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 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.

• linux linux kernel (>= 2.6.20 < 5.10.239) • linux linux kernel (>= 5.11 < 5.15.186) • linux linux kernel (>= 5.16 < 6.1.142) • linux linux kernel (>= 6.2 < 6.6.95) • linux linux kernel (>= 6.7 < 6.12.35) • linux linux kernel (>= 6.13 < 6.15.4) • debian debian linux 11.0