PT-2025-38551 · Linux +1 · Linux Kernel +1

Published 2025-09-19 · Updated 2025-09-20 · CVE-2025-39844

Positive Technologies · (AI Summary)

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A flaw exists in the Linux kernel related to page table synchronization during vmemmap initialization. Specifically, the optimized path within

vmemmap populate compound pages()

skips synchronization of top-level page tables, potentially leading to kernel panics when accessing the vmemmap area before the corresponding top-level entries are synchronized. This issue arises from relying on each architecture to manually handle page table synchronization, which is prone to errors and omissions. The solution involves introducing

pgd populate kernel()

and

p4d populate kernel()

to explicitly perform synchronization when installing top-level entries, leveraging existing mechanisms used by vmalloc and ioremap.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Related Identifiers

CVE-2025-39844

ECHO-131D-5CA1-B72E

Affected Products

Debian

Linux Kernel

References · 19

• https://security-tracker.debian.org/tracker/CVE-2025-39844 · Vendor Advisory
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-39844 · Security Note
• https://ubuntu.com/security/CVE-2025-39844 · Vendor Advisory
• https://osv.dev/vulnerability/BELL-CVE-2025-39844 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2025-39844 · Security Note
• https://security-tracker.debian.org/tracker/source-package/linux · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2025-39844 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-39844 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2025-39844 · Vendor Advisory
• https://git.kernel.org/stable/c/4f7537772011fad832f83d6848f8eab282545bef · Note
• https://git.kernel.org/stable/c/6797a8b3f71b2cb558b8771a03450dc3e004e453 · Note
• https://git.kernel.org/stable/c/469f9d22751472b81eaaf8a27fcdb5a70741c342 · Note
• https://git.kernel.org/linus/7cc183f2e67d19b03ee5c13a6664b8c6cc37ff9d · Note
• https://git.kernel.org/stable/c/eceb44e1f94bd641b2a4e8c09b64c797c4eabc15 · Note
• https://git.kernel.org/stable/c/732e62212f49d549c91071b4da7942ee3058f7a2 · Note