CVE-2026-72173: fs/proc/task_mmu: do not warn on seeing non-migration pmd entry
In the Linux kernel, the following vulnerability has been resolved:
fs/proc/taskmmu: 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):
pagemappmdrangethp() 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
In the Linux kernel, update fs/proc/task_mmu so that pagemap_pmd_range_thp() does not emit a warning when encountering a non-present PMD that is not a migration (i.e., remove the stale migration-only assertion that became false with PMD device-private entries).
Linux kernel (procfs/pagemap) fs/proc/task_mmu: do not warn on seeing non-migration pmd entry = Disable the warning for non-migration PMD entries in pagemap_pmd_range_thp()
Event History
Frequently Asked Questions
What is the severity of CVE-2026-72173?
CVE-2026-72173 has been rated with a severity risk level of 2.
How do I fix CVE-2026-72173?
To fix CVE-2026-72173, update your Linux kernel to the latest version that includes the patch addressing this vulnerability.
What systems are affected by CVE-2026-72173?
CVE-2026-72173 affects the Linux kernel implementations that utilize the fs/proc/task_mmu feature.
What are the implications of CVE-2026-72173?
The implications of CVE-2026-72173 include potential performance concerns due to redundant warnings in the Linux kernel.
Has CVE-2026-72173 been resolved?
Yes, CVE-2026-72173 has been resolved with a patch included in the latest kernel updates.