syzbot


WARNING in f2fs_delete_entry (2)

Status: upstream: reported C repro on 2025/09/29 19:33
Subsystems: f2fs
[Documentation on labels]
Reported-by: syzbot+c07d47c7bc68f47b9083@syzkaller.appspotmail.com
First crash: 3d18h, last: 3d11h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [f2fs?] WARNING in f2fs_delete_entry (2) 0 (1) 2025/09/29 19:33
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in f2fs_delete_entry origin:upstream missing-backport -1 C error 8 106d 312d 0/3 upstream: reported C repro on 2024/11/21 21:29
upstream WARNING in f2fs_delete_entry f2fs -1 C 71 176d 311d 0/29 closed as dup on 2024/11/25 18:18
linux-5.15 WARNING in f2fs_delete_entry missing-backport -1 C error 11 112d 312d 0/3 auto-obsoleted due to no activity on 2025/09/18 06:39

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6642 at fs/inode.c:417 drop_nlink+0xe4/0x138 fs/inode.c:417
Modules linked in:
CPU: 0 UID: 0 PID: 6642 Comm: syz-executor Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : drop_nlink+0xe4/0x138 fs/inode.c:417
lr : drop_nlink+0xe4/0x138 fs/inode.c:417
sp : ffff8000a54b79a0
x29: ffff8000a54b79a0 x28: dfff800000000000 x27: ffff0000efc5d000
x26: dfff800000000000 x25: 0000000200000000 x24: 0000000000000000
x23: 1fffe0001d284485 x22: dfff800000000000 x21: 0000000000000000
x20: ffff0000e9422428 x19: ffff0000e94223e0 x18: 0000000000000000
x17: 0000000000000000 x16: ffff8000805379bc x15: 0000000000000001
x14: 1fffe0001bd69171 x13: 0000000000000000 x12: 0000000000000000
x11: ffff60001bd69172 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : ffff0000cdeb8000 x7 : ffff8000826e1b78 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff800080537ac4
x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
 drop_nlink+0xe4/0x138 fs/inode.c:417 (P)
 f2fs_i_links_write fs/f2fs/f2fs.h:3233 [inline]
 f2fs_drop_nlink+0x104/0x2e8 fs/f2fs/dir.c:849
 f2fs_delete_entry+0x740/0x9a8 fs/f2fs/dir.c:911
 f2fs_unlink+0x344/0xa3c fs/f2fs/namei.c:590
 f2fs_rmdir+0x5c/0x7c fs/f2fs/namei.c:755
 vfs_rmdir+0x328/0x464 fs/namei.c:4461
 do_rmdir+0x214/0x4c4 fs/namei.c:4516
 __do_sys_unlinkat fs/namei.c:4690 [inline]
 __se_sys_unlinkat fs/namei.c:4684 [inline]
 __arm64_sys_unlinkat+0xc8/0xf8 fs/namei.c:4684
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
irq event stamp: 143176
hardirqs last  enabled at (143175): [<ffff8000806302f8>] seqcount_lockdep_reader_access+0x80/0x104 include/linux/seqlock.h:74
hardirqs last disabled at (143176): [<ffff80008b01a2c4>] el1_brk64+0x20/0x54 arch/arm64/kernel/entry-common.c:434
softirqs last  enabled at (142090): [<ffff800080201608>] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32
softirqs last disabled at (142088): [<ffff8000802015d4>] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19
---[ end trace 0000000000000000 ]---

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/26 21:29 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2213e57a69f0 0abd0691 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-gce-arm64 WARNING in f2fs_delete_entry
2025/09/26 20:20 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2213e57a69f0 0abd0691 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-gce-arm64 WARNING in f2fs_delete_entry
2025/09/26 19:15 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2213e57a69f0 0abd0691 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-gce-arm64 WARNING in f2fs_delete_entry
2025/09/26 14:04 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 35aa5763e111 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in f2fs_delete_entry
* Struck through repros no longer work on HEAD.