{"id":"CVE-2026-52936","title":"crypto: jitterentropy - replace long-held spinlock with mutex","summary":"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 t…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < 21de77d06f6b540e870e64ef5ff56be4eb8ba08f","Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < 18216b8ab6904753eaf31baf453cb02ecd202ba4","Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < 4c03e6eb98443dc4d6d422a9780034a5b75376b4","Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < ff734dbd9e2432601a6dcd167cfb0bf8a36d1880","Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < ec427dc5286da1ed08f2d510e2147a7581b0cb02","Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < 01d798e9feb30212952d4e992801ba6bd6a82351","Linux 4.2"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T16:14:26.080799Z"},"published":"2026-06-24","updated":"2026-11-06","sourceUpdated":"2026-11-06T16:23:50.257Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-52936","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"}],"tags":["cve.org"],"epss":0.00114,"epssPercentile":0.01505,"ingestedAt":"2026-11-05T15:02:32.339Z","slug":"CVE-2026-52936","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < 21de77d06f6b540e870e64ef5ff56be4eb8ba08f`\n- `Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < 18216b8ab6904753eaf31baf453cb02ecd202ba4`\n- `Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < 4c03e6eb98443dc4d6d422a9780034a5b75376b4`\n- `Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < ff734dbd9e2432601a6dcd167cfb0bf8a36d1880`\n- `Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < ec427dc5286da1ed08f2d510e2147a7581b0cb02`\n- `Linux >= bb5530e4082446aac3a3d69780cd4dbfa4520013 < 01d798e9feb30212952d4e992801ba6bd6a82351`\n- `Linux 4.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}