------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 3 PID: 0 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Modules linked in: CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted 6.14.0-rc5-syzkaller-00105-gf315296c92fd #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 a8 40 f5 fc 84 db 0f 85 66 ff ff ff e8 fb 45 f5 fc c6 05 ef 42 86 0b 01 90 48 c7 c7 e0 14 d3 8b e8 87 74 b5 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 d8 45 f5 fc 0f b6 1d ca 42 86 0b 31 RSP: 0018:ffffc90000708d90 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817a2229 RDX: ffff88801daaa440 RSI: ffffffff817a2236 RDI: 0000000000000001 RBP: ffff888035692338 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888035692338 R13: ffff888021710c00 R14: 0000000000000015 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88806a900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb2aea57f98 CR3: 000000000df80000 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:249 [inline] call_irq_handler arch/x86/kernel/irq.c:261 [inline] __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:287 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:280 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:default_idle+0xf/0x20 arch/x86/kernel/process.c:744 Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 53 30 0f 00 fb f4 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 RSP: 0018:ffffc900001a7e08 EFLAGS: 00000206 RAX: 0000000000054af9 RBX: 0000000000000003 RCX: ffffffff8b576469 RDX: 0000000000000000 RSI: ffffffff8b6cfb00 RDI: ffffffff8bd367e0 RBP: ffffed1003b55488 R08: 0000000000000001 R09: ffffed100d526f85 R10: ffff88806a937c2b R11: 0000000000000000 R12: 0000000000000003 R13: ffff88801daaa440 R14: ffffffff90626010 R15: 0000000000000000 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x329/0x3f0 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x222/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148 ---------------- Code disassembly (best guess): 0: 4c 01 c7 add %r8,%rdi 3: 4c 29 c2 sub %r8,%rdx 6: e9 72 ff ff ff jmp 0xffffff7d b: 90 nop c: 90 nop d: 90 nop e: 90 nop 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: f3 0f 1e fa endbr64 1f: eb 07 jmp 0x28 21: 0f 00 2d 53 30 0f 00 verw 0xf3053(%rip) # 0xf307b 28: fb sti 29: f4 hlt * 2a: fa cli <-- trapping instruction 2b: c3 ret 2c: cc int3 2d: cc int3 2e: cc int3 2f: cc int3 30: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1) 37: 00 00 00 00 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop