# CVE-2024-56621: scsi: ufs: core: Cancel RTC work during ufshcd_remove()

> A missing cancellation of RTC work during UFS driver removal causes a kernel NULL pointer dereference, leading to a system crash.

- **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:** 27 Dec 2024
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2024-56621, DEBIAN-CVE-2024-56621, GHSA-g3c8-2g4x-qq2h, UBUNTU-CVE-2024-56621

## What is CVE-2024-56621?

CVE-2024-56621 is a medium-severity 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: ufs: core: Cancel RTC work during ufshcd_remove()

Currently, RTC work is only cancelled during __ufshcd_wl_suspend(). When
ufshcd is removed in ufshcd_remove(), RTC work is not cancelled. Due to
this, any further trigger of the RTC work after ufshcd_remove() would
result in a NULL pointer dereference as below:

Unable to handle kernel NULL pointer dereference at virtual address 00000000000002a4
Workqueue: events ufshcd_rtc_work
Call trace:
 _raw_spin_lock_irqsave+0x34/0x8c
 pm_runtime_get_if_active+0x24/0xb4
 ufshcd_rtc_work+0x124/0x19c
 process_scheduled_works+0x18c/0x2d8
 worker_thread+0x144/0x280
 kthread+0x11c/0x128
 ret_from_fork+0x10/0x20

Since RTC work accesses the ufshcd internal structures, it should be cancelled
when ufshcd is removed. So do that in ufshcd_remove(), as per the order in
ufshcd_init().

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2024-56621?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-56621?

Apply the vendor's patch.

## Is CVE-2024-56621 being exploited?

There is no known exploitation of CVE-2024-56621 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-2024-56621 and fix it if it is affected.

What it is: CVE-2024-56621 is a medium-severity 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-2024-56621 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-2024-56621/ (Markdown: https://insights.sbomify.com/CVE-2024-56621/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56621
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56621
- OSV: https://osv.dev/vulnerability/CVE-2024-56621

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56621/
Summaries are generated and may contain mistakes; the official description above is the record.