CVE-2026-72173

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

fs/proc/task_mmu: do not warn on seeing non-migration pmd entry

Patch series "mm/hmm: A fix and a selftest", v3.

Patch 1 fixes a stale warning present from the time when only migration softleaf entries were supported at the PMD level.

Patch 2 adds some code into hmm-tests.c which exercises the pagemap path for PMD device-private entries.

This patch (of 2):

pagemap_pmd_range_thp() warns if a non-present PMD is not a migration entry. This became false once device-private entries at the PMD level were added.

Therefore, remove the stale migration-only assertion.