============================================
WARNING: possible recursive locking detected
5.16.0-rc2-syzkaller #0 Not tainted
--------------------------------------------
kworker/1:2/1156 is trying to acquire lock:
ffffffff9078c430 (&port_lock_key){-.-.}-{2:2}, at: uart_write+0x12c/0x570 drivers/tty/serial/serial_core.c:577
but task is already holding lock:
ffffffff9078c430 (&port_lock_key){-.-.}-{2:2}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1908
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&port_lock_key);
lock(&port_lock_key);
*** DEADLOCK ***
May be due to missing lock nesting notation
7 locks held by kworker/1:2/1156:
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:635 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:662 [inline]
#0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2269
#1: ffffc90005637db0 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2273
#2: ffff88803561a490 (&nsim_dev->port_list_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x5d/0xbc0 drivers/net/netdevsim/dev.c:838
#3: ffff88806decb0e0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
#3: ffff88806decb0e0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:788 [inline]
#3: ffff88806decb0e0 (&nsim_trap_data->trap_lock){+.+.}-{2:2}, at: nsim_dev_trap_report_work+0x1b5/0xbc0 drivers/net/netdevsim/dev.c:843
#4: ffff888070337430 (&i->lock){-.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
#4: ffff888070337430 (&i->lock){-.-.}-{2:2}, at: serial8250_interrupt+0x3a/0x200 drivers/tty/serial/8250/8250_core.c:116
#5: ffffffff9078c430 (&port_lock_key){-.-.}-{2:2}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1908
#6: ffff88807c2ad098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1d/0x80 drivers/tty/tty_ldisc.c:273
stack backtrace:
CPU: 1 PID: 1156 Comm: kworker/1:2 Not tainted 5.16.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events nsim_dev_trap_report_work
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_deadlock_bug kernel/locking/lockdep.c:2956 [inline]
check_deadlock kernel/locking/lockdep.c:2999 [inline]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027
lock_acquire kernel/locking/lockdep.c:5637 [inline]
lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
uart_write+0x12c/0x570 drivers/tty/serial/serial_core.c:577
n_hdlc_send_frames+0x24b/0x490 drivers/tty/n_hdlc.c:290
tty_wakeup+0xe1/0x120 drivers/tty/tty_io.c:534
tty_port_default_wakeup+0x26/0x40 drivers/tty/tty_port.c:51
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
</IRQ>
<TASK>
asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629
RIP: 0010:unwind_next_frame+0xcc9/0x1ce0 arch/x86/kernel/unwind_orc.c:534
Code: 20 e8 3b 5f 8a 00 4c 8b 44 24 20 e9 2c f7 ff ff e8 e3 4d cc ff e9 aa f7 ff ff 48 8b 44 24 60 4c 89 e2 4c 89 f7 48 89 4c 24 30 <4c> 89 44 24 28 48 8d 70 f8 48 89 44 24 20 e8 d4 f1 ff ff 4c 8b 44
RSP: 0018:ffffc900056376a8 EFLAGS: 00000246
RAX: ffffc90005637d20 RBX: 1ffff92000ac6edd RCX: ffffffff8e5c4057
RDX: ffffc900056377c8 RSI: 0000000000000000 RDI: ffffc90005637780
RBP: 0000000000000001 R08: ffffffff8e5c4052 R09: 0000000000000001
R10: fffff52000ac6efb R11: 000000000008808a R12: ffffc900056377c8
R13: ffffc900056377b5 R14: ffffc90005637780 R15: ffffffff8e5c4056
arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38
kasan_set_track+0x21/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xff/0x130 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:1723 [inline]
slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749
slab_free mm/slub.c:3513 [inline]
kfree+0xf6/0x560 mm/slub.c:4561
skb_free_head net/core/skbuff.c:655 [inline]
skb_release_data+0x65a/0x790 net/core/skbuff.c:677
skb_release_all net/core/skbuff.c:742 [inline]
__kfree_skb net/core/skbuff.c:756 [inline]
consume_skb net/core/skbuff.c:912 [inline]
consume_skb+0xc2/0x160 net/core/skbuff.c:906
nsim_dev_trap_report drivers/net/netdevsim/dev.c:818 [inline]
nsim_dev_trap_report_work+0x85d/0xbc0 drivers/net/netdevsim/dev.c:843
process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
----------------
Code disassembly (best guess):
0: 20 e8 and %ch,%al
2: 3b 5f 8a cmp -0x76(%rdi),%ebx
5: 00 4c 8b 44 add %cl,0x44(%rbx,%rcx,4)
9: 24 20 and $0x20,%al
b: e9 2c f7 ff ff jmpq 0xfffff73c
10: e8 e3 4d cc ff callq 0xffcc4df8
15: e9 aa f7 ff ff jmpq 0xfffff7c4
1a: 48 8b 44 24 60 mov 0x60(%rsp),%rax
1f: 4c 89 e2 mov %r12,%rdx
22: 4c 89 f7 mov %r14,%rdi
25: 48 89 4c 24 30 mov %rcx,0x30(%rsp)
* 2a: 4c 89 44 24 28 mov %r8,0x28(%rsp) <-- trapping instruction
2f: 48 8d 70 f8 lea -0x8(%rax),%rsi
33: 48 89 44 24 20 mov %rax,0x20(%rsp)
38: e8 d4 f1 ff ff callq 0xfffff211
3d: 4c rex.WR
3e: 8b .byte 0x8b
3f: 44 rex.R