CVE-2026-72174

Technical Description

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

fs/proc/task_mmu: fix hugetlb self-deadlock in pagemap_scan_pte_hole()

A PAGEMAP_SCAN ioctl requesting PM_SCAN_WP_MATCHING on a hugetlb VMA hangs

the calling thread, unkillably, as soon as the scan reaches an unpopulated

part of the range:

do_pagemap_scan()

walk_page_range()

walk_hugetlb_range()

hugetlb_vma_lock_read() # take the vma lock for read ...

pagemap_scan_pte_hole() # ... ->pte_hole() for a hole

uffd_wp_range()

change_protection()

hugetlb_change_protection()

hugetlb_vma_lock_write() # ... and block taking it for write

walk_hugetlb_range() holds the hugetlb vma lock for read across the whole

walk. A present entry goes to ->hugetlb_entry(); an unpopulated one goes

to ->pte_hole(), i.e. pagemap_scan_pte_hole(). To write-protect the hole

that handler calls uffd_wp_range(), which on a hugetlb VMA reaches

huge

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