{"id":"CVE-2026-93217","state":"PUBLISHED","title":"mm/madvise: skip device-private PMDs in cold and pageout walks","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/madvise: skip device-private PMDs in cold and pageout walks\n\nmadvise_cold_or_pageout_pte_range() takes pmd_trans_huge_lock(), whose\npmd_is_huge() check returns true for a device-private PMD.  The subsequent\n!pmd_present() branch has a VM_BUG_ON() asserting migration is the only\nallowed non-present case; a device-private PMD trips it.\n\nSkip device-private PMDs in that non-present branch and continue to\nhuge_unlock before calling pmd_folio().  Downgrade the check to\nVM_WARN_ON_ONCE() so an unexpected PMD softleaf logs a warning rather than\npanicking.  Drop the thp_migration_supported() guard: it expands to\nIS_ENABLED(CONFIG_ARCH_SUPPORTS_PMD_SOFTLEAF), and both\npmd_is_migration_entry() and pmd_is_device_private_entry() already return\nfalse when that config is not selected, so the guard suppresses only the\ncase where the warning would already be silent.\n\nPotential trigger: an HMM-based GPU driver races with\nmadvise(MADV_COLD)/MADV_PAGEOUT: pmd_trans_huge(*pmd) reads true, then\nmigrate_vma_pages() flips the PMD to a device-private entry before the PMD\nlock is acquired.","publishedAt":"2026-09-24T15:10:40.487Z","updatedAt":"2026-10-19T09:07:29.053Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"368076f52ebeecd33e10a9f80905d7508b6b6149","status":"affected","lessThan":"5c0d7b658cda62cd17cb3652783386d5608030ef","versionType":"git"},{"version":"368076f52ebeecd33e10a9f80905d7508b6b6149","status":"affected","lessThan":"d4b76d0b03cb49611312ecc4bcfb55ccdf0843e2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/madvise.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/madvise.c"]}],"references":["https://git.kernel.org/stable/c/5c0d7b658cda62cd17cb3652783386d5608030ef","https://git.kernel.org/stable/c/d4b76d0b03cb49611312ecc4bcfb55ccdf0843e2"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/93xxx/CVE-2026-93217.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-93217","state":"PUBLISHED","datePublished":"2026-09-24T15:10:40.487Z","dateUpdated":"2026-10-19T09:07:29.053Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-17T16:02:15.094Z"},"containers":{"cna":{"title":"mm/madvise: skip device-private PMDs in cold and pageout walks","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/madvise: skip device-private PMDs in cold and pageout walks\n\nmadvise_cold_or_pageout_pte_range() takes pmd_trans_huge_lock(), whose\npmd_is_huge() check returns true for a device-private PMD.  The subsequent\n!pmd_present() branch has a VM_BUG_ON() asserting migration is the only\nallowed non-present case; a device-private PMD trips it.\n\nSkip device-private PMDs in that non-present branch and continue to\nhuge_unlock before calling pmd_folio().  Downgrade the check to\nVM_WARN_ON_ONCE() so an unexpected PMD softleaf logs a warning rather than\npanicking.  Drop the thp_migration_supported() guard: it expands to\nIS_ENABLED(CONFIG_ARCH_SUPPORTS_PMD_SOFTLEAF), and both\npmd_is_migration_entry() and pmd_is_device_private_entry() already return\nfalse when that config is not selected, so the guard suppresses only the\ncase where the warning would already be silent.\n\nPotential trigger: an HMM-based GPU driver races with\nmadvise(MADV_COLD)/MADV_PAGEOUT: pmd_trans_huge(*pmd) reads true, then\nmigrate_vma_pages() flips the PMD to a device-private entry before the PMD\nlock is acquired."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"368076f52ebeecd33e10a9f80905d7508b6b6149","status":"affected","lessThan":"5c0d7b658cda62cd17cb3652783386d5608030ef","versionType":"git"},{"version":"368076f52ebeecd33e10a9f80905d7508b6b6149","status":"affected","lessThan":"d4b76d0b03cb49611312ecc4bcfb55ccdf0843e2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/madvise.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.19","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.19","versionType":"semver"},{"version":"7.2.4","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/madvise.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/5c0d7b658cda62cd17cb3652783386d5608030ef"},{"url":"https://git.kernel.org/stable/c/d4b76d0b03cb49611312ecc4bcfb55ccdf0843e2"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:07:29.053Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}