======================================================
WARNING: possible circular locking dependency detected
5.12.0-rc2-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/9751 is trying to acquire lock:
ffffffff8be83000 (console_owner){....}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1784 [inline]
ffffffff8be83000 (console_owner){....}-{0:0}, at: vprintk_emit+0x2c9/0x560 kernel/printk/printk.c:2097
but task is already holding lock:
ffffffff9011cbb8 (&port->lock){-.-.}-{2:2}, at: tty_port_close_start.part.0+0x28/0x550 drivers/tty/tty_port.c:567
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:159
tty_port_tty_get+0x1f/0x100 drivers/tty/tty_port.c:288
tty_port_default_wakeup+0x11/0x40 drivers/tty/tty_port.c:47
serial8250_tx_chars+0x487/0xa80 drivers/tty/serial/8250/8250_port.c:1832
serial8250_handle_irq.part.0+0x328/0x3d0 drivers/tty/serial/8250/8250_port.c:1919
serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1892 [inline]
serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1935
serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126
__handle_irq_event_percpu+0x303/0x8f0 kernel/irq/handle.c:156
handle_irq_event_percpu kernel/irq/handle.c:196 [inline]
handle_irq_event+0x102/0x290 kernel/irq/handle.c:213
handle_edge_irq+0x25f/0xd00 kernel/irq/chip.c:819
generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
handle_irq arch/x86/kernel/irq.c:231 [inline]
__common_interrupt+0x9e/0x200 arch/x86/kernel/irq.c:250
common_interrupt+0x9f/0xd0 arch/x86/kernel/irq.c:240
asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:623
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:191
spin_unlock_irqrestore include/linux/spinlock.h:409 [inline]
uart_write+0x30d/0x570 drivers/tty/serial/serial_core.c:615
do_output_char+0x5de/0x850 drivers/tty/n_tty.c:443
process_output drivers/tty/n_tty.c:510 [inline]
n_tty_write+0x4c3/0xfd0 drivers/tty/n_tty.c:2365
do_tty_write drivers/tty/tty_io.c:1043 [inline]
file_tty_write.constprop.0+0x526/0x910 drivers/tty/tty_io.c:1133
redirected_tty_write+0xa1/0xc0 drivers/tty/tty_io.c:1140
call_write_iter include/linux/fs.h:1977 [inline]
do_iter_readv_writev+0x46f/0x740 fs/read_write.c:740
do_iter_write+0x188/0x670 fs/read_write.c:866
vfs_writev+0x1aa/0x630 fs/read_write.c:939
do_writev+0x139/0x300 fs/read_write.c:982
do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
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:159
serial8250_console_write+0x8b2/0xae0 drivers/tty/serial/8250/8250_port.c:3292
call_console_drivers kernel/printk/printk.c:1862 [inline]
console_unlock+0x895/0xc80 kernel/printk/printk.c:2576
vprintk_emit+0x1ca/0x560 kernel/printk/printk.c:2098
vprintk_func+0x8d/0x1e0 kernel/printk/printk_safe.c:401
printk+0xba/0xed kernel/printk/printk.c:2146
register_console kernel/printk/printk.c:2927 [inline]
register_console+0x606/0x840 kernel/printk/printk.c:2807
univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:690
console_init+0x3c7/0x596 kernel/printk/printk.c:3027
start_kernel+0x301/0x491 init/main.c:993
secondary_startup_64_no_verify+0xb0/0xbb
-> #0 (console_owner){....}-{0:0}:
check_prev_add kernel/locking/lockdep.c:2936 [inline]
check_prevs_add kernel/locking/lockdep.c:3059 [inline]
validate_chain kernel/locking/lockdep.c:3674 [inline]
__lock_acquire+0x2b14/0x54c0 kernel/locking/lockdep.c:4900
lock_acquire kernel/locking/lockdep.c:5510 [inline]
lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
console_trylock_spinning kernel/printk/printk.c:1805 [inline]
vprintk_emit+0x306/0x560 kernel/printk/printk.c:2097
vprintk_func+0x8d/0x1e0 kernel/printk/printk_safe.c:401
printk+0xba/0xed kernel/printk/printk.c:2146
tty_port_close_start.part.0+0x503/0x550 drivers/tty/tty_port.c:569
tty_port_close_start drivers/tty/tty_port.c:641 [inline]
tty_port_close+0x46/0x170 drivers/tty/tty_port.c:634
tty_release+0x45e/0x1210 drivers/tty/tty_io.c:1779
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:140
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301
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 ***
2 locks held by syz-executor.0/9751:
#0: ffff88802550e1c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_lock+0xbd/0x120 drivers/tty/tty_mutex.c:19
#1: ffffffff9011cbb8 (&port->lock){-.-.}-{2:2}, at: tty_port_close_start.part.0+0x28/0x550 drivers/tty/tty_port.c:567
stack backtrace:
CPU: 1 PID: 9751 Comm: syz-executor.0 Not tainted 5.12.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2127
check_prev_add kernel/locking/lockdep.c:2936 [inline]
check_prevs_add kernel/locking/lockdep.c:3059 [inline]
validate_chain kernel/locking/lockdep.c:3674 [inline]
__lock_acquire+0x2b14/0x54c0 kernel/locking/lockdep.c:4900
lock_acquire kernel/locking/lockdep.c:5510 [inline]
lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475
console_trylock_spinning kernel/printk/printk.c:1805 [inline]
vprintk_emit+0x306/0x560 kernel/printk/printk.c:2097
vprintk_func+0x8d/0x1e0 kernel/printk/printk_safe.c:401
printk+0xba/0xed kernel/printk/printk.c:2146
tty_port_close_start.part.0+0x503/0x550 drivers/tty/tty_port.c:569
tty_port_close_start drivers/tty/tty_port.c:641 [inline]
tty_port_close+0x46/0x170 drivers/tty/tty_port.c:634
tty_release+0x45e/0x1210 drivers/tty/tty_io.c:1779
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:140
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:301
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x41927b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007ffee3cc55e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 000000000041927b
RDX: 0000000000570148 RSI: 0000000000000081 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000570148
R13: 00007ffee3cc5700 R14: 000000000056bf60 R15: 0000000000028310