------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 1309 at lib/refcount.c:25 refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 1309 Comm: kworker/0:1H Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_highpri snd_vmidi_output_work
RIP: 0010:refcount_warn_saturate+0xff/0x1a0 lib/refcount.c:25
Code: 09 01 48 c7 c7 40 6b 59 8a e8 dd 27 bb 05 0f 0b eb e0 e8 04 42 9c fd c6 05 ae 8f 79 09 01 48 c7 c7 80 6a 59 8a e8 c1 27 bb 05 <0f> 0b eb c4 e8 e8 41 9c fd c6 05 93 8f 79 09 01 48 c7 c7 e0 6a 59
RSP: 0018:ffffc900000076a8 EFLAGS: 00010246
RAX: 2775df07e78c2f00 RBX: 0000000000000002 RCX: ffff888021f7bb80
RDX: 0000000000000100 RSI: 0000000000000101 RDI: 0000000000000000
RBP: ffffc90000007808 R08: dffffc0000000000 R09: fffff52000000e39
R10: fffff52000000e39 R11: 1ffff92000000e38 R12: ffff88801ad99a80
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002000 CR3: 000000004f923000 CR4: 00000000003506f0
DR0: 00000000000000f8 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __refcount_add include/linux/refcount.h:-1 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 get_net include/net/net_namespace.h:252 [inline]
 tipc_aead_encrypt net/tipc/crypto.c:832 [inline]
 tipc_crypto_xmit+0x1949/0x2560 net/tipc/crypto.c:1772
 tipc_crypto_clone_msg+0x91/0x160 net/tipc/crypto.c:1667
 tipc_crypto_xmit+0x1ac5/0x2560 net/tipc/crypto.c:1728
 tipc_bearer_xmit_skb+0x228/0x3c0 net/tipc/bearer.c:574
 tipc_disc_timeout+0x568/0x6b0 net/tipc/discover.c:338
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 3e 14 d3 f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 06 94 a6 f7 65 8b 05 a7 a3 57 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90005127a40 EFLAGS: 00000206
RAX: 2775df07e78c2f00 RBX: 0000000000000a06 RCX: 2775df07e78c2f00
RDX: dffffc0000000000 RSI: ffffffff8a0b11c0 RDI: 0000000000000001
RBP: ffffc90005127ad0 R08: dffffc0000000000 R09: fffffbfff1ff3641
R10: fffffbfff1ff3641 R11: 1ffffffff1ff3640 R12: dffffc0000000000
R13: 0000000000000001 R14: ffff88805f736050 R15: 1ffff92000a24f48
 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline]
 snd_rawmidi_transmit+0x349/0x400 sound/core/rawmidi.c:1417
 snd_vmidi_output_work+0x1a0/0x400 sound/core/seq/seq_virmidi.c:151
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
----------------
Code disassembly (best guess):
   0:	74 05                	je     0x7
   2:	e8 3e 14 d3 f7       	call   0xf7d31445
   7:	48 c7 44 24 20 00 00 	movq   $0x0,0x20(%rsp)
   e:	00 00
  10:	9c                   	pushf
  11:	8f 44 24 20          	pop    0x20(%rsp)
  15:	f6 44 24 21 02       	testb  $0x2,0x21(%rsp)
  1a:	75 4b                	jne    0x67
  1c:	f7 c3 00 02 00 00    	test   $0x200,%ebx
  22:	74 01                	je     0x25
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 06 94 a6 f7       	call   0xf7a69435 <-- trapping instruction
  2f:	65 8b 05 a7 a3 57 76 	mov    %gs:0x7657a3a7(%rip),%eax        # 0x7657a3dd
  36:	85 c0                	test   %eax,%eax
  38:	74 3c                	je     0x76
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7
  3c:	04 24                	add    $0x24,%al
  3e:	0e                   	(bad)
  3f:	36                   	ss