------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 0 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Modules linked in:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc4-syzkaller-00208-g00b827f0cffa #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Code: ff 89 de e8 58 18 ed fc 84 db 0f 85 66 ff ff ff e8 6b 1d ed fc c6 05 2f f9 9f 0b 01 90 48 c7 c7 60 17 f4 8b e8 67 fe ac fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 48 1d ed fc 0f b6 1d 0a f9 9f 0b 31
RSP: 0018:ffffc90000007d90 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817a8f78
RDX: ffffffff8e097740 RSI: ffffffff817a8f85 RDI: 0000000000000001
RBP: ffff888071c10ff8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888071c10ff8
R13: ffff88806ab4c800 R14: 0000000000000015 R15: 1ffff11004b7d00c
FS:  0000000000000000(0000) GS:ffff8880977ec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000c31211b CR3: 000000005ac4c000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __refcount_sub_and_test include/linux/refcount.h:400 [inline]
 __refcount_dec_and_test include/linux/refcount.h:432 [inline]
 refcount_dec_and_test include/linux/refcount.h:450 [inline]
 p9_req_put+0x1ec/0x250 net/9p/client.c:404
 req_done+0x1dc/0x2e0 net/9p/trans_virtio.c:147
 vring_interrupt drivers/virtio/virtio_ring.c:2715 [inline]
 vring_interrupt+0x31b/0x400 drivers/virtio/virtio_ring.c:2690
 __handle_irq_event_percpu+0x229/0x7d0 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
 handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:210
 handle_edge_irq+0x263/0xd10 kernel/irq/chip.c:831
 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
 handle_irq arch/x86/kernel/irq.c:254 [inline]
 call_irq_handler arch/x86/kernel/irq.c:266 [inline]
 __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:292
 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:285
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81
Code: 36 65 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 43 b9 20 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007e10 EFLAGS: 00000282
RAX: 0000000000929ac1 RBX: 0000000000000000 RCX: ffffffff8b6933e9
RDX: 0000000000000000 RSI: ffffffff8dbdb22b RDI: ffffffff8bf46b60
RBP: fffffbfff1c12ee8 R08: 0000000000000001 R09: ffffed10056465bd
R10: ffff88802b232deb R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff8e097740 R14: ffffffff90851d10 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:748
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
 rest_init+0x16b/0x2b0 init/main.c:743
 start_kernel+0x3e9/0x4d0 init/main.c:1099
 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:513
 x86_64_start_kernel+0xb0/0xc0 arch/x86/kernel/head64.c:494
 common_startup_64+0x13e/0x148
 </TASK>
----------------
Code disassembly (best guess):
   0:	36 65 02 c3          	ss gs add %bl,%al
   4:	cc                   	int3
   5:	cc                   	int3
   6:	cc                   	int3
   7:	cc                   	int3
   8:	0f 1f 00             	nopl   (%rax)
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	f3 0f 1e fa          	endbr64
  1f:	eb 07                	jmp    0x28
  21:	0f 00 2d 43 b9 20 00 	verw   0x20b943(%rip)        # 0x20b96b
  28:	fb                   	sti
  29:	f4                   	hlt
* 2a:	c3                   	ret <-- trapping instruction
  2b:	cc                   	int3
  2c:	cc                   	int3
  2d:	cc                   	int3
  2e:	cc                   	int3
  2f:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
  36:	00 00 00
  39:	66 90                	xchg   %ax,%ax
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop
  3f:	90                   	nop