------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 13240 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Modules linked in:
CPU: 0 UID: 0 PID: 13240 Comm: syz.3.1575 Not tainted 6.14.0-rc4-syzkaller-00015-g2a1944bff549 #0
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 d8 6b f7 fc 84 db 0f 85 66 ff ff ff e8 2b 71 f7 fc c6 05 d2 94 88 0b 01 90 48 c7 c7 c0 f3 d2 8b e8 57 a2 b7 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 08 71 f7 fc 0f b6 1d ad 94 88 0b 31
RSP: 0018:ffffc90000007d90 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817a1229
RDX: ffff8880254e2440 RSI: ffffffff817a1236 RDI: 0000000000000001
RBP: ffff888069b13cb8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff888069b13cb8
R13: ffff88804e627000 R14: 0000000000000015 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88802b400000(0063) knlGS:00000000f5085b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000080030000 CR3: 00000000712c4000 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:275 [inline]
 __refcount_dec_and_test include/linux/refcount.h:307 [inline]
 refcount_dec_and_test include/linux/refcount.h:325 [inline]
 p9_req_put+0x1ec/0x250 net/9p/client.c:404
 req_done+0x1e7/0x2f0 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:247 [inline]
 call_irq_handler arch/x86/kernel/irq.c:259 [inline]
 __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:285
 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:278
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:__might_sleep+0x18/0x170 kernel/sched/core.c:8683
Code: 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 41 54 65 4c 8b 25 e8 dd 7b 7e <55> 89 f5 53 48 89 fb 49 8d 7c 24 18 48 83 ec 10 48 89 fa 48 c1 ea
RSP: 0018:ffffc90002ec7680 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffff888027fbaea8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000232 RDI: ffffffff8b6cd720
RBP: ffffc90002ec77d0 R08: ffffffff89fa8ae7 R09: 0000000000000000
R10: ffffc90002ec77f0 R11: 0000000000000000 R12: ffff8880254e2440
R13: 0000000000000002 R14: 0000000000000000 R15: ffffc90002ec7710
 __mutex_lock_common kernel/locking/mutex.c:562 [inline]
 __mutex_lock+0x108/0xb10 kernel/locking/mutex.c:730
 __unix_dgram_recvmsg+0x267/0xe50 net/unix/af_unix.c:2426
 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2531
 sock_recvmsg_nosec net/socket.c:1023 [inline]
 ____sys_recvmsg+0x5f8/0x6b0 net/socket.c:2791
 ___sys_recvmsg+0x115/0x1a0 net/socket.c:2835
 do_recvmmsg+0x55d/0x740 net/socket.c:2922
 __sys_recvmmsg+0x21e/0x280 net/socket.c:3004
 __do_compat_sys_recvmmsg_time32 net/compat.c:418 [inline]
 __se_compat_sys_recvmmsg_time32 net/compat.c:414 [inline]
 __ia32_compat_sys_recvmmsg_time32+0xc4/0x160 net/compat.c:414
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f81579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f508555c EFLAGS: 00000296 ORIG_RAX: 0000000000000151
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000800000c0
RDX: 0000000000010106 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 90 90 90 90 90    	add    %dl,-0x6f6f6f70(%rax)
   6:	90                   	nop
   7:	90                   	nop
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	f3 0f 1e fa          	endbr64
  16:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1d:	fc ff df
  20:	41 54                	push   %r12
  22:	65 4c 8b 25 e8 dd 7b 	mov    %gs:0x7e7bdde8(%rip),%r12        # 0x7e7bde12
  29:	7e
* 2a:	55                   	push   %rbp <-- trapping instruction
  2b:	89 f5                	mov    %esi,%ebp
  2d:	53                   	push   %rbx
  2e:	48 89 fb             	mov    %rdi,%rbx
  31:	49 8d 7c 24 18       	lea    0x18(%r12),%rdi
  36:	48 83 ec 10          	sub    $0x10,%rsp
  3a:	48 89 fa             	mov    %rdi,%rdx
  3d:	48                   	rex.W
  3e:	c1                   	.byte 0xc1
  3f:	ea                   	(bad)