------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 3 PID: 9389 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Modules linked in:
CPU: 3 UID: 0 PID: 9389 Comm: syz.3.960 Not tainted 6.14.0-rc4-syzkaller #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 58 53 f5 fc 84 db 0f 85 66 ff ff ff e8 ab 58 f5 fc c6 05 da 5d 86 0b 01 90 48 c7 c7 40 03 d3 8b e8 37 89 b5 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 88 58 f5 fc 0f b6 1d b5 5d 86 0b 31
RSP: 0018:ffffc90000708d90 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817a1229
RDX: ffff888026f60000 RSI: ffffffff817a1236 RDI: 0000000000000001
RBP: ffff88804df87768 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000004 R12: ffff88804df87768
R13: ffff888041648400 R14: 0000000000000014 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88806a900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3d17f9 CR3: 0000000058a50000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __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
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:mm_counter_file include/linux/mm.h:2635 [inline]
RIP: 0010:mm_counter include/linux/mm.h:2644 [inline]
RIP: 0010:zap_present_folio_ptes mm/memory.c:1521 [inline]
RIP: 0010:zap_present_ptes mm/memory.c:1596 [inline]
RIP: 0010:do_zap_pte_range mm/memory.c:1698 [inline]
RIP: 0010:zap_pte_range mm/memory.c:1742 [inline]
RIP: 0010:zap_pmd_range mm/memory.c:1834 [inline]
RIP: 0010:zap_pud_range mm/memory.c:1863 [inline]
RIP: 0010:zap_p4d_range mm/memory.c:1884 [inline]
RIP: 0010:unmap_page_range+0x1d5f/0x4390 mm/memory.c:1905
Code: e8 16 1b 19 00 4c 89 e8 48 c1 e8 03 42 80 3c 38 00 0f 85 1b 25 00 00 49 8b 55 00 31 ff 48 c1 ea 11 83 e2 01 89 d6 88 54 24 08 <e8> ac f8 b5 ff 0f b6 54 24 08 4c 8b ac 24 88 00 00 00 84 d2 0f 84
RSP: 0018:ffffc90003967848 EFLAGS: 00000246
RAX: 1ffffd40001b66a8 RBX: 0000000000000000 RCX: ffffffff8203e1ba
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 8000000036cd5025 R08: 0000000000000000 R09: fffff940001b66a8
R10: ffffea0000db3547 R11: 0000000000000003 R12: 0000000000000000
R13: ffffea0000db3540 R14: ffff888058b697c0 R15: dffffc0000000000
 unmap_single_vma+0x194/0x2b0 mm/memory.c:1951
 unmap_vmas+0x22f/0x490 mm/memory.c:1995
 exit_mmap+0x1c1/0xba0 mm/mmap.c:1284
 __mmput+0x12a/0x410 kernel/fork.c:1356
 mmput+0x62/0x70 kernel/fork.c:1378
 exit_mm kernel/exit.c:570 [inline]
 do_exit+0x9ba/0x2d70 kernel/exit.c:925
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 __do_sys_exit_group kernel/exit.c:1098 [inline]
 __se_sys_exit_group kernel/exit.c:1096 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096
 x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232
 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: 0033:0x7f4308f8d169
Code: Unable to access opcode bytes at 0x7f4308f8d13f.
RSP: 002b:00007ffca9b6a788 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4308f8d169
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffca9b6a7ec R08: 0000001ea9b6a87f R09: 00000000000927c0
R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000000c9
R13: 00000000000927c0 R14: 00000000000223f0 R15: 00007ffca9b6a840
 </TASK>
----------------
Code disassembly (best guess):
   0:	e8 16 1b 19 00       	call   0x191b1b
   5:	4c 89 e8             	mov    %r13,%rax
   8:	48 c1 e8 03          	shr    $0x3,%rax
   c:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1)
  11:	0f 85 1b 25 00 00    	jne    0x2532
  17:	49 8b 55 00          	mov    0x0(%r13),%rdx
  1b:	31 ff                	xor    %edi,%edi
  1d:	48 c1 ea 11          	shr    $0x11,%rdx
  21:	83 e2 01             	and    $0x1,%edx
  24:	89 d6                	mov    %edx,%esi
  26:	88 54 24 08          	mov    %dl,0x8(%rsp)
* 2a:	e8 ac f8 b5 ff       	call   0xffb5f8db <-- trapping instruction
  2f:	0f b6 54 24 08       	movzbl 0x8(%rsp),%edx
  34:	4c 8b ac 24 88 00 00 	mov    0x88(%rsp),%r13
  3b:	00
  3c:	84 d2                	test   %dl,%dl
  3e:	0f                   	.byte 0xf
  3f:	84                   	.byte 0x84