CVE-2026-64561

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> KVM: x86: Check for invalid/obsolete root *after* making MMU pages available<br /> <br /> Check for a "stale" page fault, i.e. for an invalid and/or obsolete root,<br /> after making MMU pages available for the shadow MMU. If reclaiming shadow<br /> pages zaps an in-use root, i.e. marks it invalid, then KVM will attempt to<br /> map memory into an invalid root. On its own, populating an invalid root is<br /> "fine", but because child shadow pages inherit their parent&amp;#39;s role, any<br /> children created during the map/fetch will be created as invalid pages,<br /> thus violating KVM&amp;#39;s invariant that invalid pages are never on the list of<br /> active MMU pages.<br /> <br /> Note, the underlying flaw has existed since KVM first started tracking<br /> invalid roots in 2008 (commit 2e53d63acba7, "KVM: MMU: ignore zapped root<br /> pagetables"), but the true badness only came along in 2020 (Linux 5.9)<br /> with the invariant that invalid shadow pages can&amp;#39;t be on the list of<br /> active pages.<br /> <br /> Note #2, inheriting role.invalid when creating child shadow pages is also<br /> far from ideal; that flaw will be addressed separately.