WARNING in xfs_bmapi_convert_delalloc (2)

Status: upstream: reported C repro on 2025/04/04 07:22
Bug presence: origin:upstream
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+9d988404f10c4ebd4189@syzkaller.appspotmail.com
First crash: 577d, last: 45d
Fix bisection: the issue occurs on the latest tested release (bisect log)
Crash: WARNING in xfs_bmapi_convert_delalloc (log)
Repro: C syz .config
  
▶ ▼ Bug presence (3)
Date Name Commit Repro Result
2025/05/31 linux-5.15.y (ToT) 98f47d0e9b8c C [report] WARNING in xfs_bmapi_convert_delalloc
2025/04/06 upstream (ToT) 0af2f6be1b42 C [report] unregister_netdevice: waiting for DEV to become free
2025/05/31 upstream (ToT) 0f70f5b08a47 C Didn't crash
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in xfs_bmapi_convert_delalloc (3) prio:high xfs -1 2 52d 90d 0/29 upstream: reported on 2026/08/04 01:05
upstream WARNING in xfs_bmapi_convert_delalloc no-reminders xfs -1 syz, C unreliable done 559 903d 1437d 0/29 auto-obsoleted due to no activity on 2024/07/22 07:09
linux-6.1 WARNING in xfs_bmapi_convert_delalloc origin:upstream missing-backport -1 syz, C inconclusive 7 800d 1264d 0/3 upstream: reported C repro on 2023/05/18 14:29
upstream WARNING in xfs_bmapi_convert_delalloc (2) xfs -1 syz, C 4 582d 677d 0/29 auto-obsoleted due to no activity on 2025/07/08 14:13
linux-5.15 WARNING in xfs_bmapi_convert_delalloc origin:upstream missing-backport -1 syz, C error 6 854d 1263d 0/3 auto-obsoleted due to no activity on 2024/10/10 08:11
▶ ▼ Last patch testing requests (6)
Created Duration User Patch Repo Result
2026/09/18 01:33 12m retest repro linux-5.15.y report job log log
2026/06/23 04:12 16m retest repro linux-5.15.y report log
2026/04/06 05:46 24m retest repro linux-5.15.y report log
2026/01/25 19:30 9m retest repro linux-5.15.y report log
2025/11/16 15:32 1h00m retest repro linux-5.15.y report log
2025/04/18 07:26 10m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (10)
Created Duration User Patch Repo Result
2026/05/12 11:41 20m fix candidate upstream error job log
2026/03/28 07:44 1m fix candidate upstream error job log
2026/02/24 18:24 3m fix candidate upstream error job log
2026/01/24 01:47 1m fix candidate upstream error job log
2025/11/04 18:12 12h10m fix candidate upstream error job log
2025/09/24 20:01 12h11m fix candidate upstream error job log
2025/09/06 13:53 2h12m bisect fix linux-5.15.y OK (0) job log log
2025/08/01 16:37 2h06m bisect fix linux-5.15.y OK (0) job log log
2025/06/30 21:29 1h29m bisect fix linux-5.15.y OK (0) job log log
2025/05/21 19:51 1h44m bisect fix linux-5.15.y OK (0) job log log

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1221 at fs/xfs/libxfs/xfs_bmap.c:4641 xfs_bmapi_convert_delalloc+0xe91/0x1180 fs/xfs/libxfs/xfs_bmap.c:-1
Modules linked in:
CPU: 1 PID: 1221 Comm: kworker/u4:4 Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:xfs_bmapi_convert_delalloc+0xe91/0x1180 fs/xfs/libxfs/xfs_bmap.c:4641
Code: e5 23 82 fe 0f 0b e9 c8 f4 ff ff 89 d9 80 e1 07 38 c1 0f 8c f0 f2 ff ff 48 89 df e8 e9 15 cc fe e9 e3 f2 ff ff e8 bf 23 82 fe <0f> 0b 41 bd e4 ff ff ff 48 8b 5c 24 08 e9 62 ff ff ff e8 a8 23 82
RSP: 0018:ffffc90004886a20 EFLAGS: 00010293
RAX: ffffffff82fe7901 RBX: ffffffffffffffff RCX: ffff888022395940
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: ffffffffffffffff
RBP: ffffc90004886c50 R08: ffffffff82fe7317 R09: fffffbfff1c153f6
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffffc90004886b60 R14: ffffc90004886b00 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbb618ee2b8 CR3: 000000002af1a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 xfs_convert_blocks fs/xfs/xfs_aops.c:245 [inline]
 xfs_map_blocks+0xa9e/0x1520 fs/xfs/xfs_aops.c:366
 iomap_writepage_map fs/iomap/buffered-io.c:1320 [inline]
 iomap_do_writepage+0x63c/0x21c0 fs/iomap/buffered-io.c:1485
 write_cache_pages+0xa97/0x1160 mm/page-writeback.c:2277
 iomap_writepages+0x64/0x240 fs/iomap/buffered-io.c:1516
 xfs_vm_writepages+0x127/0x180 fs/xfs/xfs_aops.c:488
 do_writepages+0x481/0x730 mm/page-writeback.c:2386
 __writeback_single_inode+0x15b/0xe30 fs/fs-writeback.c:1647
 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1930
 wb_writeback+0x451/0xc50 fs/fs-writeback.c:2104
 wb_do_writeback fs/fs-writeback.c:2247 [inline]
 wb_workfn+0x46c/0x1130 fs/fs-writeback.c:2288
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/04 07:21 linux-5.15.y 0c935c049b5c d7ae3a11 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan WARNING in xfs_bmapi_convert_delalloc
2026/02/06 22:25 linux-5.15.y 7b232985052f 97745f52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in xfs_bmapi_convert_delalloc
* Struck through repros no longer work on HEAD.