{"id":"CVE-2026-93218","state":"PUBLISHED","title":"mm/huge_memory: skip device-private PMDs in madvise_free_huge_pmd","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/huge_memory: skip device-private PMDs in madvise_free_huge_pmd\n\nmadvise_free_pte_range() checks pmd_trans_huge(*pmd) unlocked, then\nmadvise_free_huge_pmd() takes pmd_trans_huge_lock().  pmd_is_huge()\nreturns true for a device-private PMD, so orig_pmd can be device-private\nand enter the !pmd_present() branch.\n\nSkip device-private PMDs in that non-present branch and continue to out\nbefore calling pmd_folio().  Downgrade the check to VM_WARN_ON_ONCE() so\nan unexpected PMD softleaf logs a warning rather than panicking.  Drop the\nthp_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 madvise(MADV_FREE):\nmigrate_vma_pages() flips the PMD to a device-private entry between the\ncaller's pmd_trans_huge() check and the callee's pmd_trans_huge_lock().","publishedAt":"2026-09-24T15:10:41.370Z","updatedAt":"2026-10-19T09:07:29.994Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"368076f52ebeecd33e10a9f80905d7508b6b6149","status":"affected","lessThan":"5e3026bf736498115884d6c7bd0308ba29e0474c","versionType":"git"},{"version":"368076f52ebeecd33e10a9f80905d7508b6b6149","status":"affected","lessThan":"ce579dcf730ce5ed8043a5eeea18a3e6706a97e5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/huge_memory.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/huge_memory.c"]}],"references":["https://git.kernel.org/stable/c/5e3026bf736498115884d6c7bd0308ba29e0474c","https://git.kernel.org/stable/c/ce579dcf730ce5ed8043a5eeea18a3e6706a97e5"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/93xxx/CVE-2026-93218.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-93218","state":"PUBLISHED","datePublished":"2026-09-24T15:10:41.370Z","dateUpdated":"2026-10-19T09:07:29.994Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-17T16:02:15.094Z"},"containers":{"cna":{"title":"mm/huge_memory: skip device-private PMDs in madvise_free_huge_pmd","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/huge_memory: skip device-private PMDs in madvise_free_huge_pmd\n\nmadvise_free_pte_range() checks pmd_trans_huge(*pmd) unlocked, then\nmadvise_free_huge_pmd() takes pmd_trans_huge_lock().  pmd_is_huge()\nreturns true for a device-private PMD, so orig_pmd can be device-private\nand enter the !pmd_present() branch.\n\nSkip device-private PMDs in that non-present branch and continue to out\nbefore calling pmd_folio().  Downgrade the check to VM_WARN_ON_ONCE() so\nan unexpected PMD softleaf logs a warning rather than panicking.  Drop the\nthp_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 madvise(MADV_FREE):\nmigrate_vma_pages() flips the PMD to a device-private entry between the\ncaller's pmd_trans_huge() check and the callee's pmd_trans_huge_lock()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"368076f52ebeecd33e10a9f80905d7508b6b6149","status":"affected","lessThan":"5e3026bf736498115884d6c7bd0308ba29e0474c","versionType":"git"},{"version":"368076f52ebeecd33e10a9f80905d7508b6b6149","status":"affected","lessThan":"ce579dcf730ce5ed8043a5eeea18a3e6706a97e5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/huge_memory.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/huge_memory.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/5e3026bf736498115884d6c7bd0308ba29e0474c"},{"url":"https://git.kernel.org/stable/c/ce579dcf730ce5ed8043a5eeea18a3e6706a97e5"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:07:29.994Z"},"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"}}}}}