# CVE-2023-53616: jfs: fix invalid free of JFS_IP(ipimap)->i_imap in diUnmount

> A double-free vulnerability in the Linux kernel's JFS filesystem allows local attackers to cause a system crash or potentially execute arbitrary 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:** 4 Oct 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2023-53616, DEBIAN-CVE-2023-53616, GHSA-v852-w8jm-hg43, UBUNTU-CVE-2023-53616

## What is CVE-2023-53616?

CVE-2023-53616 is a high-severity use after free vulnerability in Linux kernel, published on 4 Oct 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:

jfs: fix invalid free of JFS_IP(ipimap)->i_imap in diUnmount

syzbot found an invalid-free in diUnmount:

BUG: KASAN: double-free in slab_free mm/slub.c:3661 [inline]
BUG: KASAN: double-free in __kmem_cache_free+0x71/0x110 mm/slub.c:3674
Free of addr ffff88806f410000 by task syz-executor131/3632

 CPU: 0 PID: 3632 Comm: syz-executor131 Not tainted 6.1.0-rc7-syzkaller-00012-gca57f02295f1 #0
 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
 Call Trace:
  <TASK>
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
  print_address_description+0x74/0x340 mm/kasan/report.c:284
  print_report+0x107/0x1f0 mm/kasan/report.c:395
  kasan_report_invalid_free+0xac/0xd0 mm/kasan/report.c:460
  ____kasan_slab_free+0xfb/0x120
  kasan_slab_free include/linux/kasan.h:177 [inline]
  slab_free_hook mm/slub.c:1724 [inline]
  slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1750
  slab_free mm/slub.c:3661 [inline]
  __kmem_cache_free+0x71/0x110 mm/slub.c:3674
  diUnmount+0xef/0x100 fs/jfs/jfs_imap.c:195
  jfs_umount+0x108/0x370 fs/jfs/jfs_umount.c:63
  jfs_put_super+0x86/0x190 fs/jfs/super.c:194
  generic_shutdown_super+0x130/0x310 fs/super.c:492
  kill_block_super+0x79/0xd0 fs/super.c:1428
  deactivate_locked_super+0xa7/0xf0 fs/super.c:332
  cleanup_mnt+0x494/0x520 fs/namespace.c:1186
  task_work_run+0x243/0x300 kernel/task_work.c:179
  exit_task_work include/linux/task_work.h:38 [inline]
  do_exit+0x664/0x2070 kernel/exit.c:820
  do_group_exit+0x1fd/0x2b0 kernel/exit.c:950
  __do_sys_exit_group kernel/exit.c:961 [inline]
  __se_sys_exit_group kernel/exit.c:959 [inline]
  __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:959
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...]

JFS_IP(ipimap)->i_imap is not setting to NULL after free in diUnmount.
If jfs_remount() free JFS_IP(ipimap)->i_imap but then failed at diMount().
JFS_IP(ipimap)->i_imap will be freed once again.
Fix this problem by setting JFS_IP(ipimap)->i_imap to NULL after free.

Weakness: CWE-415 (Double Free)

## Which versions are affected by CVE-2023-53616?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53616?

Apply the vendor's patch.

## Is CVE-2023-53616 being exploited?

There is no known exploitation of CVE-2023-53616 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-2023-53616 and fix it if it is affected.

What it is: CVE-2023-53616 is a high-severity use after free vulnerability in Linux kernel, published on 4 Oct 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-2023-53616 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-2023-53616/ (Markdown: https://insights.sbomify.com/CVE-2023-53616/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53616
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53616
- OSV: https://osv.dev/vulnerability/CVE-2023-53616

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53616/
Summaries are generated and may contain mistakes; the official description above is the record.