{"id":"CVE-2026-52936","state":"PUBLISHED","title":"crypto: jitterentropy - replace long-held spinlock with mutex","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: jitterentropy - replace long-held spinlock with mutex\n\njent_kcapi_random() serializes the shared jitterentropy state, but it\ncurrently holds a spinlock across the jent_read_entropy() call. That\npath performs expensive jitter collection and SHA3 conditioning, so\nparallel readers can trigger stalls as contending waiters spin for\nthe same lock.\n\nTo prevent non-preemptible lock hold, replace rng->jent_lock with a\nmutex so contended readers sleep instead of spinning on a shared lock\nheld across expensive entropy generation.","publishedAt":"2026-06-24T07:14:26.649Z","updatedAt":"2026-10-30T12:26:19.497Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"21de77d06f6b540e870e64ef5ff56be4eb8ba08f","versionType":"git"},{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"18216b8ab6904753eaf31baf453cb02ecd202ba4","versionType":"git"},{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"4c03e6eb98443dc4d6d422a9780034a5b75376b4","versionType":"git"},{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"ff734dbd9e2432601a6dcd167cfb0bf8a36d1880","versionType":"git"},{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"ec427dc5286da1ed08f2d510e2147a7581b0cb02","versionType":"git"},{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"01d798e9feb30212952d4e992801ba6bd6a82351","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["crypto/jitterentropy-kcapi.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.2","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["crypto/jitterentropy-kcapi.c"]}],"references":["https://git.kernel.org/stable/c/21de77d06f6b540e870e64ef5ff56be4eb8ba08f","https://git.kernel.org/stable/c/18216b8ab6904753eaf31baf453cb02ecd202ba4","https://git.kernel.org/stable/c/4c03e6eb98443dc4d6d422a9780034a5b75376b4","https://git.kernel.org/stable/c/ff734dbd9e2432601a6dcd167cfb0bf8a36d1880","https://git.kernel.org/stable/c/ec427dc5286da1ed08f2d510e2147a7581b0cb02","https://git.kernel.org/stable/c/01d798e9feb30212952d4e992801ba6bd6a82351"],"weaknesses":[],"ingestedAt":"2026-10-30T12:44:04.813Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/52xxx/CVE-2026-52936.json","commit":"db8103c5921aac81d5d90efcf3745980dafabf49","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-52936","state":"PUBLISHED","datePublished":"2026-06-24T07:14:26.649Z","dateUpdated":"2026-10-30T12:26:19.497Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.370Z"},"containers":{"cna":{"title":"crypto: jitterentropy - replace long-held spinlock with mutex","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: jitterentropy - replace long-held spinlock with mutex\n\njent_kcapi_random() serializes the shared jitterentropy state, but it\ncurrently holds a spinlock across the jent_read_entropy() call. That\npath performs expensive jitter collection and SHA3 conditioning, so\nparallel readers can trigger stalls as contending waiters spin for\nthe same lock.\n\nTo prevent non-preemptible lock hold, replace rng->jent_lock with a\nmutex so contended readers sleep instead of spinning on a shared lock\nheld across expensive entropy generation."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"21de77d06f6b540e870e64ef5ff56be4eb8ba08f","versionType":"git"},{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"18216b8ab6904753eaf31baf453cb02ecd202ba4","versionType":"git"},{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"4c03e6eb98443dc4d6d422a9780034a5b75376b4","versionType":"git"},{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"ff734dbd9e2432601a6dcd167cfb0bf8a36d1880","versionType":"git"},{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"ec427dc5286da1ed08f2d510e2147a7581b0cb02","versionType":"git"},{"version":"bb5530e4082446aac3a3d69780cd4dbfa4520013","status":"affected","lessThan":"01d798e9feb30212952d4e992801ba6bd6a82351","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["crypto/jitterentropy-kcapi.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.2","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["crypto/jitterentropy-kcapi.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/21de77d06f6b540e870e64ef5ff56be4eb8ba08f"},{"url":"https://git.kernel.org/stable/c/18216b8ab6904753eaf31baf453cb02ecd202ba4"},{"url":"https://git.kernel.org/stable/c/4c03e6eb98443dc4d6d422a9780034a5b75376b4"},{"url":"https://git.kernel.org/stable/c/ff734dbd9e2432601a6dcd167cfb0bf8a36d1880"},{"url":"https://git.kernel.org/stable/c/ec427dc5286da1ed08f2d510e2147a7581b0cb02"},{"url":"https://git.kernel.org/stable/c/01d798e9feb30212952d4e992801ba6bd6a82351"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:26:19.497Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.2","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}