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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
Fix commit: f2fs: Add sanity checks before unlinking and loading inodes
Patched on: [ci-upstream-linux-next-kasan-gce-root ci-upstream-rust-kasan-gce], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 50d, last: 35d
▶ ▼ Discussions (5)
Title Replies (including bot) Last reply
[PATCH v4 2/2] f2fs: Add sanity checks before unlinking and loading inodes 2 (2) 2025/11/05 11:14
[syzbot] [f2fs?] WARNING in f2fs_delete_entry (2) 0 (7) 2025/11/05 10:52
[PATCH v3 2/2] f2fs: Add sanity checks before unlinking and loading inodes 2 (2) 2025/11/05 07:27
[PATCH v2 2/2] f2fs: Add sanity checks before unlinking and loading inodes 4 (4) 2025/11/03 08:12
[PATCH] f2fs: Perform sanity check before unlinking directory inode 10 (10) 2025/10/27 08:12
▶ ▼ 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 153d 359d 0/3 upstream: reported C repro on 2024/11/21 21:29
upstream WARNING in f2fs_delete_entry f2fs -1 C 71 222d 358d 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 158d 359d 0/3 auto-obsoleted due to no activity on 2025/09/18 06:39
▶ ▼ Last patch testing requests (9)
Created Duration User Patch Repo Result
2025/11/05 10:52 40m zlatistiv@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2025/11/03 15:39 3h20m zlatistiv@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2025/10/27 22:13 1h16m zlatistiv@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2025/10/12 21:03 26m zlatistiv@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2025/10/11 05:34 41m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/10/11 05:34 25m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/10/11 05:34 23m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/10/02 22:20 25m zlatistiv@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2025/10/01 18:24 2h07m zlatistiv@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log

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.