In the Linux kernel, the following vulnerability has been resolved: mm/userfaultfd: reset ptes when close() for wr-protected ones Userfaultfd unregister includes a step to remove wr-protect bits from all the relevant pgtable entries, but that only covered an explicit UFFDIO_UNREGISTER ioctl, not a close() on the userfaultfd itself. Cover that too. This fixes a WARN trace. The only user visible side effect is the user can observe leftover wr-protect bits even if the user close()ed on an userfaultfd when releasing the last reference of it. However hopefully that should be harmless, and nothing bad should happen even if so. This change is now more important after the recent page-table-check patch we merged in mm-unstable (446dd9ad37d0 ("mm/page_table_check: support userfault wr-protect entries")), as we'll do sanity check on uffd-wp bits without vma context. So it's better if we can 100% guarantee no uffd-wp bit leftovers, to make sure each report will be valid.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-05-30T15:28:52.119Z

Updated: 2024-08-02T03:43:49.857Z

Reserved: 2024-05-30T15:25:07.064Z

Link: CVE-2024-36881

cve-icon Vulnrichment

Updated: 2024-08-02T03:43:49.857Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-05-30T16:15:11.723

Modified: 2024-05-30T18:18:58.870

Link: CVE-2024-36881

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-05-30T00:00:00Z

Links: CVE-2024-36881 - Bugzilla