# CVE-2024-35921: media: mediatek: vcodec: Fix oops when HEVC init fails

> A use-after-free vulnerability in the MediaTek HEVC decoder driver allows local attackers to cause a system crash.

- **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:** 19 May 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2024-35921, DEBIAN-CVE-2024-35921, GHSA-qh4w-v3w8-h422, UBUNTU-CVE-2024-35921

## What is CVE-2024-35921?

CVE-2024-35921 is a high-severity use after free vulnerability in Linux kernel, published on 19 May 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:

media: mediatek: vcodec: Fix oops when HEVC init fails

The stateless HEVC decoder saves the instance pointer in the context
regardless if the initialization worked or not. This caused a use after
free, when the pointer is freed in case of a failure in the deinit
function.
Only store the instance pointer when the initialization was successful,
to solve this issue.

 Hardware name: Acer Tomato (rev3 - 4) board (DT)
 pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : vcodec_vpu_send_msg+0x4c/0x190 [mtk_vcodec_dec]
 lr : vcodec_send_ap_ipi+0x78/0x170 [mtk_vcodec_dec]
 sp : ffff80008750bc20
 x29: ffff80008750bc20 x28: ffff1299f6d70000 x27: 0000000000000000
 x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
 x23: ffff80008750bc98 x22: 000000000000a003 x21: ffffd45c4cfae000
 x20: 0000000000000010 x19: ffff1299fd668310 x18: 000000000000001a
 x17: 000000040044ffff x16: ffffd45cb15dc648 x15: 0000000000000000
 x14: ffff1299c08da1c0 x13: ffffd45cb1f87a10 x12: ffffd45cb2f5fe80
 x11: 0000000000000001 x10: 0000000000001b30 x9 : ffffd45c4d12b488
 x8 : 1fffe25339380d81 x7 : 0000000000000001 x6 : ffff1299c9c06c00
 x5 : 0000000000000132 x4 : 0000000000000000 x3 : 0000000000000000
 x2 : 0000000000000010 x1 : ffff80008750bc98 x0 : 0000000000000000
 Call trace:
  vcodec_vpu_send_msg+0x4c/0x190 [mtk_vcodec_dec]
  vcodec_send_ap_ipi+0x78/0x170 [mtk_vcodec_dec]
  vpu_dec_deinit+0x1c/0x30 [mtk_vcodec_dec]
  vdec_hevc_slice_deinit+0x30/0x98 [mtk_vcodec_dec]
  vdec_if_deinit+0x38/0x68 [mtk_vcodec_dec]
  mtk_vcodec_dec_release+0x20/0x40 [mtk_vcodec_dec]
  fops_vcodec_release+0x64/0x118 [mtk_vcodec_dec]
  v4l2_release+0x7c/0x100
  __fput+0x80/0x2d8
  __fput_sync+0x58/0x70
  __arm64_sys_close+0x40/0x90
  invoke_syscall+0x50/0x128
  el0_svc_common.constprop.0+0x48/0xf0
  do_el0_svc+0x24/0x38
  el0_svc+0x38/0xd8
  el0t_64_sync_handler+0xc0/0xc8
  el0t_64_sync+0x1a8/0x1b0
 Code: d503201f f9401660 b900127f b900227f (f9400400)

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-35921?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-35921?

Apply the vendor's patch.

## Is CVE-2024-35921 being exploited?

There is no known exploitation of CVE-2024-35921 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-2024-35921 and fix it if it is affected.

What it is: CVE-2024-35921 is a high-severity use after free vulnerability in Linux kernel, published on 19 May 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-2024-35921 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-2024-35921/ (Markdown: https://insights.sbomify.com/CVE-2024-35921/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-35921
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-35921
- OSV: https://osv.dev/vulnerability/CVE-2024-35921

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-35921/
Summaries are generated and may contain mistakes; the official description above is the record.