NetSight
high7.8

CVE-2025-38085

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race huge_pmd_unshare() drops a reference on…

Impact

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race huge_pmd_unshare() drops a reference on a page table that may have previously been shared across processes, potentially turning it into a normal page table used in another process in which unrelated VMAs can afterwards be installed. If this happens in the middle of a concurrent gup_fast(), gup_fast() could end up walking the page tables of another process. While I don't see any way in which that immediately leads to kernel memory corruption, it is really weird and unexpected. Fix it with an explicit broadcast IPI through tlb_remove_table_sync_one(), just like we do in khugepaged when removing page tables for a THP collapse.

Affected products

VendorProductAffected versions
LinuxLinux Kernel
from 2.6.20 before 5.10.239
from 5.11 before 5.15.186
from 5.16 before 6.1.142
from 6.2 before 6.6.95
from 6.7 before 6.12.35
from 6.13 before 6.15.4
DebianDebian Linux
Version 11.0

Weakness classification

References