# CVE-2025-38578: f2fs: fix to avoid UAF in f2fs_sync_inode_meta()

> A use-after-free vulnerability in the Linux kernel's f2fs filesystem allows attackers to cause a denial of service or potentially execute code.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Aug 2025
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-66521, BELL-CVE-2025-38578, DEBIAN-CVE-2025-38578, GHSA-q6w5-3c4x-vchv, ROOT-OS-DEBIAN-11-CVE-2025-38578, ROOT-OS-DEBIAN-12-CVE-2025-38578, ROOT-OS-DEBIAN-13-CVE-2025-38578, ROOT-OS-UBUNTU-2204-CVE-2025-38578, ROOT-OS-UBUNTU-2404-CVE-2025-38578, UBUNTU-CVE-2025-38578

## What is CVE-2025-38578?

CVE-2025-38578 is a high-severity use after free vulnerability in Debian Debian Linux, published on 19 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix to avoid UAF in f2fs_sync_inode_meta()

syzbot reported an UAF issue as below: [1] [2]

[1] https://syzkaller.appspot.com/text?tag=CrashReport&x=16594c60580000

==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62
Read of size 8 at addr ffff888100567dc8 by task kworker/u4:0/8

CPU: 1 PID: 8 Comm: kworker/u4:0 Tainted: G        W          6.1.129-syzkaller-00017-g642656a36791 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0x158/0x4e0 mm/kasan/report.c:427
 kasan_report+0x13c/0x170 mm/kasan/report.c:531
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351
 __list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62
 __list_del_entry include/linux/list.h:134 [inline]
 list_del_init include/linux/list.h:206 [inline]
 f2fs_inode_synced+0x100/0x2e0 fs/f2fs/super.c:1553
 f2fs_update_inode+0x72/0x1c40 fs/f2fs/inode.c:588
 f2fs_update_inode_page+0x135/0x170 fs/f2fs/inode.c:706
 f2fs_write_inode+0x416/0x790 fs/f2fs/inode.c:734
 write_inode fs/fs-writeback.c:1460 [inline]
 __writeback_single_inode+0x4cf/0xb80 fs/fs-writeback.c:1677
 writeback_sb_inodes+0xb32/0x1910 fs/fs-writeback.c:1903
 __writeback_inodes_wb+0x118/0x3f0 fs/fs-writeback.c:1974
 wb_writeback+0x3da/0xa00 fs/fs-writeback.c:2081
 wb_check_background_flush fs/fs-writeback.c:2151 [inline]
 wb_do_writeback fs/fs-writeback.c:2239 [inline]
 wb_workfn+0xbba/0x1030 fs/fs-writeback.c:2266
 process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299
 worker_thread+0xa60/0x1260 kernel/workqueue.c:2446
 kthread+0x26d/0x300 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Allocated by task 298:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:333
 kasan_slab_alloc include/linux/kasan.h:202 [inline]
 slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768
 slab_alloc_node mm/slub.c:3421 [inline]
 slab_alloc mm/slub.c:3431 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3438 [inline]
 kmem_cache_alloc_lru+0x102/0x270 mm/slub.c:3454
 alloc_inode_sb include/linux/fs.h:3255 [inline]
 f2fs_alloc_inode+0x2d/0x350 fs/f2fs/super.c:1437
 alloc_inode fs/inode.c:261 [inline]
 iget_locked+0x18c/0x7e0 fs/inode.c:1373
 f2fs_iget+0x55/0x4ca0 fs/f2fs/inode.c:486
 f2fs_lookup+0x3c1/0xb50 fs/f2fs/namei.c:484
 __lookup_slow+0x2b9/0x3e0 fs/namei.c:1689
 lookup_slow+0x5a/0x80 fs/namei.c:1706
 walk_component+0x2e7/0x410 fs/namei.c:1997
 lookup_last fs/namei.c:2454 [inline]
 path_lookupat+0x16d/0x450 fs/namei.c:2478
 filename_lookup+0x251/0x600 fs/namei.c:2507
 vfs_statx+0x107/0x4b0 fs/stat.c:229
 vfs_fstatat fs/stat.c:267 [inline]
 vfs_lstat include/linux/fs.h:3434 [inline]
 __do_sys_newlstat fs/stat.c:423 [inline]
 __se_sys_newlstat+0xda/0x7c0 fs/stat.c:417
 __x64_sys_newlstat+0x5b/0x70 fs/stat.c:417
 x64_sys_call+0x52/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:7
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 0:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249
 kasan_slab_free include/linux/kasan.h:178 [inline]
 slab_free_hook mm/slub.c:1745 [inline]
 slab_free_freelist_hook mm/slub.c:1771 [inline]
 slab_free mm/slub.c:3686 [inline]
 kmem_cache_free+0x
---truncated---

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-38578?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2025-38578?

Apply the vendor's patch.

## Is CVE-2025-38578 being exploited?

There is no known exploitation of CVE-2025-38578 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-38578 and fix it if it is affected.

What it is: CVE-2025-38578 is a high-severity use after free vulnerability in Debian Debian Linux, published on 19 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-38578 in the wild and no public exploit code.

Affected product: Debian Debian Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-38578/ (Markdown: https://insights.sbomify.com/CVE-2025-38578/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-38578
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-38578
- OSV: https://osv.dev/vulnerability/CVE-2025-38578

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-38578/
Summaries are generated and may contain mistakes; the official description above is the record.
