CVE-2026-52936

crypto: jitterentropy - replace long-held spinlock with mutex

MEDIUM
5.5
CVSS Score
Published: June 24, 2026 at 07:14 AM UTC
Updated: October 30, 2026 at 01:19 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

4.2 ≤ v < 6.6.1416.13 ≤ v < 6.18.336.19 ≤ v < 7.0.106.7 ≤ v < 6.12.914.2bb5530e4082446aac3a3d69780cd4dbfa4520013
Vendor states this is fixed in 01d798e9feb30212952d4e992801ba6bd6a82351 (fixed)
Vendor states this is fixed in 18216b8ab6904753eaf31baf453cb02ecd202ba4 (fixed)
Vendor states this is fixed in 4c03e6eb98443dc4d6d422a9780034a5b75376b4 (fixed)
Vendor states this is fixed in ec427dc5286da1ed08f2d510e2147a7581b0cb02 (fixed)
Vendor states this is fixed in ff734dbd9e2432601a6dcd167cfb0bf8a36d1880 (fixed)
Vendor states this is fixed in 4.2 (unaffected)
Vendor states this is fixed in 6.12.91 (unaffected)
Vendor states this is fixed in 6.18.33 (unaffected)
Vendor states this is fixed in 6.6.141 (unaffected)
Vendor states this is fixed in 7.0.10 (unaffected)
Vendor states this is fixed in 7.1 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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