# CVE-2024-56623: scsi: qla2xxx: Fix use after free on unload

> A use-after-free vulnerability in the qla2xxx SCSI driver causes a system crash during module unload, requiring a kernel patch.

- **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:** 27 Dec 2024
- **Updated:** 11 May 2026
- **Also known as:** AZL-55144, AZL-55237, BELL-CVE-2024-56623, DEBIAN-CVE-2024-56623, GHSA-7437-h333-6p8j, UBUNTU-CVE-2024-56623

## What is CVE-2024-56623?

CVE-2024-56623 is a high-severity use after free vulnerability in Linux kernel, published on 27 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:

scsi: qla2xxx: Fix use after free on unload

System crash is observed with stack trace warning of use after
free. There are 2 signals to tell dpc_thread to terminate (UNLOADING
flag and kthread_stop).

On setting the UNLOADING flag when dpc_thread happens to run at the time
and sees the flag, this causes dpc_thread to exit and clean up
itself. When kthread_stop is called for final cleanup, this causes use
after free.

Remove UNLOADING signal to terminate dpc_thread.  Use the kthread_stop
as the main signal to exit dpc_thread.

[596663.812935] kernel BUG at mm/slub.c:294!
[596663.812950] invalid opcode: 0000 [#1] SMP PTI
[596663.812957] CPU: 13 PID: 1475935 Comm: rmmod Kdump: loaded Tainted: G          IOE    --------- -  - 4.18.0-240.el8.x86_64 #1
[596663.812960] Hardware name: HP ProLiant DL380p Gen8, BIOS P70 08/20/2012
[596663.812974] RIP: 0010:__slab_free+0x17d/0x360

...
[596663.813008] Call Trace:
[596663.813022]  ? __dentry_kill+0x121/0x170
[596663.813030]  ? _cond_resched+0x15/0x30
[596663.813034]  ? _cond_resched+0x15/0x30
[596663.813039]  ? wait_for_completion+0x35/0x190
[596663.813048]  ? try_to_wake_up+0x63/0x540
[596663.813055]  free_task+0x5a/0x60
[596663.813061]  kthread_stop+0xf3/0x100
[596663.813103]  qla2x00_remove_one+0x284/0x440 [qla2xxx]

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-56623?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-56623?

Apply the vendor's patch.

## Is CVE-2024-56623 being exploited?

There is no known exploitation of CVE-2024-56623 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-2024-56623 and fix it if it is affected.

What it is: CVE-2024-56623 is a high-severity use after free vulnerability in Linux kernel, published on 27 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-2024-56623 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-2024-56623/ (Markdown: https://insights.sbomify.com/CVE-2024-56623/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56623
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56623
- OSV: https://osv.dev/vulnerability/CVE-2024-56623

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56623/
Summaries are generated and may contain mistakes; the official description above is the record.