kernel BUG in nilfs_delete_entry

Status: upstream: reported syz repro on 2025/02/24 01:48
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+82175cd88f011b58117a@syzkaller.appspotmail.com
First crash: 518d, last: 501d
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/03/13 linux-6.1.y (ToT) 6ae7ac5c4251 syz [report] kernel BUG in nilfs_delete_entry
2025/03/13 upstream (ToT) b7f94fcf5546 syz Didn't crash
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in nilfs_delete_entry nilfs -1 C done 22 555d 818d 28/29 fixed on 2025/05/06 15:33
▶ ▼ Fix bisection attempts (7)
Created Duration User Patch Repo Result
2026/05/17 08:39 18m fix candidate upstream error job log
2026/03/26 09:37 1m fix candidate upstream error job log
2026/02/22 19:23 1m fix candidate upstream error job log
2026/01/23 01:16 1m fix candidate upstream error job log
2025/08/01 18:47 27m fix candidate upstream error job log
2025/07/01 05:54 19m fix candidate upstream error job log
2025/06/27 10:10 19m bisect fix linux-6.1.y error job log

Sample crash report:
Remounting filesystem read-only
------------[ cut here ]------------
kernel BUG at fs/nilfs2/dir.c:601!
Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 9571 Comm: syz.4.1610 Not tainted 6.1.129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : nilfs_delete_entry+0x5ac/0x5e0 fs/nilfs2/dir.c:601
lr : nilfs_delete_entry+0x5ac/0x5e0 fs/nilfs2/dir.c:601
sp : ffff800023ea7950
x29: ffff800023ea7960 x28: ffff0000f75b4038 x27: dfff800000000000
x26: 00000000fffffffb x25: 0000000000000030 x24: 0000000000000068
x23: 0000000000000038 x22: ffff0000f404bd28 x21: ffff0000f404bb00
x20: ffff0000f75b4050 x19: fffffc0003dd6d00 x18: 0000000000000000
x17: 0000000000000000 x16: ffff80001232176c x15: 0000000000000000
x14: 00000000ffffffff x13: 000000000005c768 x12: 0000000000000001
x11: 0000000000ff0100 x10: 0000000000000000 x9 : ffff800009e1d3bc
x8 : ffff0000f2780000 x7 : 000000000005c768 x6 : 000000000005c6f8
x5 : ffff800023ea6d78 x4 : ffff800015ba5cc8 x3 : ffff8000082fa834
x2 : 0000000000000068 x1 : 00000000fffffffb x0 : 0000000000000000
Call trace:
 nilfs_delete_entry+0x5ac/0x5e0 fs/nilfs2/dir.c:601
 nilfs_do_unlink+0x168/0x260 fs/nilfs2/namei.c:299
 nilfs_unlink+0xe8/0x1bc fs/nilfs2/namei.c:319
 vfs_unlink+0x2f0/0x508 fs/namei.c:4322
 do_unlinkat+0x4cc/0x70c fs/namei.c:4390
 __do_sys_unlinkat fs/namei.c:4433 [inline]
 __se_sys_unlinkat fs/namei.c:4426 [inline]
 __arm64_sys_unlinkat+0xcc/0xfc fs/namei.c:4426
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
Code: aa1803e0 97a85a0b d4210000 979b5942 (d4210000) 
---[ end trace 0000000000000000 ]---

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/24 01:47 linux-6.1.y 3a8358583626 d34966d1 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 kernel BUG in nilfs_delete_entry
* Struck through repros no longer work on HEAD.