syzbot


WARNING in f2fs_rename2

Status: upstream: reported C repro on 2026/02/27 08:52
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+abd21c28d385a6b54352@syzkaller.appspotmail.com
First crash: 4d17h, last: 4d02h
Bug presence (2)
Date Name Commit Repro Result
2026/02/27 linux-6.6.y (ToT) 7a137e9bfa0e C [report] WARNING in f2fs_rename2
2026/02/27 upstream (ToT) 4d349ee5c778 C Didn't crash
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in f2fs_rename2 origin:lts-only -1 C error 4 16d 71d 0/3 upstream: reported C repro on 2025/12/22 13:22
upstream WARNING in f2fs_rename2 f2fs -1 C done 66 345d 463d 0/29 closed as dup on 2025/02/11 07:37
linux-5.15 WARNING in f2fs_rename2 missing-backport origin:upstream -1 C error 3 24d 417d 0/3 upstream: reported C repro on 2025/01/10 15:28
upstream WARNING in f2fs_rename2 (2) f2fs -1 C 5 128d 141d 29/29 fixed on 2026/01/07 12:29
Fix bisection attempts (1)
Created Duration User Patch Repo Result
2026/03/01 15:13 1m fix candidate upstream error job log

Sample crash report:
F2FS-fs (loop0): Wrong NAT boundary, start(2560) end(3584) blocks(0)
F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock
F2FS-fs (loop0): invalid crc value
F2FS-fs (loop0): Found nat_bits in checkpoint
F2FS-fs (loop0): Try to recover 1th superblock, ret: 0
F2FS-fs (loop0): Mounted with checkpoint version = 48b305e4
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5923 at fs/inode.c:332 drop_nlink+0xbf/0x100 fs/inode.c:332
Modules linked in:
CPU: 1 PID: 5923 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:drop_nlink+0xbf/0x100 fs/inode.c:332
Code: 48 8b 1b 48 8d bb 78 07 00 00 be 08 00 00 00 e8 e7 12 ea ff f0 48 ff 83 78 07 00 00 5b 41 5c 41 5e 41 5f 5d c3 e8 61 e1 91 ff <0f> 0b eb 88 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 62 ff ff ff 4c
RSP: 0018:ffffc90003207930 EFLAGS: 00010293
RAX: ffffffff81f533af RBX: ffff8880600f2400 RCX: ffff88807b3c3c00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff8880600f28bf R09: 1ffff1100c01e517
R10: dffffc0000000000 R11: ffffed100c01e518 R12: 1ffff1100c01e48b
R13: ffff8880600f2400 R14: ffff8880600f2458 R15: dffffc0000000000
FS:  000055556292c500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34263fff CR3: 00000000776ca000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 f2fs_i_links_write fs/f2fs/f2fs.h:3127 [inline]
 f2fs_rename fs/f2fs/namei.c:1008 [inline]
 f2fs_rename2+0x1633/0x2270 fs/f2fs/namei.c:1283
 vfs_rename+0xba2/0xed0 fs/namei.c:4880
 do_renameat2+0x8e9/0xce0 fs/namei.c:5033
 __do_sys_rename fs/namei.c:5079 [inline]
 __se_sys_rename fs/namei.c:5077 [inline]
 __x64_sys_rename+0x86/0x90 fs/namei.c:5077
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa9f8f9c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007fffa06a1ae8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007fa9f9215fa0 RCX: 00007fa9f8f9c799
RDX: 0000000000000000 RSI: 00002000000000c0 RDI: 0000200000000040
RBP: 00007fa9f9032bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa9f9215fac R14: 00007fa9f9215fa0 R15: 00007fa9f9215fa0
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/27 11:42 linux-6.6.y 7a137e9bfa0e a2f13f71 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan WARNING in f2fs_rename2
2026/02/27 08:51 linux-6.6.y 7a137e9bfa0e a2f13f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in f2fs_rename2
* Struck through repros no longer work on HEAD.