CVE-2025-38681

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

mm/ptdump: take the memory hotplug lock inside ptdump_walk_pgd()

Memory hot remove unmaps and tears down various kernel page table regions

as required. The ptdump code can race with concurrent modifications of

the kernel page tables. When leaf entries are modified concurrently, the

dump code may log stale or inconsistent information for a VA range, but

this is otherwise not harmful.

But when intermediate levels of kernel page table are freed, the dump code

will continue to use memory that has been freed and potentially

reallocated for another purpose. In such cases, the ptdump code may

dereference bogus addresses, leading to a number of potential problems.

To avoid the above mentioned race condition, platforms such as arm64,

riscv and s390 take memory hotplug lock, while dumping kernel page table

via the sysfs interface /sys/kernel/debug/kernel_page_tables.

Similar race condition exists while checking for pages

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References