CVE-2022-49828

/// Technical description

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

hugetlbfs: don't delete error page from pagecache

This change is very similar to the change that was made for shmem [1], and

it solves the same problem but for HugeTLBFS instead.

Currently, when poison is found in a HugeTLB page, the page is removed

from the page cache. That means that attempting to map or read that

hugepage in the future will result in a new hugepage being allocated

instead of notifying the user that the page was poisoned. As [1] states,

this is effectively memory corruption.

The fix is to leave the page in the page cache. If the user attempts to

use a poisoned HugeTLB page with a syscall, the syscall will fail with

EIO, the same error code that shmem uses. For attempts to map the page,

the thread will get a BUS_MCEERR_AR SIGBUS.

[1]: commit a76054266661 ("mm: shmem: don't truncate page if memory failure happens")

/// 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