CVE-2024-41055: mm: prevent derefencing NULL ptr in pfn_section_valid()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-29 · updated 2026-06-17
Weakness: CWE-476

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.

Affected products

Linux kernel: from 5.10.219 before 5.10.222; from 5.15.149 before 5.15.163; from 6.1.76 before 6.1.100; from 6.6.15 before 6.6.41; from 6.8 before 6.9.10 — fixed in 5.10.222, 5.15.163, 6.1.100, 6.6.41, 6.9.10

How to fix

Upgrade to a fixed version: Linux kernel 5.10.222, 5.15.163, 6.1.100, 6.6.41. Check the vendor advisory for mitigations.

References

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