# CVE-2024-56744: f2fs: fix to avoid potential deadlock in f2fs_record_stop_reason()

> A deadlock in the f2fs filesystem can cause a system hang, requiring a kernel patch to resolve.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 29 Dec 2024
- **Updated:** 23 May 2026
- **Also known as:** AZL-55035, BELL-CVE-2024-56744, DEBIAN-CVE-2024-56744, GHSA-x63m-j7x3-7j84, ROOT-OS-UBUNTU-2204-CVE-2024-56744, UBUNTU-CVE-2024-56744

## What is CVE-2024-56744?

CVE-2024-56744 is a medium-severity vulnerability in Linux kernel, published on 29 Dec 2024. 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 in f2fs_record_stop_reason()

syzbot reports deadlock issue of f2fs as below:

======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc3-syzkaller-00087-gc964ced77262 #0 Not tainted
------------------------------------------------------
kswapd0/79 is trying to acquire lock:
ffff888011824088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2199 [inline]
ffff888011824088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_record_stop_reason+0x52/0x1d0 fs/f2fs/super.c:4068

but task is already holding lock:
ffff88804bd92610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x662/0x15c0 fs/f2fs/inode.c:842

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (sb_internal#2){.+.+}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1716 [inline]
       sb_start_intwrite+0x4d/0x1c0 include/linux/fs.h:1899
       f2fs_evict_inode+0x662/0x15c0 fs/f2fs/inode.c:842
       evict+0x4e8/0x9b0 fs/inode.c:725
       f2fs_evict_inode+0x1a4/0x15c0 fs/f2fs/inode.c:807
       evict+0x4e8/0x9b0 fs/inode.c:725
       dispose_list fs/inode.c:774 [inline]
       prune_icache_sb+0x239/0x2f0 fs/inode.c:963
       super_cache_scan+0x38c/0x4b0 fs/super.c:223
       do_shrink_slab+0x701/0x1160 mm/shrinker.c:435
       shrink_slab+0x1093/0x14d0 mm/shrinker.c:662
       shrink_one+0x43b/0x850 mm/vmscan.c:4818
       shrink_many mm/vmscan.c:4879 [inline]
       lru_gen_shrink_node mm/vmscan.c:4957 [inline]
       shrink_node+0x3799/0x3de0 mm/vmscan.c:5937
       kswapd_shrink_node mm/vmscan.c:6765 [inline]
       balance_pgdat mm/vmscan.c:6957 [inline]
       kswapd+0x1ca3/0x3700 mm/vmscan.c:7226
       kthread+0x2f0/0x390 kernel/kthread.c:389
       ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #1 (fs_reclaim){+.+.}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       __fs_reclaim_acquire mm/page_alloc.c:3834 [inline]
       fs_reclaim_acquire+0x88/0x130 mm/page_alloc.c:3848
       might_alloc include/linux/sched/mm.h:318 [inline]
       prepare_alloc_pages+0x147/0x5b0 mm/page_alloc.c:4493
       __alloc_pages_noprof+0x16f/0x710 mm/page_alloc.c:4722
       alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
       alloc_pages_noprof mm/mempolicy.c:2345 [inline]
       folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2352
       filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1010
       do_read_cache_folio+0x2eb/0x850 mm/filemap.c:3787
       read_mapping_folio include/linux/pagemap.h:1011 [inline]
       f2fs_commit_super+0x3c0/0x7d0 fs/f2fs/super.c:4032
       f2fs_record_stop_reason+0x13b/0x1d0 fs/f2fs/super.c:4079
       f2fs_handle_critical_error+0x2ac/0x5c0 fs/f2fs/super.c:4174
       f2fs_write_inode+0x35f/0x4d0 fs/f2fs/inode.c:785
       write_inode fs/fs-writeback.c:1503 [inline]
       __writeback_single_inode+0x711/0x10d0 fs/fs-writeback.c:1723
       writeback_single_inode+0x1f3/0x660 fs/fs-writeback.c:1779
       sync_inode_metadata+0xc4/0x120 fs/fs-writeback.c:2849
       f2fs_release_file+0xa8/0x100 fs/f2fs/file.c:1941
       __fput+0x23f/0x880 fs/file_table.c:431
       task_work_run+0x24f/0x310 kernel/task_work.c:228
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
       exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
       __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
       syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
       do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

---truncated---

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2024-56744?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-56744?

Apply the vendor's patch.

## Is CVE-2024-56744 being exploited?

There is no known exploitation of CVE-2024-56744 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-56744 and fix it if it is affected.

What it is: CVE-2024-56744 is a medium-severity vulnerability in Linux kernel, published on 29 Dec 2024. 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-2024-56744 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2024-56744/ (Markdown: https://insights.sbomify.com/CVE-2024-56744/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56744
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56744
- OSV: https://osv.dev/vulnerability/CVE-2024-56744

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56744/
Summaries are generated and may contain mistakes; the official description above is the record.
