------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 5650 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Modules linked in:
CPU: 0 UID: 0 PID: 5650 Comm: dhcpcd Not tainted 6.15.0-rc5-syzkaller #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 38 f5 ec fc 84 db 0f 85 66 ff ff ff e8 4b fa ec fc c6 05 4f db 9f 0b 01 90 48 c7 c7 20 18 f4 8b e8 47 db ac fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 28 fa ec fc 0f b6 1d 2a db 9f 0b 31
RSP: 0018:ffffc90000007be8 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817a8f78
RDX: ffff888021f6a440 RSI: ffffffff817a8f85 RDI: 0000000000000001
RBP: ffff88804daca998 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88804daca998
R13: ffff8880516dc000 R14: 0000000000000015 R15: 1ffff11003e6400c
FS: 00007f773f242740(0000) GS:ffff8880977ec000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000056b814c0 CR3: 000000004b9fa000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 00000000e08e000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__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+0x61/0xe0 arch/x86/kernel/irq.c:285
asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:handle_softirqs+0x1dd/0x8e0 kernel/softirq.c:565
Code: 88 6c 24 26 4c 89 7c 24 18 48 c7 c7 20 82 8b 8b e8 c8 d6 ec 09 65 66 c7 05 66 ba 26 12 00 00 e8 a9 e9 45 00 fb bb ff ff ff ff <49> c7 c7 c0 c0 00 8e 41 0f bc dc 83 c3 01 0f 85 a4 00 00 00 e9 b1
RSP: 0018:ffffc90000007f28 EFLAGS: 00000216
RAX: 0000000000529090 RBX: 00000000ffffffff RCX: ffffffff81c26e7f
RDX: 0000000000000000 RSI: ffffffff8dbdb661 RDI: ffffffff8bf46c20
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90852317 R11: 0000000000000000 R12: 0000000000000202
R13: 000000000000000a R14: 1ffff92000000fed R15: ffffed10043ed488
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:preempt_schedule_irq+0x4c/0x90 kernel/sched/core.c:7090
Code: df 55 65 48 8b 2d 0c c3 38 08 53 48 89 eb 48 c1 eb 03 48 01 c3 bf 01 00 00 00 e8 9f 3c 1e f6 e8 5a f2 57 f6 fb bf 01 00 00 00 af 99 ff ff 9c 58 fa f6 c4 02 75 1e bf 01 00 00 00 e8 ed e6 1d
RSP: 0018:ffffc9000349f828 EFLAGS: 00000206
RAX: 000000000052908d RBX: ffffed10043ed488 RCX: ffffffff81c26e7f
RDX: 0000000000000000 RSI: ffffffff8dbdb661 RDI: 0000000000000001
RBP: ffff888021f6a440 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90852317 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
irqentry_exit+0x36/0x90 kernel/entry/common.c:354
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: e9 4d c0 59 00 be 03 00 00 00 5b e9 92 04 13 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 34 24 <65> 48 8b 15 38 93 e8 11 65 8b 05 49 93 e8 11 a9 00 01 ff 00 74 1d
RSP: 0018:ffffc9000349f8f0 EFLAGS: 00000246
RAX: ffffc9000349f9c8 RBX: ffffc9000349fd30 RCX: 0000000000000000
RDX: ffffc9000349f9e4 RSI: ffffffff84804dc8 RDI: ffff8880425c5400
RBP: ffff8880425c5400 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc9000349f9c8 R11: 0000000000000000 R12: 0000000000000000
R13: ffffc9000349f9e4 R14: ffff8880425c5400 R15: ffff8880498608c0
arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline]
security_socket_getpeersec_dgram+0x18/0x290 security/security.c:4824
unix_get_peersec_dgram include/net/scm.h:62 [inline]
scm_send include/net/scm.h:99 [inline]
unix_dgram_sendmsg+0x108/0x1910 net/unix/af_unix.c:1961
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg net/socket.c:727 [inline]
sock_write_iter+0x4fc/0x5b0 net/socket.c:1131
do_iter_readv_writev+0x654/0x950 fs/read_write.c:825
vfs_writev+0x353/0xdc0 fs/read_write.c:1055
do_writev+0x295/0x330 fs/read_write.c:1101
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f773f310e03
Code: 89 c7 48 89 44 24 08 e8 6a f2 f9 ff 48 8b 44 24 08 48 83 c4 28 c3 c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 14 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 6d 48 8b 15 f6 5f 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffce7091218 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f773f2426c0 RCX: 00007f773f310e03
RDX: 0000000000000002 RSI: 00007ffce7091260 RDI: 000000000000000b
RBP: 00007ffce70b15c8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffce7091288
R13: 00007ffce70a1408 R14: 00007ffce7091288 R15: 0000000000000000
----------------
Code disassembly (best guess):
0: 88 6c 24 26 mov %ch,0x26(%rsp)
4: 4c 89 7c 24 18 mov %r15,0x18(%rsp)
9: 48 c7 c7 20 82 8b 8b mov $0xffffffff8b8b8220,%rdi
10: e8 c8 d6 ec 09 call 0x9ecd6dd
15: 65 66 c7 05 66 ba 26 movw $0x0,%gs:0x1226ba66(%rip) # 0x1226ba85
1c: 12 00 00
1f: e8 a9 e9 45 00 call 0x45e9cd
24: fb sti
25: bb ff ff ff ff mov $0xffffffff,%ebx
* 2a: 49 c7 c7 c0 c0 00 8e mov $0xffffffff8e00c0c0,%r15 <-- trapping instruction
31: 41 0f bc dc bsf %r12d,%ebx
35: 83 c3 01 add $0x1,%ebx
38: 0f 85 a4 00 00 00 jne 0xe2
3e: e9 .byte 0xe9
3f: b1 .byte 0xb1