------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 3 PID: 1143 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Modules linked in:
CPU: 3 UID: 0 PID: 1143 Comm: kworker/u32:7 Not tainted 6.15.0-rc2-syzkaller-00488-g6fea5fabd332 #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
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Code: ff 89 de e8 88 81 eb fc 84 db 0f 85 66 ff ff ff e8 9b 86 eb fc c6 05 df df 9e 0b 01 90 48 c7 c7 40 11 f4 8b e8 f7 14 ab fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 78 86 eb fc 0f b6 1d ba df 9e 0b 31
RSP: 0018:ffffc900006f8be8 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817adff8
RDX: ffff888027692440 RSI: ffffffff817ae005 RDI: 0000000000000001
RBP: ffff8880287d0778 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880287d0778
R13: ffff888035fee400 R14: 0000000000000015 R15: 1ffff110048b400c
FS: 0000000000000000(0000) GS:ffff8880d6cb2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055def07fcd18 CR3: 000000000e180000 CR4: 0000000000352ef0
DR0: 00000000313ccd71 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 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 84 8b 8b e8 68 d3 f5 09 65 66 c7 05 d6 06 2a 12 00 00 e8 d9 3a 46 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:ffffc900006f8f28 EFLAGS: 00000202
RAX: 00000000002de554 RBX: 00000000ffffffff RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8dbef846 RDI: ffffffff8bf46540
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90864917 R11: 0000000000000000 R12: 0000000000000202
R13: 000000000000000a R14: 1ffff920000df1ed R15: ffffed1004ed2488
__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:write_comp_data+0x42/0x90 kernel/kcov.c:246
Code: a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 0f 00 75 60 a9 00 00 f0 00 75 59 8b 82 3c 16 00 00 85 c0 74 4f 8b 82 18 16 00 00 <83> f8 03 75 44 48 8b 82 20 16 00 00 8b 92 1c 16 00 00 48 8b 38 48
RSP: 0018:ffffc90005d6f930 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88806a4415e0 RCX: ffffffff81af38b9
RDX: ffff888027692440 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffed100d4882bd
R13: 0000000000000001 R14: dffffc0000000000 R15: ffff88806a73b040
csd_lock_wait kernel/smp.c:340 [inline]
smp_call_function_many_cond+0x4c9/0x1290 kernel/smp.c:885
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2455 [inline]
text_poke_bp_batch+0x220/0x760 arch/x86/kernel/alternative.c:2665
text_poke_flush arch/x86/kernel/alternative.c:2856 [inline]
text_poke_flush arch/x86/kernel/alternative.c:2853 [inline]
text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2863
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x376/0x550 kernel/jump_label.c:919
static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate mm/kfence/core.c:850 [inline]
toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:842
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
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 84 8b 8b mov $0xffffffff8b8b8420,%rdi
10: e8 68 d3 f5 09 call 0x9f5d37d
15: 65 66 c7 05 d6 06 2a movw $0x0,%gs:0x122a06d6(%rip) # 0x122a06f5
1c: 12 00 00
1f: e8 d9 3a 46 00 call 0x463afd
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