# CVE-2025-71065: f2fs: fix to avoid potential deadlock

> A deadlock in the Linux kernel f2fs filesystem can cause a system hang, requiring a local attacker to trigger specific memory pressure conditions.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Jan 2026
- **Updated:** 11 May 2026
- **Also known as:** AZL-74384, BELL-CVE-2025-71065, DEBIAN-CVE-2025-71065, GHSA-v4p5-6x9m-jprj, ROOT-OS-DEBIAN-12-CVE-2025-71065, ROOT-OS-DEBIAN-13-CVE-2025-71065, ROOT-OS-UBUNTU-2404-CVE-2025-71065, UBUNTU-CVE-2025-71065

## What is CVE-2025-71065?

CVE-2025-71065 is a vulnerability in Linux, published on 13 Jan 2026. 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 potential deadlock

As Jiaming Zhang and syzbot reported, there is potential deadlock in
f2fs as below:

Chain exists of:
  &sbi->cp_rwsem --> fs_reclaim --> sb_internal#2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(sb_internal#2);
                               lock(fs_reclaim);
                               lock(sb_internal#2);
  rlock(&sbi->cp_rwsem);

 *** DEADLOCK ***

3 locks held by kswapd0/73:
 #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7015 [inline]
 #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x951/0x2800 mm/vmscan.c:7389
 #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline]
 #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_cache_scan+0x91/0x4b0 fs/super.c:197
 #2: ffff888011840610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x8d9/0x1b60 fs/f2fs/inode.c:890

stack backtrace:
CPU: 0 UID: 0 PID: 73 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537
 f2fs_down_read fs/f2fs/f2fs.h:2278 [inline]
 f2fs_lock_op fs/f2fs/f2fs.h:2357 [inline]
 f2fs_do_truncate_blocks+0x21c/0x10c0 fs/f2fs/file.c:791
 f2fs_truncate_blocks+0x10a/0x300 fs/f2fs/file.c:867
 f2fs_truncate+0x489/0x7c0 fs/f2fs/file.c:925
 f2fs_evict_inode+0x9f2/0x1b60 fs/f2fs/inode.c:897
 evict+0x504/0x9c0 fs/inode.c:810
 f2fs_evict_inode+0x1dc/0x1b60 fs/f2fs/inode.c:853
 evict+0x504/0x9c0 fs/inode.c:810
 dispose_list fs/inode.c:852 [inline]
 prune_icache_sb+0x21b/0x2c0 fs/inode.c:1000
 super_cache_scan+0x39b/0x4b0 fs/super.c:224
 do_shrink_slab+0x6ef/0x1110 mm/shrinker.c:437
 shrink_slab_memcg mm/shrinker.c:550 [inline]
 shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628
 shrink_one+0x28a/0x7c0 mm/vmscan.c:4955
 shrink_many mm/vmscan.c:5016 [inline]
 lru_gen_shrink_node mm/vmscan.c:5094 [inline]
 shrink_node+0x315d/0x3780 mm/vmscan.c:6081
 kswapd_shrink_node mm/vmscan.c:6941 [inline]
 balance_pgdat mm/vmscan.c:7124 [inline]
 kswapd+0x147c/0x2800 mm/vmscan.c:7389
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The root cause is deadlock among four locks as below:

kswapd
- fs_reclaim				--- Lock A
 - shrink_one
  - evict
   - f2fs_evict_inode
    - sb_start_intwrite			--- Lock B

- iput
 - evict
  - f2fs_evict_inode
   - sb_start_intwrite			--- Lock B
   - f2fs_truncate
    - f2fs_truncate_blocks
     - f2fs_do_truncate_blocks
      - f2fs_lock_op			--- Lock C

ioctl
- f2fs_ioc_commit_atomic_write
 - f2fs_lock_op				--- Lock C
  - __f2fs_commit_atomic_write
   - __replace_atomic_write_block
    - f2fs_get_dnode_of_data
     - __get_node_folio
      - f2fs_check_nid_range
       - f2fs_handle_error
        - f2fs_record_errors
         - f2fs_down_write		--- Lock D

open
- do_open
 - do_truncate
  - security_inode_need_killpriv
   - f2fs_getxattr
    - lookup_all_xattrs
     - f2fs_handle_error
      - f2fs_record_errors
       - f2fs_down_write		--- Lock D
        - f2fs_commit_super
         - read_mapping_folio
          - filemap_alloc_folio_noprof
           - prepare_alloc_pages
            - fs_reclaim_acquire	--- Lock A

In order to a
---truncated---

## Which versions are affected by CVE-2025-71065?


## How do I fix CVE-2025-71065?

Apply the vendor's patch.

## Is CVE-2025-71065 being exploited?

There is no known exploitation of CVE-2025-71065 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-71065 and fix it if it is affected.

What it is: CVE-2025-71065 is a vulnerability in Linux, published on 13 Jan 2026. 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-2025-71065 in the wild and no public exploit code.

Affected product: 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-2025-71065/ (Markdown: https://insights.sbomify.com/CVE-2025-71065/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-71065
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-71065
- OSV: https://osv.dev/vulnerability/CVE-2025-71065

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-71065/
Summaries are generated and may contain mistakes; the official description above is the record.
