# CVE-2023-53847: usb-storage: alauda: Fix uninit-value in alauda_check_media()

> An attacker with physical access can trigger an uninitialized memory read in the Linux kernel's Alauda USB storage driver, potentially leaking sensitive data or causing a crash.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 9 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2023-53847, DEBIAN-CVE-2023-53847, GHSA-c2v2-h9q2-p64v, UBUNTU-CVE-2023-53847

## What is CVE-2023-53847?

CVE-2023-53847 is a vulnerability in Linux, published on 9 Dec 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

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

usb-storage: alauda: Fix uninit-value in alauda_check_media()

Syzbot got KMSAN to complain about access to an uninitialized value in
the alauda subdriver of usb-storage:

BUG: KMSAN: uninit-value in alauda_transport+0x462/0x57f0
drivers/usb/storage/alauda.c:1137
CPU: 0 PID: 12279 Comm: usb-storage Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x191/0x1f0 lib/dump_stack.c:113
  kmsan_report+0x13a/0x2b0 mm/kmsan/kmsan_report.c:108
  __msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:250
  alauda_check_media+0x344/0x3310 drivers/usb/storage/alauda.c:460

The problem is that alauda_check_media() doesn't verify that its USB
transfer succeeded before trying to use the received data.  What
should happen if the transfer fails isn't entirely clear, but a
reasonably conservative approach is to pretend that no media is
present.

A similar problem exists in a usb_stor_dbg() call in
alauda_get_media_status().  In this case, when an error occurs the
call is redundant, because usb_stor_ctrl_transfer() already will print
a debugging message.

Finally, unrelated to the uninitialized memory access, is the fact
that alauda_check_media() performs DMA to a buffer on the stack.
Fortunately usb-storage provides a general purpose DMA-able buffer for
uses like this.  We'll use it instead.

## Which versions are affected by CVE-2023-53847?


## How do I fix CVE-2023-53847?

Apply the vendor's patch.

## Is CVE-2023-53847 being exploited?

There is no known exploitation of CVE-2023-53847 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53847 and fix it if it is affected.

What it is: CVE-2023-53847 is a vulnerability in Linux, published on 9 Dec 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-53847 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-2023-53847/ (Markdown: https://insights.sbomify.com/CVE-2023-53847/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53847
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53847
- OSV: https://osv.dev/vulnerability/CVE-2023-53847

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53847/
Summaries are generated and may contain mistakes; the official description above is the record.