------------[ cut here ]------------
WARNING: CPU: 0 PID: 5321 at fs/btrfs/extent-tree.c:836 lookup_inline_extent_backref+0x12c7/0x17f0 fs/btrfs/extent-tree.c:836
Modules linked in:
CPU: 0 UID: 0 PID: 5321 Comm: syz.0.0 Not tainted syzkaller #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
RIP: 0010:lookup_inline_extent_backref+0x12c7/0x17f0 fs/btrfs/extent-tree.c:836
Code: 05 6e 23 a5 0e 48 3b 84 24 e0 01 00 00 0f 85 8e 04 00 00 89 d8 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 cb 47 81 07 cc 90 <0f> 0b 90 48 8b 44 24 78 42 80 3c 30 00 74 0a 48 8b 7c 24 20 e8 00
RSP: 0018:ffffc9000d4ce820 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff88803331c900 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000d4cea48 R08: 0000000000000000 R09: 1ffffd40000e0748
R10: dffffc0000000000 R11: fffff940000e0749 R12: 1ffff11003824e9a
R13: 00000000000000b2 R14: dffffc0000000000 R15: ffff888011eae000
FS:  00007fd3e49f16c0(0000) GS:ffff88808d733000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd3d7a3f000 CR3: 0000000042800000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 insert_inline_extent_backref+0xa8/0x2f0 fs/btrfs/extent-tree.c:1205
 __btrfs_inc_extent_ref+0x263/0x9e0 fs/btrfs/extent-tree.c:1503
 run_one_delayed_ref fs/btrfs/extent-tree.c:-1 [inline]
 btrfs_run_delayed_refs_for_head fs/btrfs/extent-tree.c:1972 [inline]
 __btrfs_run_delayed_refs+0xebd/0x4130 fs/btrfs/extent-tree.c:2047
 btrfs_run_delayed_refs+0xe6/0x3b0 fs/btrfs/extent-tree.c:2159
 btrfs_start_dirty_block_groups+0xd3d/0x10a0 fs/btrfs/block-group.c:3534
 btrfs_commit_transaction+0x674/0x3950 fs/btrfs/transaction.c:2241
 btrfs_sync_file+0xd30/0x1160 fs/btrfs/file.c:1818
 generic_write_sync include/linux/fs.h:3046 [inline]
 btrfs_do_write_iter+0x59a/0x710 fs/btrfs/file.c:1469
 iter_file_splice_write+0x975/0x10e0 fs/splice.c:738
 do_splice_from fs/splice.c:938 [inline]
 direct_splice_actor+0x101/0x160 fs/splice.c:1161
 splice_direct_to_actor+0x5a8/0xcc0 fs/splice.c:1105
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0x181/0x270 fs/splice.c:1230
 do_sendfile+0x4da/0x7e0 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1417
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd3e3b8efc9
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:00007fd3e49f1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007fd3e3de6090 RCX: 00007fd3e3b8efc9
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000009
RBP: 00007fd3e3c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 000000007ffff000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd3e3de6128 R14: 00007fd3e3de6090 R15: 00007ffc3dbcf578
 </TASK>