CVE-2022-49210

/// Technical 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"

/// 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