------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 3 PID: 8066 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Modules linked in:
CPU: 3 UID: 0 PID: 8066 Comm: syz.3.510 Not tainted 6.12.0-rc6-syzkaller-00272-gda4373fbcf00 #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 18 f5 fc fc 84 db 0f 85 66 ff ff ff e8 2b f3 fc fc c6 05 d8 92 b7 0b 01 90 48 c7 c7 c0 60 d1 8b e8 a7 e4 bd fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 08 f3 fc fc 0f b6 1d b3 92 b7 0b 31
RSP: 0018:ffffc90000908d90 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff814e6e79
RDX: ffff88802a6c4880 RSI: ffffffff814e6e86 RDI: 0000000000000001
RBP: ffff888035c93658 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888035c93658
R13: ffff88802352d800 R14: 0000000000000015 R15: 0000000000000000
FS:  00005555905ac500(0000) GS:ffff88806a900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c281e67 CR3: 000000004c5e0000 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:2595 [inline]
 vring_interrupt+0x31b/0x400 drivers/virtio/virtio_ring.c:2570
 __handle_irq_event_percpu+0x229/0x7c0 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:jhash2 include/linux/jhash.h:129 [inline]
RIP: 0010:futex_hash+0x12e/0x200 kernel/futex/core.c:119
Code: 34 08 89 d0 29 d1 c1 c0 10 31 c8 8d 0c 32 89 c3 29 c6 8d 14 08 c1 cb 0d 31 f3 48 89 fe 89 d8 29 d9 48 c1 ee 03 c1 c0 04 01 d3 <31> c8 48 b9 00 00 00 00 00 fc ff df 0f b6 34 0e 48 89 f9 83 e1 07
RSP: 0018:ffffc90004297a30 EFLAGS: 00000a07
RAX: 000000000a6e13aa RBX: 00000000624a773c RCX: 00000000e5c7813c
RDX: 00000000c1a39602 RSI: 1ffff92000852f7e RDI: ffffc90004297bf4
RBP: ffffc90004297be8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000025745600
R13: 00000000deadce8b R14: ffffc90004297ba0 R15: 0000000000000000
 futex_q_lock+0x19/0x70 kernel/futex/core.c:532
 futex_wait_setup+0xfd/0x250 kernel/futex/waitwake.c:622
 __futex_wait+0x267/0x3c0 kernel/futex/waitwake.c:664
 futex_wait+0xe9/0x380 kernel/futex/waitwake.c:697
 do_futex+0x22b/0x350 kernel/futex/syscalls.c:102
 __do_sys_futex kernel/futex/syscalls.c:179 [inline]
 __se_sys_futex kernel/futex/syscalls.c:160 [inline]
 __x64_sys_futex+0x1e1/0x4c0 kernel/futex/syscalls.c:160
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1c04f7e719
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd418ff998 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007ffd418ffac0 RCX: 00007f1c04f7e719
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1c05135f8c
RBP: 00007f1c05135f8c R08: 00007f1c05ce2080 R09: 00007ffd418ffc8f
R10: 00007ffd418ffaa0 R11: 0000000000000246 R12: 000000000002d52b
R13: 00007ffd418ffaa0 R14: 0000000000000032 R15: 000000000002d4f9
 </TASK>
----------------
Code disassembly (best guess):
   0:	34 08                	xor    $0x8,%al
   2:	89 d0                	mov    %edx,%eax
   4:	29 d1                	sub    %edx,%ecx
   6:	c1 c0 10             	rol    $0x10,%eax
   9:	31 c8                	xor    %ecx,%eax
   b:	8d 0c 32             	lea    (%rdx,%rsi,1),%ecx
   e:	89 c3                	mov    %eax,%ebx
  10:	29 c6                	sub    %eax,%esi
  12:	8d 14 08             	lea    (%rax,%rcx,1),%edx
  15:	c1 cb 0d             	ror    $0xd,%ebx
  18:	31 f3                	xor    %esi,%ebx
  1a:	48 89 fe             	mov    %rdi,%rsi
  1d:	89 d8                	mov    %ebx,%eax
  1f:	29 d9                	sub    %ebx,%ecx
  21:	48 c1 ee 03          	shr    $0x3,%rsi
  25:	c1 c0 04             	rol    $0x4,%eax
  28:	01 d3                	add    %edx,%ebx
* 2a:	31 c8                	xor    %ecx,%eax <-- trapping instruction
  2c:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  33:	fc ff df
  36:	0f b6 34 0e          	movzbl (%rsi,%rcx,1),%esi
  3a:	48 89 f9             	mov    %rdi,%rcx
  3d:	83 e1 07             	and    $0x7,%ecx