{"id":"CVE-2026-93218","summary":"mm/huge_memory: skip device-private PMDs in madvise_free_huge_pmd","details":"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().","modified":"2026-09-25T03:48:52.207290442Z","published":"2026-09-24T15:10:41.370Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93218.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5e3026bf736498115884d6c7bd0308ba29e0474c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ce579dcf730ce5ed8043a5eeea18a3e6706a97e5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93218.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-93218"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"368076f52ebeecd33e10a9f80905d7508b6b6149"},{"fixed":"5e3026bf736498115884d6c7bd0308ba29e0474c"},{"fixed":"ce579dcf730ce5ed8043a5eeea18a3e6706a97e5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93218.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-93218.json"}}],"schema_version":"1.9.0"}