{"id":"CVE-2026-74600","state":"PUBLISHED","title":"mm/page_table_check: skip special zero mappings","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_table_check: skip special zero mappings\n\npage_table_check_set() and page_table_check_clear() account mappings based\non PageAnon().  Shared zero-page PTEs and huge zero PMDs are special\nmappings, but page_table_check can still account them as file-backed\npages.\n\nAn unprivileged process can populate enough zero mappings to overflow\nfile_map_count and hit the existing BUG_ON().  The PTE path can do this\nwith the shared zero page, and the PMD path can do the same with huge zero\nmappings.\n\nSkip special zero mappings in the user page-table accounting paths.  Keep\nthe PTE-side pte_special() check, and identify huge zero PMDs from the\nmapped folio instead of pmd_special().  That covers architectures where\npmd_special() is a no-op without adding huge_zero_pfn checks to the\ngeneric counter helpers.","publishedAt":"2026-08-22T15:31:49.334Z","updatedAt":"2026-10-30T12:30:13.139Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"084b031a1cc13b1d50b9660baace0b7eba52bebe","versionType":"git"},{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"f6cf9832e677ec07b1675782bd2bad472cfd3cdc","versionType":"git"},{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"51e16e5adadaa78b56f31a1cb02eb7267787625e","versionType":"git"},{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"7755be923e325dc300f4b0c3e1ad7e91b28b3cb9","versionType":"git"},{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"b726eb3c94d23e09da0e0f46b0fa09fb2b5d99cc","versionType":"git"},{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"8db4bab826ccc9ec10fa41736a48031cd338d392","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/page_table_check.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.46","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/page_table_check.c"]}],"references":["https://git.kernel.org/stable/c/084b031a1cc13b1d50b9660baace0b7eba52bebe","https://git.kernel.org/stable/c/f6cf9832e677ec07b1675782bd2bad472cfd3cdc","https://git.kernel.org/stable/c/51e16e5adadaa78b56f31a1cb02eb7267787625e","https://git.kernel.org/stable/c/7755be923e325dc300f4b0c3e1ad7e91b28b3cb9","https://git.kernel.org/stable/c/b726eb3c94d23e09da0e0f46b0fa09fb2b5d99cc","https://git.kernel.org/stable/c/8db4bab826ccc9ec10fa41736a48031cd338d392"],"weaknesses":[],"ingestedAt":"2026-10-30T12:48:04.825Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74600.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74600","state":"PUBLISHED","datePublished":"2026-08-22T15:31:49.334Z","dateUpdated":"2026-10-30T12:30:13.139Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.919Z"},"containers":{"cna":{"title":"mm/page_table_check: skip special zero mappings","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/page_table_check: skip special zero mappings\n\npage_table_check_set() and page_table_check_clear() account mappings based\non PageAnon().  Shared zero-page PTEs and huge zero PMDs are special\nmappings, but page_table_check can still account them as file-backed\npages.\n\nAn unprivileged process can populate enough zero mappings to overflow\nfile_map_count and hit the existing BUG_ON().  The PTE path can do this\nwith the shared zero page, and the PMD path can do the same with huge zero\nmappings.\n\nSkip special zero mappings in the user page-table accounting paths.  Keep\nthe PTE-side pte_special() check, and identify huge zero PMDs from the\nmapped folio instead of pmd_special().  That covers architectures where\npmd_special() is a no-op without adding huge_zero_pfn checks to the\ngeneric counter helpers."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"084b031a1cc13b1d50b9660baace0b7eba52bebe","versionType":"git"},{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"f6cf9832e677ec07b1675782bd2bad472cfd3cdc","versionType":"git"},{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"51e16e5adadaa78b56f31a1cb02eb7267787625e","versionType":"git"},{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"7755be923e325dc300f4b0c3e1ad7e91b28b3cb9","versionType":"git"},{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"b726eb3c94d23e09da0e0f46b0fa09fb2b5d99cc","versionType":"git"},{"version":"df4e817b710809425d899340dbfa8504a3ca4ba5","status":"affected","lessThan":"8db4bab826ccc9ec10fa41736a48031cd338d392","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/page_table_check.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.46","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/page_table_check.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/084b031a1cc13b1d50b9660baace0b7eba52bebe"},{"url":"https://git.kernel.org/stable/c/f6cf9832e677ec07b1675782bd2bad472cfd3cdc"},{"url":"https://git.kernel.org/stable/c/51e16e5adadaa78b56f31a1cb02eb7267787625e"},{"url":"https://git.kernel.org/stable/c/7755be923e325dc300f4b0c3e1ad7e91b28b3cb9"},{"url":"https://git.kernel.org/stable/c/b726eb3c94d23e09da0e0f46b0fa09fb2b5d99cc"},{"url":"https://git.kernel.org/stable/c/8db4bab826ccc9ec10fa41736a48031cd338d392"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:30:13.139Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.18.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}