CVE-2026-89961 powerpc/mm: fix wrong addr_pfn tracking in compound vmemmap population

In the Linux kernel, the following vulnerability has been resolved: powerpc/mm: fix wrong addrpfn tracking in compound vmemmap population vmemmappopulatecompoundpages uses addrpfn to determine the PFN offset within a compound page and to decide whether the current vmemmap slot should be populated...

EUVD-2026-80561

In the Linux kernel, the following vulnerability has been resolved: powerpc/mm: fix wrong addrpfn tracking in compound vmemmap population vmemmappopulatecompoundpages uses addrpfn to determine the PFN offset within a compound page and to decide whether the current vmemmap slot should be populated...

CVE-2026-89961

CVE-2026-89961 affects the Linux kernel 's powerpc/mm subsystem, specifically the vmemmap_populate_compound_pages() function. The root cause is a mismatch in how addr_pfn is advanced relative to the loop's addr variable in vmemmap address space. Because each PAGE_SIZE step in addr spans PAGE_SIZE...