WARNING in nilfs_rmdir (3)

Status: upstream: reported on 2026/09/28 21:44
Subsystems: nilfs
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+c388db0347b7fc88fa7a@syzkaller.appspotmail.com
First crash: 4d02h, last: 4d02h
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
bd10f679 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ WARNING in nilfs_rmdir (3) 2026/09/26 01:03 2026/09/26 01:03 2026/09/26 01:33 f281d9d2
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [nilfs?] WARNING in nilfs_rmdir (3) 0 (1) 2026/09/28 21:44
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in nilfs_rmdir -1 syz, C done 42 646d 669d 3/3 fixed on 2025/01/28 12:20
upstream WARNING in nilfs_rmdir (2) prio:low nilfs -1 1 188d 184d 0/29 auto-obsoleted due to no activity on 2026/07/02 20:36
linux-5.15 WARNING in nilfs_rmdir origin:lts-only -1 syz, C done 4 645d 652d 3/3 fixed on 2025/01/30 02:24
upstream WARNING in nilfs_rmdir nilfs -1 syz, C error 295 630d 677d 28/29 fixed on 2025/05/06 15:33

Sample crash report:
NILFS (loop3): deleting nonexistent file (ino=12), 0
------------[ cut here ]------------
inode->i_nlink == 0
WARNING: fs/inode.c:408 at drop_nlink+0xc5/0x110 fs/inode.c:408, CPU#1: syz-executor/5581
Modules linked in:
CPU: 1 UID: 0 PID: 5581 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:drop_nlink+0xc5/0x110 fs/inode.c:408
Code: 50 09 00 00 be 08 00 00 00 e8 67 46 e9 ff f0 48 ff 83 50 09 00 00 5b 41 5c 41 5e 41 5f 5d e9 d2 29 12 09 cc e8 dc 54 7d ff 90 <0f> 0b 90 eb 81 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 5b ff ff ff
RSP: 0018:ffffc9000587fc70 EFLAGS: 00010293
RAX: ffffffff82495fd4 RBX: ffff88803f613d78 RCX: ffff888037560000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed10053f5d2b R12: 1ffff11007ec27b8
R13: ffff88803f613d78 R14: ffff88803f613dc0 R15: dffffc0000000000
FS:  0000555567408500(0000) GS:ffff888125cc7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f52937858b8 CR3: 0000000058ee4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 nilfs_rmdir+0x1b4/0x250 fs/nilfs2/namei.c:347
 vfs_rmdir+0x3e9/0x6b0 fs/namei.c:5515
 filename_rmdir+0x292/0x520 fs/namei.c:5572
 __do_sys_unlinkat fs/namei.c:5747 [inline]
 __se_sys_unlinkat+0x71/0x1a0 fs/namei.c:5740
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a90c2d277
Code: 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 b8 07 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdb3170b78 EFLAGS: 00000207 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f5a90c2d277
RDX: 0000000000000200 RSI: 00007ffdb3171d20 RDI: 00000000ffffff9c
RBP: 00007f5a90cc44bb R08: 0000000000008560 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000207 R12: 00007ffdb3171d20
R13: 00007f5a90cc44bb R14: 00000000000296e0 R15: 00007ffdb3173ee0
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/24 21:32 upstream f49a343b305c 3c3cdf19 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING in nilfs_rmdir
* Struck through repros no longer work on HEAD.