{"id":"CVE-2021-47450","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Fix host stage-2 PGD refcount\n\nThe KVM page-table library refcounts the pages of concatenated stage-2\nPGDs individually. However, when running KVM in protected mode, the\nhost's stage-2 PGD is currently managed by EL2 as a single high-order\ncompound page, which can cause the refcount of the tail pages to reach 0\nwhen they shouldn't, hence corrupting the page-table.\n\nFix this by introducing a new hyp_split_page() helper in the EL2 page\nallocator (matching the kernel's split_page() function), and make use of\nit from host_s2_zalloc_pages_exact().","modified":"2026-03-14T11:19:11.718180Z","published":"2024-05-22T07:15:10.143Z","related":["SUSE-SU-2024:2008-1","SUSE-SU-2024:2011-1","SUSE-SU-2024:2019-1","SUSE-SU-2024:2189-1","SUSE-SU-2024:2190-1"],"references":[{"type":"FIX","url":"https://git.kernel.org/stable/c/1d58a17ef54599506d44c45ac95be27273a4d2b1"},{"type":"FIX","url":"https://git.kernel.org/stable/c/b372264c66ef78f2cab44e877fbd765ad6d24c39"}],"affected":[{"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47450.json","unresolved_ranges":[{"events":[{"introduced":"5.13"},{"fixed":"5.14.15"}]},{"events":[{"introduced":"0"},{"last_affected":"5.15-rc1"}]},{"events":[{"introduced":"0"},{"last_affected":"5.15-rc2"}]},{"events":[{"introduced":"0"},{"last_affected":"5.15-rc3"}]},{"events":[{"introduced":"0"},{"last_affected":"5.15-rc4"}]},{"events":[{"introduced":"0"},{"last_affected":"5.15-rc5"}]},{"events":[{"introduced":"0"},{"last_affected":"5.15-rc6"}]}]}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}