CVE-2026-31397

CVE-2026-31397 relates to the Linux kernel memory management path mm/huge_memory move_pages_huge_pmd(), where the huge zero page branch used a NULL src_folio, causing a bogus PFN (or NULL dereference on some memory models) when constructing PMDs. The fix uses page_folio(src_page) to obtain a vali...

kernel: mm: clear uffd-wp PTE/PMD state on mremap()

In the Linux kernel, the following vulnerability has been resolved: mm: clear uffd-wp PTE/PMD state on mremap When mremaping a memory region previously registered with userfaultfd as write-protected but without UFFDFEATUREEVENTREMAP, an inconsistency in flag clearing leads to a mismatch between t...

kernel: mm/hugetlb: fix PTE marker handling in hugetlb_change_protection()

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb: fix PTE marker handling in hugetlbchangeprotection Patch series "mm/hugetlb: uffd-wp fixes for hugetlbchangeprotection". Playing with virtio-mem and background snapshots using uffd-wp on hugetlb in QEMU, I managed to...