FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 ====================================================== WARNING: possible circular locking dependency detected 5.15.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.3/22669 is trying to acquire lock: ffffffff8b88ff80 (console_owner){-.-.}-{0:0}, at: console_unlock+0x303/0xb70 kernel/printk/printk.c:2707 but task is already holding lock: ffff88807a311958 (&port->lock){-.-.}-{2:2}, at: pty_write+0xea/0x1e0 drivers/tty/pty.c:120 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&port->lock){-.-.}-{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 tty_port_tty_get+0x1f/0x100 drivers/tty/tty_port.c:289 tty_port_default_wakeup+0x11/0x40 drivers/tty/tty_port.c:48 serial8250_tx_chars+0x4f3/0xad0 drivers/tty/serial/8250/8250_port.c:1845 serial8250_handle_irq.part.0+0x328/0x3d0 drivers/tty/serial/8250/8250_port.c:1932 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1905 [inline] serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1949 serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126 __handle_irq_event_percpu+0x303/0x8f0 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:198 [inline] handle_irq_event+0x102/0x280 kernel/irq/handle.c:215 handle_edge_irq+0x25f/0xd00 kernel/irq/chip.c:822 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 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:405 [inline] uart_write+0x30d/0x570 drivers/tty/serial/serial_core.c:598 do_output_char+0x5de/0x850 drivers/tty/n_tty.c:444 process_output drivers/tty/n_tty.c:511 [inline] n_tty_write+0x4c3/0xfd0 drivers/tty/n_tty.c:2300 do_tty_write drivers/tty/tty_io.c:1038 [inline] file_tty_write.constprop.0+0x526/0x910 drivers/tty/tty_io.c:1110 redirected_tty_write+0xa1/0xc0 drivers/tty/tty_io.c:1131 call_write_iter include/linux/fs.h:2162 [inline] do_iter_readv_writev+0x472/0x750 fs/read_write.c:725 do_iter_write+0x188/0x710 fs/read_write.c:851 vfs_writev+0x1aa/0x630 fs/read_write.c:924 do_writev+0x139/0x300 fs/read_write.c:967 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 -> #1 (&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:3358 call_console_drivers kernel/printk/printk.c:1929 [inline] console_unlock+0x7a9/0xb70 kernel/printk/printk.c:2711 vprintk_emit+0x198/0x4f0 kernel/printk/printk.c:2245 vprintk+0x80/0x90 kernel/printk/printk_safe.c:50 _printk+0xba/0xed kernel/printk/printk.c:2266 register_console kernel/printk/printk.c:3051 [inline] register_console+0x55f/0x780 kernel/printk/printk.c:2931 univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:680 console_init+0x3c1/0x58d kernel/printk/printk.c:3151 start_kernel+0x30b/0x49b init/main.c:1062 secondary_startup_64_no_verify+0xb0/0xbb -> #0 (console_owner){-.-.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3066 [inline] check_prevs_add kernel/locking/lockdep.c:3189 [inline] validate_chain kernel/locking/lockdep.c:3804 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5030 lock_acquire kernel/locking/lockdep.c:5640 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605 console_lock_spinning_enable kernel/printk/printk.c:1781 [inline] console_unlock+0x356/0xb70 kernel/printk/printk.c:2708 vprintk_emit+0x198/0x4f0 kernel/printk/printk.c:2245 vprintk+0x80/0x90 kernel/printk/printk_safe.c:50 _printk+0xba/0xed kernel/printk/printk.c:2266 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x472/0x5a0 lib/fault-inject.c:146 should_failslab+0x5/0x10 mm/slab_common.c:1320 slab_pre_alloc_hook mm/slab.h:494 [inline] slab_alloc mm/slab.c:3306 [inline] __do_kmalloc mm/slab.c:3700 [inline] __kmalloc+0x7b/0x4d0 mm/slab.c:3711 kmalloc include/linux/slab.h:595 [inline] tty_buffer_alloc+0x23f/0x2a0 drivers/tty/tty_buffer.c:177 __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:275 tty_insert_flip_string_fixed_flag+0x93/0x250 drivers/tty/tty_buffer.c:321 tty_insert_flip_string include/linux/tty_flip.h:42 [inline] pty_write+0x11c/0x1e0 drivers/tty/pty.c:122 tty_send_xchar+0x251/0x370 drivers/tty/tty_io.c:1182 n_tty_ioctl_helper+0x179/0x2d0 drivers/tty/tty_ioctl.c:890 n_tty_ioctl+0x4b/0x360 drivers/tty/n_tty.c:2421 tty_ioctl+0xc69/0x1670 drivers/tty/tty_io.c:2814 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: console_owner --> &port_lock_key --> &port->lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&port->lock); lock(&port_lock_key); lock(&port->lock); lock(console_owner); *** DEADLOCK *** 5 locks held by syz-executor.3/22669: #0: ffff8880739da098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffff8880739da130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_write_lock drivers/tty/tty_io.c:961 [inline] #1: ffff8880739da130 (&tty->atomic_write_lock){+.+.}-{3:3}, at: tty_send_xchar+0x1a1/0x370 drivers/tty/tty_io.c:1176 #2: ffff8880739da2e8 (&o_tty->termios_rwsem/1){++++}-{3:3}, at: tty_send_xchar+0x1ea/0x370 drivers/tty/tty_io.c:1179 #3: ffff88807a311958 (&port->lock){-.-.}-{2:2}, at: pty_write+0xea/0x1e0 drivers/tty/pty.c:120 #4: ffffffff8b9703c0 (console_lock){+.+.}-{0:0}, at: vprintk+0x80/0x90 kernel/printk/printk_safe.c:50 stack backtrace: CPU: 0 PID: 22669 Comm: syz-executor.3 Not tainted 5.15.0-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:2146 check_prev_add kernel/locking/lockdep.c:3066 [inline] check_prevs_add kernel/locking/lockdep.c:3189 [inline] validate_chain kernel/locking/lockdep.c:3804 [inline] __lock_acquire+0x2a07/0x54a0 kernel/locking/lockdep.c:5030 lock_acquire kernel/locking/lockdep.c:5640 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5605 console_lock_spinning_enable kernel/printk/printk.c:1781 [inline] console_unlock+0x356/0xb70 kernel/printk/printk.c:2708 vprintk_emit+0x198/0x4f0 kernel/printk/printk.c:2245 vprintk+0x80/0x90 kernel/printk/printk_safe.c:50 _printk+0xba/0xed kernel/printk/printk.c:2266 fail_dump lib/fault-inject.c:45 [inline] should_fail+0x472/0x5a0 lib/fault-inject.c:146 should_failslab+0x5/0x10 mm/slab_common.c:1320 slab_pre_alloc_hook mm/slab.h:494 [inline] slab_alloc mm/slab.c:3306 [inline] __do_kmalloc mm/slab.c:3700 [inline] __kmalloc+0x7b/0x4d0 mm/slab.c:3711 kmalloc include/linux/slab.h:595 [inline] tty_buffer_alloc+0x23f/0x2a0 drivers/tty/tty_buffer.c:177 __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:275 tty_insert_flip_string_fixed_flag+0x93/0x250 drivers/tty/tty_buffer.c:321 tty_insert_flip_string include/linux/tty_flip.h:42 [inline] pty_write+0x11c/0x1e0 drivers/tty/pty.c:122 tty_send_xchar+0x251/0x370 drivers/tty/tty_io.c:1182 n_tty_ioctl_helper+0x179/0x2d0 drivers/tty/tty_ioctl.c:890 n_tty_ioctl+0x4b/0x360 drivers/tty/n_tty.c:2421 tty_ioctl+0xc69/0x1670 drivers/tty/tty_io.c:2814 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: 0033:0x7f6577bc3ae9 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:00007f6575139188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f6577cd6f60 RCX: 00007f6577bc3ae9 RDX: 0000000000000002 RSI: 000000000000540a RDI: 0000000000000004 RBP: 00007f65751391d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffddb62f29f R14: 00007f6575139300 R15: 0000000000022000 CPU: 0 PID: 22669 Comm: syz-executor.3 Not tainted 5.15.0-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 fail_dump lib/fault-inject.c:52 [inline] should_fail.cold+0x5/0xa lib/fault-inject.c:146 should_failslab+0x5/0x10 mm/slab_common.c:1320 slab_pre_alloc_hook mm/slab.h:494 [inline] slab_alloc mm/slab.c:3306 [inline] __do_kmalloc mm/slab.c:3700 [inline] __kmalloc+0x7b/0x4d0 mm/slab.c:3711 kmalloc include/linux/slab.h:595 [inline] tty_buffer_alloc+0x23f/0x2a0 drivers/tty/tty_buffer.c:177 __tty_buffer_request_room+0x156/0x2a0 drivers/tty/tty_buffer.c:275 tty_insert_flip_string_fixed_flag+0x93/0x250 drivers/tty/tty_buffer.c:321 tty_insert_flip_string include/linux/tty_flip.h:42 [inline] pty_write+0x11c/0x1e0 drivers/tty/pty.c:122 tty_send_xchar+0x251/0x370 drivers/tty/tty_io.c:1182 n_tty_ioctl_helper+0x179/0x2d0 drivers/tty/tty_ioctl.c:890 n_tty_ioctl+0x4b/0x360 drivers/tty/n_tty.c:2421 tty_ioctl+0xc69/0x1670 drivers/tty/tty_io.c:2814 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: 0033:0x7f6577bc3ae9 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:00007f6575139188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f6577cd6f60 RCX: 00007f6577bc3ae9 RDX: 0000000000000002 RSI: 000000000000540a RDI: 0000000000000004 RBP: 00007f65751391d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffddb62f29f R14: 00007f6575139300 R15: 0000000000022000