------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 3 PID: 10647 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Modules linked in: CPU: 3 UID: 0 PID: 10647 Comm: syz.0.1293 Not tainted 6.14.0-rc3-syzkaller-00096-ge9a8cac0bf89 #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 98 4e f5 fc 84 db 0f 85 66 ff ff ff e8 eb 53 f5 fc c6 05 a7 54 86 0b 01 90 48 c7 c7 40 02 d3 8b e8 87 85 b5 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 c8 53 f5 fc 0f b6 1d 82 54 86 0b 31 RSP: 0018:ffffc90000708d90 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817a1229 RDX: ffff888028092440 RSI: ffffffff817a1236 RDI: 0000000000000001 RBP: ffff888032087a98 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888032087a98 R13: ffff88805f01d400 R14: 0000000000000015 R15: 0000000000000000 FS: 000055557bbe8500(0000) GS:ffff88806a900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0faadf6d58 CR3: 0000000023e28000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 a6 f9 3c f6 48 89 df e8 fe 78 3d f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 85 4f 2e f6 65 8b 05 a6 33 aa 74 85 c0 74 16 5b RSP: 0018:ffffc90003707b88 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffff888031be2e50 RCX: 1ffffffff20c4191 RDX: 0000000000000000 RSI: ffffffff8b6ceca0 RDI: ffffffff8bd35540 RBP: 0000000000000206 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90625017 R11: ffffffff818ba9ce R12: ffff888031be2454 R13: ffff888031be2e50 R14: ffff888031be2440 R15: ffffc90003707be8 class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:551 [inline] try_to_wake_up+0x949/0x1490 kernel/sched/core.c:4214 wake_up_process kernel/sched/core.c:4463 [inline] wake_up_q+0x9c/0x160 kernel/sched/core.c:1075 futex_wake+0x43e/0x4e0 kernel/futex/waitwake.c:199 do_futex+0x1e5/0x350 kernel/futex/syscalls.c:107 __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: 0033:0x7f0facf8d0a9 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:00007fffb5af67e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f0fad1a6088 RCX: 00007f0facf8d0a9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f0fad1a6088 RBP: 0000000000000001 R08: 0000000000000000 R09: 00000008b5af6adf R10: 00007f0fad1a5fa0 R11: 0000000000000246 R12: 00007f0fad1a608c R13: 00007f0fad1a6080 R14: 0000000000000fd1 R15: 0000000000000005 ---------------- Code disassembly (best guess): 0: f5 cmc 1: 53 push %rbx 2: 48 8b 74 24 10 mov 0x10(%rsp),%rsi 7: 48 89 fb mov %rdi,%rbx a: 48 83 c7 18 add $0x18,%rdi e: e8 a6 f9 3c f6 call 0xf63cf9b9 13: 48 89 df mov %rbx,%rdi 16: e8 fe 78 3d f6 call 0xf63d7919 1b: f7 c5 00 02 00 00 test $0x200,%ebp 21: 75 23 jne 0x46 23: 9c pushf 24: 58 pop %rax 25: f6 c4 02 test $0x2,%ah 28: 75 37 jne 0x61 * 2a: bf 01 00 00 00 mov $0x1,%edi <-- trapping instruction 2f: e8 85 4f 2e f6 call 0xf62e4fb9 34: 65 8b 05 a6 33 aa 74 mov %gs:0x74aa33a6(%rip),%eax # 0x74aa33e1 3b: 85 c0 test %eax,%eax 3d: 74 16 je 0x55 3f: 5b pop %rbx