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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2024-41055
• https://git.kernel.org/stable/c/0100aeb8a12d51950418e685f879cc80cb8e5982
• https://git.kernel.org/stable/c/797323d1cf92d09b7a017cfec576d9babf99cde7
• https://git.kernel.org/stable/c/82f0b6f041fad768c28b4ad05a683065412c226e
• https://git.kernel.org/stable/c/941e816185661bf2b44b488565d09444ae316509
• https://git.kernel.org/stable/c/adccdf702b4ea913ded5ff512239e382d7473b63
• https://git.kernel.org/stable/c/bc17f2377818dca643a74499c3f5333500c90503