PT-2025-18495 · Linux+2 · Linux Kernel+2

Published 2022-11-18 · Updated 2025-05-13 · CVE-2022-49778

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.1.0-rc3+

Description The issue arises from the incorrect handling of file map count for non-leaf pmd/pud in the Linux kernel, specifically when collapsing hugepages. This triggers an unexpected BUG ON() due to the decrease of file map count for a non-leaf pmd. The problem is solved by using pmd leaf() instead of pmd present() in pmd user accessible page() and pud leaf() for pud user accessible page().

Recommendations For Linux kernel versions prior to 6.1.0-rc3+, update to a version that includes the fix for the incorrect file map count handling. As a temporary workaround, consider disabling the collapse huge page() function until a patch is available. Restrict access to the pmd user accessible page() and pud user accessible page() functions to minimize the risk of exploitation.

Exploit

Fix

Assertion Failure

Buffer Overflow

Weakness Enumeration

CWE-617

CWE-120

Related Identifiers

BDU:2026-03717

CVE-2022-49778

RHSA-2025:6966

RHSA-2025_6966

Affected Products

Astra Linux

Linux Kernel

Red Hat

References · 17

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49778.json · Exploit
• https://git.kernel.org/stable/c/2d458046df634088611d44fd77f45465e833ef78 · Patch
• https://bdu.fstec.ru/vul/2026-03717 · Security Note
• https://git.kernel.org/stable/c/5b47348fc0b18a78c96f8474cc90b7525ad1bbfe · Patch
• https://osv.dev/vulnerability/UBUNTU-CVE-2022-49778 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2022-49778 · Security Note
• https://ubuntu.com/security/CVE-2022-49778 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2022-49778 · Security Note
• https://osv.dev/vulnerability/CVE-2022-49778 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2022-49778 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2022-49778 · Vendor Advisory
• https://kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.0.10 · Note
• https://twitter.com/CVEnew/status/1918014654237769850 · Twitter Post
• https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git · Note
• https://git.kernel.org/linus/5b47348fc0b18a78c96f8474cc90b7525ad1bbfe · Note