------------[ cut here ]------------
======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc1-syzkaller-00027-g4a4be1ad3a6e #0 Not tainted
------------------------------------------------------
aoe_tx0/1246 is trying to acquire lock:
ffffffff8dabeea0 (console_owner){-.-.}-{0:0}, at: console_trylock_spinning kernel/printk/printk.c:1994 [inline]
ffffffff8dabeea0 (console_owner){-.-.}-{0:0}, at: vprintk_emit kernel/printk/printk.c:2344 [inline]
ffffffff8dabeea0 (console_owner){-.-.}-{0:0}, at: vprintk_emit+0x42d/0x5a0 kernel/printk/printk.c:2300

but task is already holding lock:
ffffffff94dddf78 (&port_lock_key){-.-.}-{2:2}, at: uart_port_lock_irqsave include/linux/serial_core.h:618 [inline]
ffffffff94dddf78 (&port_lock_key){-.-.}-{2:2}, at: uart_write+0x134/0x3e0 drivers/tty/serial/serial_core.c:624

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&port_lock_key){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
       uart_port_lock_irqsave include/linux/serial_core.h:618 [inline]
       serial8250_console_write+0xaa6/0x1090 drivers/tty/serial/8250/8250_port.c:3352
       console_emit_next_record kernel/printk/printk.c:2928 [inline]
       console_flush_all+0x53f/0xd70 kernel/printk/printk.c:2994
       console_unlock+0xae/0x290 kernel/printk/printk.c:3063
       vprintk_emit kernel/printk/printk.c:2345 [inline]
       vprintk_emit+0x11a/0x5a0 kernel/printk/printk.c:2300
       vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45
       _printk+0xc8/0x100 kernel/printk/printk.c:2370
       register_console+0xa88/0x10a0 kernel/printk/printk.c:3596
       univ8250_console_init+0x35/0x50 drivers/tty/serial/8250/8250_core.c:719
       console_init+0xcc/0x680 kernel/printk/printk.c:3742
       start_kernel+0x295/0x4c0 init/main.c:1038
       x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507
       x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488
       common_startup_64+0x13e/0x148

-> #0 (console_owner){-.-.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
       lock_acquire kernel/locking/lockdep.c:5754 [inline]
       lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
       console_trylock_spinning kernel/printk/printk.c:1994 [inline]
       vprintk_emit kernel/printk/printk.c:2344 [inline]
       vprintk_emit+0x442/0x5a0 kernel/printk/printk.c:2300
       vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45
       _printk+0xc8/0x100 kernel/printk/printk.c:2370
       __report_bug lib/bug.c:195 [inline]
       report_bug+0x4ac/0x580 lib/bug.c:219
       handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:239
       exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:260
       asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
       uart_write+0x2bf/0x3e0 drivers/tty/serial/serial_core.c:625
       handle_tx+0x203/0x630 drivers/net/caif/caif_serial.c:236
       __netdev_start_xmit include/linux/netdevice.h:4882 [inline]
       netdev_start_xmit include/linux/netdevice.h:4896 [inline]
       xmit_one net/core/dev.c:3578 [inline]
       dev_hard_start_xmit+0x143/0x790 net/core/dev.c:3594
       __dev_queue_xmit+0x7ba/0x4130 net/core/dev.c:4393
       dev_queue_xmit include/linux/netdevice.h:3095 [inline]
       tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62
       kthread+0x1e7/0x3c0 drivers/block/aoe/aoecmd.c:1229
       kthread+0x2c1/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&port_lock_key);
                               lock(console_owner);
                               lock(&port_lock_key);
  lock(console_owner);

 *** DEADLOCK ***

3 locks held by aoe_tx0/1246:
 #0: ffffffff8dbb1880 (rcu_read_lock_bh){....}-{1:2}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
 #0: ffffffff8dbb1880 (rcu_read_lock_bh){....}-{1:2}, at: rcu_read_lock_bh include/linux/rcupdate.h:833 [inline]
 #0: ffffffff8dbb1880 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x244/0x4130 net/core/dev.c:4318
 #1: ffff8880533bdcd8 (_xmit_NONE#2){+...}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #1: ffff8880533bdcd8 (_xmit_NONE#2){+...}-{2:2}, at: __netif_tx_lock include/linux/netdevice.h:4347 [inline]
 #1: ffff8880533bdcd8 (_xmit_NONE#2){+...}-{2:2}, at: __dev_queue_xmit+0x1af4/0x4130 net/core/dev.c:4389
 #2: ffffffff94dddf78 (&port_lock_key){-.-.}-{2:2}, at: uart_port_lock_irqsave include/linux/serial_core.h:618 [inline]
 #2: ffffffff94dddf78 (&port_lock_key){-.-.}-{2:2}, at: uart_write+0x134/0x3e0 drivers/tty/serial/serial_core.c:624

stack backtrace:
CPU: 1 PID: 1246 Comm: aoe_tx0 Not tainted 6.10.0-rc1-syzkaller-00027-g4a4be1ad3a6e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
 lock_acquire kernel/locking/lockdep.c:5754 [inline]
 lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
 console_trylock_spinning kernel/printk/printk.c:1994 [inline]
 vprintk_emit kernel/printk/printk.c:2344 [inline]
 vprintk_emit+0x442/0x5a0 kernel/printk/printk.c:2300
 vprintk+0x7f/0xa0 kernel/printk/printk_safe.c:45
 _printk+0xc8/0x100 kernel/printk/printk.c:2370
 __report_bug lib/bug.c:195 [inline]
 report_bug+0x4ac/0x580 lib/bug.c:219
 handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:239
 exc_invalid_op+0x17/0x50 arch/x86/kernel/traps.c:260
 asm_exc_invalid_op+0x1a/0x20 arch/x86/include/asm/idtentry.h:621
RIP: 0010:uart_write+0x2bf/0x3e0 drivers/tty/serial/serial_core.c:625
Code: 6b fc e9 4e ff ff ff e8 ff 24 91 fc 90 0f 0b 90 49 c7 c4 d2 ff ff ff e9 39 ff ff ff e8 ea 24 91 fc 45 31 ff e8 e2 24 91 fc 90 <0f> 0b 90 48 85 ed 74 8c e8 d4 24 91 fc 4c 8d a5 08 01 00 00 4c 89
RSP: 0018:ffffc90004eafab8 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffff88801fcc8be8 RCX: ffffffff816c344d
RDX: ffff888023385a00 RSI: ffffffff84fcb00e RDI: ffff88801fcc8f48
RBP: ffffffff94dddf60 R08: 0000000000000001 R09: fffff520009d5f45
R10: 0000000000000003 R11: 0000000000000002 R12: 0000000000000001
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000293
 handle_tx+0x203/0x630 drivers/net/caif/caif_serial.c:236
 __netdev_start_xmit include/linux/netdevice.h:4882 [inline]
 netdev_start_xmit include/linux/netdevice.h:4896 [inline]
 xmit_one net/core/dev.c:3578 [inline]
 dev_hard_start_xmit+0x143/0x790 net/core/dev.c:3594
 __dev_queue_xmit+0x7ba/0x4130 net/core/dev.c:4393
 dev_queue_xmit include/linux/netdevice.h:3095 [inline]
 tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62
 kthread+0x1e7/0x3c0 drivers/block/aoe/aoecmd.c:1229
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
WARNING: CPU: 1 PID: 1246 at drivers/tty/serial/serial_core.c:625 uart_write+0x2bf/0x3e0 drivers/tty/serial/serial_core.c:625
Modules linked in:
CPU: 1 PID: 1246 Comm: aoe_tx0 Not tainted 6.10.0-rc1-syzkaller-00027-g4a4be1ad3a6e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:uart_write+0x2bf/0x3e0 drivers/tty/serial/serial_core.c:625
Code: 6b fc e9 4e ff ff ff e8 ff 24 91 fc 90 0f 0b 90 49 c7 c4 d2 ff ff ff e9 39 ff ff ff e8 ea 24 91 fc 45 31 ff e8 e2 24 91 fc 90 <0f> 0b 90 48 85 ed 74 8c e8 d4 24 91 fc 4c 8d a5 08 01 00 00 4c 89
RSP: 0018:ffffc90004eafab8 EFLAGS: 00010093

RAX: 0000000000000000 RBX: ffff88801fcc8be8 RCX: ffffffff816c344d
RDX: ffff888023385a00 RSI: ffffffff84fcb00e RDI: ffff88801fcc8f48
RBP: ffffffff94dddf60 R08: 0000000000000001 R09: fffff520009d5f45
R10: 0000000000000003 R11: 0000000000000002 R12: 0000000000000001
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000293
FS:  0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020029000 CR3: 0000000023006000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 handle_tx+0x203/0x630 drivers/net/caif/caif_serial.c:236
 __netdev_start_xmit include/linux/netdevice.h:4882 [inline]
 netdev_start_xmit include/linux/netdevice.h:4896 [inline]
 xmit_one net/core/dev.c:3578 [inline]
 dev_hard_start_xmit+0x143/0x790 net/core/dev.c:3594
 __dev_queue_xmit+0x7ba/0x4130 net/core/dev.c:4393
 dev_queue_xmit include/linux/netdevice.h:3095 [inline]
 tx+0xcc/0x190 drivers/block/aoe/aoenet.c:62
 kthread+0x1e7/0x3c0 drivers/block/aoe/aoecmd.c:1229
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>