In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
LoongArch: KVM: Preserve memslot arch flags on KVM_MR_FLAGS_ONLY<\/p>\n
kvm_arch_prepare_memory_region() computes new->arch.flags, i.e. whether
\na memslot is KVM_MEM_HUGEPAGE_CAPABLE or KVM_MEM_HUGEPAGE_INCAPABLE,
\nonly for KVM_MR_CREATE and KVM_MR_MOVE, and returns early for every
\nother change. But the generic code allocates a zeroed memslot for every
\nchange and never copies old->arch, so after a KVM_MR_FLAGS_ONLY update,
\ne.g. toggling KVM_MEM_LOG_DIRTY_PAGES for live migration, the active
\nmemslot has arch.flags == 0.<\/p>\n
With both flags clear, fault_supports_huge_mapping() falls through to
\nthe alignment check on the HVA range alone, which no longer verifies
\nthat the GPA and HVA have the same offset within a PMD. A memslot that
\nwas marked KVM_MEM_HUGEPAGE_INCAPABLE because of a GPA\/HVA offset
\nmismatch can then be mapped with PMD entries on read faults, and since
\nkvm_map_page() aligns the gfn and the pfn independently, the guest ends
\nup accessing the wrong host pages, exactly the “d -> f, e -> g” case
\ndescribed in the comment above the check.<\/p>\n
Carry the arch flags over from the old memslot for KVM_MR_FLAGS_ONLY,
\nas the GPA, HVA and size are guaranteed to be unchanged for that case.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
LoongArch: KVM: Preserve memslot arch flags on KVM_MR_FLAGS_ONLY<\/p>\n
kvm_arch_prepare_memory_region() computes new->arch.flags, i.e. w<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-24595","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/24595","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=24595"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=24595"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=24595"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}