CVE-2022-49991

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

mm/hugetlb: avoid corrupting page->mapping in hugetlb_mcopy_atomic_pte

In MCOPY_ATOMIC_CONTINUE case with a non-shared VMA, pages in the page cache are installed in the ptes. But hugepage_add_new_anon_rmap is called for them mistakenly because they're not vm_shared. This will corrupt the page->mapping used by page cache code.

This flaw is rated as a Moderate severity impact for Red Hat Enterprise Linux because exploitation requires a local user to perform specific userfaultfd operations on non-shared HugeTLB mappings, limiting the attack surface to authenticated local processes. A local attacker could leverage this issue to trigger memory corruption within the kernel page cache structures, potentially resulting in system instability, kernel panics, or privilege escalation. Because this vulnerability cannot be triggered remotely and relies on specialized memory management interfaces, the overall blast radius is constrained under standard deployment conditions.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.