------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 3 PID: 8240 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Modules linked in:
CPU: 3 UID: 0 PID: 8240 Comm: syz.3.680 Not tainted 6.13.0-rc6-syzkaller-00130-g2144da25584e #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 48 d9 f9 fc 84 db 0f 85 66 ff ff ff e8 9b de f9 fc c6 05 ea b9 a7 0b 01 90 48 c7 c7 a0 9a d1 8b e8 57 15 ba fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 78 de f9 fc 0f b6 1d c5 b9 a7 0b 31
RSP: 0018:ffffc90000708d90 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff815a5139
RDX: ffff888023398000 RSI: ffffffff815a5146 RDI: 0000000000000001
RBP: ffff888030148008 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000002 R12: ffff888030148008
R13: ffff88803475ec00 R14: 0000000000000015 R15: 0000000000000000
FS:  000055558087b500(0000) GS:ffff88806a900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f061199dd58 CR3: 0000000057fc0000 CR4: 0000000000352ef0
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:mas_empty_area_rev+0x11/0x2570 lib/maple_tree.c:5141
Code: 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 49 89 ff 41 56 41 55 41 54 55 53 <48> 81 ec a0 00 00 00 48 89 94 24 90 00 00 00 48 89 34 24 48 89 4c
RSP: 0018:ffffc90006d0fa08 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffc90006d0fbd8 RCX: 0000000000021000
RDX: 00007f06119e5fff RSI: 0000000000010000 RDI: ffffc90006d0fab8
RBP: 00007f06119e6000 R08: 0000000000000006 R09: 0000000000021000
R10: 0000000000021000 R11: 0000000000000000 R12: ffffc90006d0fab8
R13: 0000000000021000 R14: dffffc0000000000 R15: ffffc90006d0fab8
 vma_iter_area_highest mm/vma.h:340 [inline]
 unmapped_area_topdown mm/mmap.c:668 [inline]
 vm_unmapped_area+0x33f/0xb90 mm/mmap.c:719
 arch_get_unmapped_area_topdown+0x4ef/0x860 arch/x86/kernel/sys_x86_64.c:227
 mm_get_unmapped_area_vmflags+0xcc/0xe0 mm/mmap.c:857
 __get_unmapped_area+0x386/0x440 mm/mmap.c:902
 do_mmap+0x312/0x1050 mm/mmap.c:354
 vm_mmap_pgoff+0x1ba/0x360 mm/util.c:575
 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:546
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
 __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
 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: 0033:0x7f0610b85d63
Code: f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 f7 c1 ff 0f 00 00 75 14 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 25 c3 0f 1f 40 00 48 c7 c0 a8 ff ff ff 64 c7
RSP: 002b:00007ffeea53e638 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f060f1f76c0 RCX: 00007f0610b85d63
RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000020022 R11: 0000000000000246 R12: 00007ffeea53e790
R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	2e 0f 1f 84 00 00 00 	cs nopl 0x0(%rax,%rax,1)
   7:	00 00
   9:	90                   	nop
   a:	90                   	nop
   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:	f3 0f 1e fa          	endbr64
  1d:	41 57                	push   %r15
  1f:	49 89 ff             	mov    %rdi,%r15
  22:	41 56                	push   %r14
  24:	41 55                	push   %r13
  26:	41 54                	push   %r12
  28:	55                   	push   %rbp
  29:	53                   	push   %rbx
* 2a:	48 81 ec a0 00 00 00 	sub    $0xa0,%rsp <-- trapping instruction
  31:	48 89 94 24 90 00 00 	mov    %rdx,0x90(%rsp)
  38:	00
  39:	48 89 34 24          	mov    %rsi,(%rsp)
  3d:	48                   	rex.W
  3e:	89                   	.byte 0x89
  3f:	4c                   	rex.WR