CVE-2026-52936

Summary

In the Linux kernel, the following vulnerability has been resolved:

crypto: jitterentropy - replace long-held spinlock with mutex

jent_kcapi_random() serializes the shared jitterentropy state, but it currently holds a spinlock across the jent_read_entropy() call. That path performs expensive jitter collection and SHA3 conditioning, so parallel readers can trigger stalls as contending waiters spin for the same lock.

To prevent non-preemptible lock hold, replace rng->jent_lock with a mutex so contended readers sleep instead of spinning on a shared lock held across expensive entropy generation.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxbb5530e4082446aac3a3d69780cd4dbfa4520013 < 18216b8ab6904753eaf31baf453cb02ecd202ba4affected
LinuxLinuxbb5530e4082446aac3a3d69780cd4dbfa4520013 < 4c03e6eb98443dc4d6d422a9780034a5b75376b4affected
LinuxLinuxbb5530e4082446aac3a3d69780cd4dbfa4520013 < ff734dbd9e2432601a6dcd167cfb0bf8a36d1880affected
LinuxLinuxbb5530e4082446aac3a3d69780cd4dbfa4520013 < ec427dc5286da1ed08f2d510e2147a7581b0cb02affected
LinuxLinuxbb5530e4082446aac3a3d69780cd4dbfa4520013 < 01d798e9feb30212952d4e992801ba6bd6a82351affected
LinuxLinux4.2affected
LinuxLinux0 < 4.2unaffected
LinuxLinux6.6.141 <= 6.6.*unaffected
LinuxLinux6.12.91 <= 6.12.*unaffected
LinuxLinux6.18.33 <= 6.18.*unaffected
LinuxLinux7.0.10 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

References