Updated: 2025-02-27 03:18:02.744466
Description:
In the Linux kernel, the following vulnerability has been resolved: mm: clear uffd-wp PTE/PMD state on mremap() When mremap()ing a memory region previously registered with userfaultfd as write-protected but without UFFD_FEATURE_EVENT_REMAP, an inconsistency in flag clearing leads to a mismatch between the vma flags (which have uffd-wp cleared) and the pte/pmd flags (which do not have uffd-wp cleared). This mismatch causes a subsequent mprotect(PROT_WRITE) to trigger a warning in page_table_check_pte_flags() due to setting the pte to writable while uffd-wp is still set. Fix this by always explicitly clearing the uffd-wp pte/pmd flags on any such mremap() so that the values are consistent with the existing clearing of VM_UFFD_WP. Be careful to clear the logical flag regardless of its physical form; a PTE bit, a swap PTE bit, or a PTE marker. Cover PTE, huge PMD and hugetlb paths.
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | 0 | |
| CVSS Version 3.x | MEDIUM | 5.5 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| AlmaLinux 9.2 ESU | kernel | 5.14.0 | 5.5 | MEDIUM | Ignored | 2025-03-03 21:59:08 | ||
| AlmaLinux 9.6 ESU | kernel | 5.14.0 | 5.5 | MEDIUM | Ignored | 2025-07-05 02:18:12 |