------------[ cut here ]------------
btrfs_abort_should_print_stack(__error)
WARNING: fs/btrfs/extent-tree.c:3429 at __btrfs_free_extent+0x1fd1/0x39c0 fs/btrfs/extent-tree.c:3429, CPU#0: kworker/u4:0/12
Modules linked in:
CPU: 0 UID: 0 PID: 12 Comm: kworker/u4:0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: events_unbound btrfs_async_reclaim_metadata_space
RIP: 0010:__btrfs_free_extent+0x1fd1/0x39c0 fs/btrfs/extent-tree.c:3429
Code: 0c ba fd 45 85 f6 0f 85 e0 05 00 00 e8 f8 06 ba fd e9 47 09 00 00 e8 ee 06 ba fd eb 10 e8 e7 06 ba fd eb 09 e8 e0 06 ba fd 90 <0f> 0b 90 4c 8b 7c 24 10 44 89 e1 f7 d9 e9 93 e7 ff ff e8 68 9a c9
RSP: 0018:ffffc9000025f280 EFLAGS: 00010293
RAX: ffffffff840d1fb0 RBX: ffff88804f348001 RCX: ffff88801cef4b00
RDX: 0000000000000000 RSI: ffffffff8f1b9ee0 RDI: 00000000ffffffe4
RBP: ffffc9000025f430 R08: ffff88801cef4b00 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000000 R12: 00000000ffffffe4
R13: ffff8880518ea178 R14: dffffc0000000000 R15: 00000000ffffffe4
FS:  0000000000000000(0000) GS:ffff88808c533000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000001fdb8000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 run_delayed_tree_ref fs/btrfs/extent-tree.c:1824 [inline]
 run_one_delayed_ref fs/btrfs/extent-tree.c:1851 [inline]
 btrfs_run_delayed_refs_for_head fs/btrfs/extent-tree.c:2058 [inline]
 __btrfs_run_delayed_refs+0x166c/0x43b0 fs/btrfs/extent-tree.c:2134
 btrfs_run_delayed_refs+0xdc/0x2a0 fs/btrfs/extent-tree.c:2246
 flush_space+0x56d/0xde0 fs/btrfs/space-info.c:-1
 do_async_reclaim_metadata_space+0x3e8/0x940 fs/btrfs/space-info.c:1211
 btrfs_async_reclaim_metadata_space+0x89/0xe0 fs/btrfs/space-info.c:1278
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa88/0x14c0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>