======================================================
WARNING: possible circular locking dependency detected
5.12.0-rc7-next-20210412-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor375/10920 is trying to acquire lock:
ffffffff8be851c0 (console_owner){....}-{0:0}, at: console_unlock+0x2e6/0xc40 kernel/printk/printk.c:2619
but task is already holding lock:
ffffffff9015e4f8 (&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:1826
serial8250_handle_irq.part.0+0x328/0x3d0 drivers/tty/serial/8250/8250_port.c:1913
serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1886 [inline]
serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1929
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+0x9d/0x210 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
native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline]
acpi_idle_do_entry+0x1c9/0x250 drivers/acpi/processor_idle.c:513
acpi_idle_enter+0x361/0x500 drivers/acpi/processor_idle.c:648
cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:237
cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351
call_cpuidle kernel/sched/idle.c:158 [inline]
cpuidle_idle_call kernel/sched/idle.c:239 [inline]
do_idle+0x3e8/0x590 kernel/sched/idle.c:306
cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
start_secondary+0x274/0x350 arch/x86/kernel/smpboot.c:272
secondary_startup_64_no_verify+0xb0/0xbb
-> #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:3286
call_console_drivers kernel/printk/printk.c:1938 [inline]
console_unlock+0x859/0xc40 kernel/printk/printk.c:2643
vprintk_emit+0x1ca/0x560 kernel/printk/printk.c:2174
vprintk+0x8d/0x260 kernel/printk/printk_safe.c:392
printk+0xba/0xed kernel/printk/printk.c:2216
register_console kernel/printk/printk.c:2991 [inline]
register_console+0x55f/0x780 kernel/printk/printk.c:2870
univ8250_console_init+0x3a/0x46 drivers/tty/serial/8250/8250_core.c:690
console_init+0x3c7/0x596 kernel/printk/printk.c:3091
start_kernel+0x306/0x496 init/main.c:1016
secondary_startup_64_no_verify+0xb0/0xbb
-> #0 (console_owner){....}-{0:0}:
check_prev_add kernel/locking/lockdep.c:2938 [inline]
check_prevs_add kernel/locking/lockdep.c:3061 [inline]
validate_chain kernel/locking/lockdep.c:3676 [inline]
__lock_acquire+0x2a17/0x5230 kernel/locking/lockdep.c:4902
lock_acquire kernel/locking/lockdep.c:5512 [inline]
lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5477
console_lock_spinning_enable kernel/printk/printk.c:1790 [inline]
console_unlock+0x359/0xc40 kernel/printk/printk.c:2640
vprintk_emit+0x1ca/0x560 kernel/printk/printk.c:2174
vprintk+0x8d/0x260 kernel/printk/printk_safe.c:392
printk+0xba/0xed kernel/printk/printk.c:2216
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:1778
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
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+0x272/0x280 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:57
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 ***
3 locks held by syz-executor375/10920:
#0: ffff888013e631c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_lock+0xbd/0x120 drivers/tty/tty_mutex.c:19
#1: ffffffff9015e4f8 (&port->lock){-.-.}-{2:2}, at: tty_port_close_start.part.0+0x28/0x550 drivers/tty/tty_port.c:567
#2: ffffffff8bf655a0 (console_lock){+.+.}-{0:0}, at: vprintk+0x8d/0x260 kernel/printk/printk_safe.c:392
stack backtrace:
CPU: 0 PID: 10920 Comm: syz-executor375 Not tainted 5.12.0-rc7-next-20210412-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:2129
check_prev_add kernel/locking/lockdep.c:2938 [inline]
check_prevs_add kernel/locking/lockdep.c:3061 [inline]
validate_chain kernel/locking/lockdep.c:3676 [inline]
__lock_acquire+0x2a17/0x5230 kernel/locking/lockdep.c:4902
lock_acquire kernel/locking/lockdep.c:5512 [inline]
lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5477
console_lock_spinning_enable kernel/printk/printk.c:1790 [inline]
console_unlock+0x359/0xc40 kernel/printk/printk.c:2640
vprintk_emit+0x1ca/0x560 kernel/printk/printk.c:2174
vprintk+0x8d/0x260 kernel/printk/printk_safe.c:392
printk+0xba/0xed kernel/printk/printk.c:2216
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:1778
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
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+0x272/0x280 kernel/entry/common.c:208
__syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:57
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x409aeb
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 03 fd 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 41 fd ff ff 8b 44
RSP: 002b:00007ffd49bbd7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000409aeb
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000032 R08: 0000000000000000 R09: 000000000049e190
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000004cf4dc
R13: 00007ffd49bbd7f0 R14: 00007ffd49bbd810 R15: 00007ffd49bbd880