# CVE-2023-53468: ubifs: Fix memory leak in alloc_wbufs()

> A memory leak in the Linux kernel's UBIFS filesystem allows attackers to cause a denial of service by exhausting system memory during mount operations.

- **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:** 1 Oct 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53468, DEBIAN-CVE-2023-53468, GHSA-rwqr-mq87-5p2c, UBUNTU-CVE-2023-53468

## What is CVE-2023-53468?

CVE-2023-53468 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 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:

ubifs: Fix memory leak in alloc_wbufs()

kmemleak reported a sequence of memory leaks, and show them as following:

  unreferenced object 0xffff8881575f8400 (size 1024):
    comm "mount", pid 19625, jiffies 4297119604 (age 20.383s)
    hex dump (first 32 bytes):
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
      00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    backtrace:
      [<ffffffff8176cecd>] __kmalloc+0x4d/0x150
      [<ffffffffa0406b2b>] ubifs_mount+0x307b/0x7170 [ubifs]
      [<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0
      [<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230
      [<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0
      [<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270
      [<ffffffff83c14295>] do_syscall_64+0x35/0x80
      [<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

  unreferenced object 0xffff8881798a6e00 (size 512):
    comm "mount", pid 19677, jiffies 4297121912 (age 37.816s)
    hex dump (first 32 bytes):
      6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
      6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
    backtrace:
      [<ffffffff8176cecd>] __kmalloc+0x4d/0x150
      [<ffffffffa0418342>] ubifs_wbuf_init+0x52/0x480 [ubifs]
      [<ffffffffa0406ca5>] ubifs_mount+0x31f5/0x7170 [ubifs]
      [<ffffffff819fa8fd>] legacy_get_tree+0xed/0x1d0
      [<ffffffff81936f2d>] vfs_get_tree+0x7d/0x230
      [<ffffffff819b2bd4>] path_mount+0xdd4/0x17b0
      [<ffffffff819b37aa>] __x64_sys_mount+0x1fa/0x270
      [<ffffffff83c14295>] do_syscall_64+0x35/0x80
      [<ffffffff83e0006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

The problem is that the ubifs_wbuf_init() returns an error in the
loop which in the alloc_wbufs(), then the wbuf->buf and wbuf->inodes
that were successfully alloced before are not freed.

Fix it by adding error hanging path in alloc_wbufs() which frees
the memory alloced before when ubifs_wbuf_init() returns an error.

Weakness: CWE-401 (Missing Release of Memory after Effective Lifetime)

## Which versions are affected by CVE-2023-53468?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53468?

Apply the vendor's patch.

## Is CVE-2023-53468 being exploited?

There is no known exploitation of CVE-2023-53468 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-2023-53468 and fix it if it is affected.

What it is: CVE-2023-53468 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 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-2023-53468 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-2023-53468/ (Markdown: https://insights.sbomify.com/CVE-2023-53468/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53468
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53468
- OSV: https://osv.dev/vulnerability/CVE-2023-53468

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53468/
Summaries are generated and may contain mistakes; the official description above is the record.
