syzbot


WARNING in __btrfs_run_delayed_items (2)

Status: upstream: reported on 2025/12/07 09:53
Subsystems: btrfs
[Documentation on labels]
Reported-by: syzbot+64c9efba06e7ad505aef@syzkaller.appspotmail.com
First crash: 100d, last: 23d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [btrfs?] WARNING in __btrfs_run_delayed_items (2) 0 (1) 2025/12/07 09:53
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in __btrfs_run_delayed_items btrfs -1 syz unreliable unreliable 4 918d 920d 0/29 auto-obsoleted due to no activity on 2023/12/16 04:42

Sample crash report:
------------[ cut here ]------------
BTRFS: Transaction aborted (error -28)
WARNING: fs/btrfs/delayed-inode.c:1162 at __btrfs_run_delayed_items+0x443/0x510 fs/btrfs/delayed-inode.c:1162, CPU#0: kworker/u4:3/37
Modules linked in:
CPU: 0 UID: 0 PID: 37 Comm: kworker/u4:3 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_run_delayed_items+0x445/0x510 fs/btrfs/delayed-inode.c:1162
Code: 45 85 f6 75 07 e8 4b 54 c1 fd eb 79 e8 14 59 a6 fd 84 c0 74 1f e8 3b 54 c1 fd eb 69 e8 34 54 c1 fd 48 8d 3d 7d c7 16 0c 89 ee <67> 48 0f b9 3a e9 e1 fe ff ff e8 9c b4 aa 07 41 89 c6 31 ff 89 c6
RSP: 0018:ffffc900003f77b0 EFLAGS: 00010293
RAX: ffffffff8404434c RBX: ffff888035ed2370 RCX: ffff88801eb3c900
RDX: 0000000000000000 RSI: 00000000ffffffe4 RDI: ffffffff901b0ad0
RBP: 00000000ffffffe4 R08: ffff88801eb3c900 R09: 0000000000000003
R10: 00000000fffffffb R11: 0000000000000000 R12: 0000000000000000
R13: ffff888041ecc3d0 R14: ffff888042b1c001 R15: 1ffff11006bda46e
FS:  0000000000000000(0000) GS:ffff88808ca5b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa8b2fff000 CR3: 0000000012855000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 flush_space+0x569/0xd80 fs/btrfs/space-info.c:863
 do_async_reclaim_metadata_space+0x3fc/0x960 fs/btrfs/space-info.c:1187
 btrfs_async_reclaim_metadata_space+0x89/0xe0 fs/btrfs/space-info.c:1254
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess):
   0:	45 85 f6             	test   %r14d,%r14d
   3:	75 07                	jne    0xc
   5:	e8 4b 54 c1 fd       	call   0xfdc15455
   a:	eb 79                	jmp    0x85
   c:	e8 14 59 a6 fd       	call   0xfda65925
  11:	84 c0                	test   %al,%al
  13:	74 1f                	je     0x34
  15:	e8 3b 54 c1 fd       	call   0xfdc15455
  1a:	eb 69                	jmp    0x85
  1c:	e8 34 54 c1 fd       	call   0xfdc15455
  21:	48 8d 3d 7d c7 16 0c 	lea    0xc16c77d(%rip),%rdi        # 0xc16c7a5
  28:	89 ee                	mov    %ebp,%esi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	e9 e1 fe ff ff       	jmp    0xffffff15
  34:	e8 9c b4 aa 07       	call   0x7aab4d5
  39:	41 89 c6             	mov    %eax,%r14d
  3c:	31 ff                	xor    %edi,%edi
  3e:	89 c6                	mov    %eax,%esi

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/18 13:16 upstream 2961f841b025 39751c21 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in __btrfs_run_delayed_items
2025/12/03 09:47 upstream 44fc84337b6e d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in __btrfs_run_delayed_items
* Struck through repros no longer work on HEAD.