{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64514","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-19T15:36:31.793Z","datePublished":"2026-07-25T08:52:05.878Z","dateUpdated":"2026-08-17T04:57:05.592Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T04:57:05.592Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nuserfaultfd: gate must_wait writability check on pte_present()\n\nuserfaultfd_must_wait() and userfaultfd_huge_must_wait() read the PTE\nwithout taking the page table lock and then apply pte_write() /\nhuge_pte_write() to it.  Those accessors decode bits from the present\nencoding only; on a swap or migration entry they read the offset bits that\nhappen to share the same position and return an undefined result.\n\nThe intent of the check is \"is this fault still WP-blocked?\".  A\nnon-marker swap entry means the page is in transit -- the userfault\ncontext the original fault delivered against is no longer the same, and\nthe swap-in or migration completion path will re-deliver a fresh fault if\nuserspace still needs to handle it.  Worst case under the current code the\ngarbage write bit says \"wait\", and the thread stays asleep until a\nUFFDIO_WAKE that may never arrive.\n\nGate the writability check on pte_present() so the lockless re-check only\ninspects present-PTE bits when the entry is actually present.  The\nnon-present, non-marker case returns \"don't wait\" and lets the fault path\nretry."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/userfaultfd.c"],"versions":[{"version":"369cd2121be440543280b91056de187f625d0dbb","lessThan":"a5700a4c1c9099ac2ac73fe8a09cf059972e0d2f","status":"affected","versionType":"git"},{"version":"369cd2121be440543280b91056de187f625d0dbb","lessThan":"d4026417e8184d13850a0bad4d96ceb6ed9f7152","status":"affected","versionType":"git"},{"version":"369cd2121be440543280b91056de187f625d0dbb","lessThan":"29e6f952c5fb7dc1d6b90fe5b7f36063d44ddae0","status":"affected","versionType":"git"},{"version":"369cd2121be440543280b91056de187f625d0dbb","lessThan":"5f4dbdb0a87596214076b20b94f2b71b522170b3","status":"affected","versionType":"git"},{"version":"369cd2121be440543280b91056de187f625d0dbb","lessThan":"a6e9a4939e359599701b1da351e84f72e021443a","status":"affected","versionType":"git"},{"version":"369cd2121be440543280b91056de187f625d0dbb","lessThan":"60d696a037eeeedfb57756dfe7ec08a1587c8631","status":"affected","versionType":"git"},{"version":"369cd2121be440543280b91056de187f625d0dbb","lessThan":"710183888174639a15fcec16cd1af766b8480bb7","status":"affected","versionType":"git"},{"version":"369cd2121be440543280b91056de187f625d0dbb","lessThan":"8e80af52db652fbc41320eee45a4f73bc029faf2","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/userfaultfd.c"],"versions":[{"version":"4.11","status":"affected"},{"version":"0","lessThan":"4.11","status":"unaffected","versionType":"semver"},{"version":"5.10.261","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.212","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.178","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.145","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.96","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.39","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.4","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"5.10.261"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.11","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/a5700a4c1c9099ac2ac73fe8a09cf059972e0d2f"},{"url":"https://git.kernel.org/stable/c/d4026417e8184d13850a0bad4d96ceb6ed9f7152"},{"url":"https://git.kernel.org/stable/c/29e6f952c5fb7dc1d6b90fe5b7f36063d44ddae0"},{"url":"https://git.kernel.org/stable/c/5f4dbdb0a87596214076b20b94f2b71b522170b3"},{"url":"https://git.kernel.org/stable/c/a6e9a4939e359599701b1da351e84f72e021443a"},{"url":"https://git.kernel.org/stable/c/60d696a037eeeedfb57756dfe7ec08a1587c8631"},{"url":"https://git.kernel.org/stable/c/710183888174639a15fcec16cd1af766b8480bb7"},{"url":"https://git.kernel.org/stable/c/8e80af52db652fbc41320eee45a4f73bc029faf2"}],"title":"userfaultfd: gate must_wait writability check on pte_present()","x_generator":{"engine":"bippy-1.2.0"}}}}