] console_unlock+0x82a/0xb40 kernel/printk/printk.c:2532 register_console kernel/printk/printk.c:2873 [inline] register_console+0x53d/0x800 kernel/printk/printk.c:2763 univ8250_console_init+0x3a/0x4a drivers/tty/serial/8250/8250_core.c:700 console_init+0x361/0x4fa kernel/printk/printk.c:2983 start_kernel+0x2e1/0x48e init/main.c:982 secondary_startup_64_no_verify+0xc2/0xcb -> #0 (console_owner){-.-.}-{0:0}: check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3728 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4954 lock_acquire kernel/locking/lockdep.c:5565 [inline] lock_acquire+0x197/0x490 kernel/locking/lockdep.c:5530 console_lock_spinning_enable kernel/printk/printk.c:1763 [inline] console_unlock+0x360/0xb40 kernel/printk/printk.c:2529 vprintk_emit+0x1de/0x4d0 kernel/printk/printk.c:2054 vprintk_func+0x8b/0x140 kernel/printk/printk_safe.c:401 printk+0xba/0xf1 kernel/printk/printk.c:2102 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x47a/0x5a0 lib/fault-inject.c:146 should_failslab+0x5/0x20 mm/slab_common.c:1193 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2904 [inline] kmem_cache_alloc+0x5b/0x360 mm/slub.c:2909 __sigqueue_alloc+0x1ee/0x560 kernel/signal.c:435 __send_signal+0x5e2/0x1040 kernel/signal.c:1116 do_send_sig_info kernel/signal.c:1291 [inline] group_send_sig_info+0x277/0x2d0 kernel/signal.c:1414 __kill_pgrp_info+0x88/0x120 kernel/signal.c:1432 kill_pgrp+0x3a/0x60 kernel/signal.c:1786 __isig drivers/tty/n_tty.c:1111 [inline] isig+0x10a/0x430 drivers/tty/n_tty.c:1128 n_tty_receive_signal_char+0x1f/0x150 drivers/tty/n_tty.c:1238 n_tty_receive_char_special+0x1277/0x2aa0 drivers/tty/n_tty.c:1290 n_tty_receive_buf_standard drivers/tty/n_tty.c:1579 [inline] __receive_buf drivers/tty/n_tty.c:1641 [inline] n_tty_receive_buf_common+0xa33/0x2b80 drivers/tty/n_tty.c:1737 tiocsti drivers/tty/tty_io.c:2277 [inline] tty_ioctl+0x51b/0x1840 drivers/tty/tty_io.c:2658 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xc6 other info that might help us debug this: Chain exists of: console_owner --> &tty->read_wait --> &sighand->siglock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sighand->siglock); lock(&tty->read_wait); lock(&sighand->siglock); lock(console_owner); *** DEADLOCK *** 6 locks held by syz-executor.1/49619: #0: ffff88801ae95098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x90 drivers/tty/tty_ldisc.c:266 #1: ffff888007c690b8 (&buf->lock){+.+.}-{3:3}, at: tiocsti drivers/tty/tty_io.c:2275 [inline] #1: ffff888007c690b8 (&buf->lock){+.+.}-{3:3}, at: tty_ioctl+0x4ae/0x1840 drivers/tty/tty_io.c:2658 #2: ffff88801ae952e8 (&tty->termios_rwsem){++++}-{3:3}, at: isig+0xe5/0x430 drivers/tty/n_tty.c:1126 #3: ffffffff84e0a098 (tasklist_lock){.+.?}-{2:2}, at: kill_pgrp+0x1e/0x60 kernel/signal.c:1785 #4: ffff888016cb1bd8 (&sighand->siglock){-.-.}-{2:2}, at: __lock_task_sighand+0xd3/0x2f0 kernel/signal.c:1391 #5: ffffffff84fec680 (console_lock){+.+.}-{0:0}, at: vprintk_func+0x8b/0x140 kernel/printk/printk_safe.c:401 stack backtrace: CPU: 1 PID: 49619 Comm: syz-executor.1 Not tainted 5.10.154 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 check_noncircular+0x263/0x2e0 kernel/locking/lockdep.c:2123 check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3728 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4954 lock_acquire kernel/locking/lockdep.c:5565 [inline] lock_acquire+0x197/0x490 kernel/locking/lockdep.c:5530 console_lock_spinning_enable kernel/printk/printk.c:1763 [inline] console_unlock+0x360/0xb40 kernel/printk/printk.c:2529 vprintk_emit+0x1de/0x4d0 kernel/printk/printk.c:2054 vprintk_func+0x8b/0x140 kernel/printk/printk_safe.c:401 printk+0xba/0xf1 kernel/printk/printk.c:2102 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x47a/0x5a0 lib/fault-inject.c:146 should_failslab+0x5/0x20 mm/slab_common.c:1193 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2904 [inline] kmem_cache_alloc+0x5b/0x360 mm/slub.c:2909 __sigqueue_alloc+0x1ee/0x560 kernel/signal.c:435 __send_signal+0x5e2/0x1040 kernel/signal.c:1116 do_send_sig_info kernel/signal.c:1291 [inline] group_send_sig_info+0x277/0x2d0 kernel/signal.c:1414 __kill_pgrp_info+0x88/0x120 kernel/signal.c:1432 kill_pgrp+0x3a/0x60 kernel/signal.c:1786 __isig drivers/tty/n_tty.c:1111 [inline] isig+0x10a/0x430 drivers/tty/n_tty.c:1128 n_tty_receive_signal_char+0x1f/0x150 drivers/tty/n_tty.c:1238 n_tty_receive_char_special+0x1277/0x2aa0 drivers/tty/n_tty.c:1290 n_tty_receive_buf_standard drivers/tty/n_tty.c:1579 [inline] __receive_buf drivers/tty/n_tty.c:1641 [inline] n_tty_receive_buf_common+0xa33/0x2b80 drivers/tty/n_tty.c:1737 tiocsti drivers/tty/tty_io.c:2277 [inline] tty_ioctl+0x51b/0x1840 drivers/tty/tty_io.c:2658 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xc6 RIP: 0033:0x7f40345a1b19 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4031b17188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f40346b4f60 RCX: 00007f40345a1b19 RDX: 0000000020001400 RSI: 0000000000005412 RDI: 0000000000000003 RBP: 00007f4031b171d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fffbd47650f R14: 00007f4031b17300 R15: 0000000000022000