CVE-2022-49210: MIPS: pgalloc: fix memory leak caused by pgd_free()

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: 2025-02-26 · updated 2026-06-17
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: MIPS: pgalloc: fix memory leak caused by pgd_free() pgd page is freed by generic implementation pgd_free() since commit f9cb654cb550 ("asm-generic: pgalloc: provide generic pgd_free()"), however, there are scenarios that the system uses more than one page as the pgd table, in such cases the generic implementation pgd_free() won't be applicable anymore. For example, when PAGE_SIZE_4KB is enabled and MIPS_VA_BITS_48 is not enabled in a 64bit system, the macro "PGD_ORDER" will be set as "1", which will cause allocating two pages as the pgd table. Well, at the same time, the generic implementation pgd_free() just free one pgd page, which will result in the memory leak. The memory leak can be easily detected by executing shell command: "while true; do ls > /dev/null; grep MemFree /proc/meminfo; done"

Affected products

Linux kernel: from 5.9 before 5.10.110; from 5.11 before 5.15.33; from 5.16 before 5.16.19; from 5.17 before 5.17.2 — fixed in 5.10.110, 5.15.33, 5.16.19, 5.17.2

How to fix

Upgrade to a fixed version: Linux kernel 5.10.110, 5.15.33, 5.16.19, 5.17.2. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2022-49210 or the next vulnerability affects your stack