------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 45 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Modules linked in:
CPU: 0 UID: 0 PID: 45 Comm: kworker/u32:2 Not tainted 6.14.0-rc1-syzkaller-00028-g5c8c229261f1 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: bat_events batadv_nc_worker
RIP: 0010:refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Code: ff 89 de e8 98 2d fc fc 84 db 0f 85 66 ff ff ff e8 eb 32 fc fc c6 05 8f ad 8b 0b 01 90 48 c7 c7 60 87 d2 8b e8 07 0d bd fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 c8 32 fc fc 0f b6 1d 6a ad 8b 0b 31
RSP: 0018:ffffc90000007d90 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8179c889
RDX: ffff88801ede8000 RSI: ffffffff8179c896 RDI: 0000000000000001
RBP: ffff888067996998 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000003 R12: ffff888067996998
R13: ffff8880008cb000 R14: 0000000000000015 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88802b400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000f741abc4 CR3: 0000000062624000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__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
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:__sanitizer_cov_trace_cmp4+0xa/0x20 kernel/kcov.c:288
Code: 00 00 00 e9 18 ff ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 0c 24 89 f2 <89> fe bf 04 00 00 00 e9 ea fe ff ff 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc900006c7b28 EFLAGS: 00000246
RAX: ffff88804c5d3200 RBX: 0000000000000400 RCX: ffffffff8b15579c
RDX: 0000000000000400 RSI: 0000000000000400 RDI: 00000000000002e0
RBP: 00000000000002e0 R08: 0000000000000000 R09: fffffbfff20bfb02
R10: ffffffff905fd817 R11: 0000000000000002 R12: 0000000000000001
R13: ffff88801b0b0000 R14: 0000000000000000 R15: dffffc0000000000
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:405 [inline]
batadv_nc_worker+0x8bc/0x1060 net/batman-adv/network-coding.c:719
process_one_work+0x958/0x1b30 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3317 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
kthread+0x3af/0x750 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 00 00 add %al,(%rax)
2: e9 18 ff ff ff jmp 0xffffff1f
7: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
e: 00
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: 90 nop
1c: 90 nop
1d: 90 nop
1e: 90 nop
1f: f3 0f 1e fa endbr64
23: 48 8b 0c 24 mov (%rsp),%rcx
27: 89 f2 mov %esi,%edx
* 29: 89 fe mov %edi,%esi <-- trapping instruction
2b: bf 04 00 00 00 mov $0x4,%edi
30: e9 ea fe ff ff jmp 0xffffff1f
35: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1)
3c: 00 00 00