CRYP-7902 excessively slow on Linux 6.x kernels with haveged running

CRYP-7902 consistently takes over 6 minutes to complete (368.423856 seconds), triggering a long-execution warning, despite the system having a healthy entropy setup.

Environment

• Lynis version: 3.1.6
• OS: Debian 13
• Kernel: 6.12.74+deb13+1-amd64
• Entropy daemon: haveged

Describe the issue

CRYP-7902 consistently takes over 6 minutes to complete (368.423856 seconds), triggering a long-execution warning, despite the system having a healthy entropy setup.

Log output

  #  lynis audit system --quiet
  [WARNING]: Test HTTP-6708 had a long execution: 11.248315 seconds
  [WARNING]: Test CRYP-7902 had a long execution: 368.423856 seconds

Relevant system state

$ cat /proc/sys/kernel/random/entropy_avail
256
$ ps aux | grep haveged
root  683  0.0  0.0  8520  680 ?  Ss  Mar30  0:51 /usr/sbin/haveged --Foreground --verbose=1

Analysis

On Linux kernel 5.6+, /dev/random no longer blocks regardless of entropy pool state, and the kernel intentionally caps entropy_avail at 256 bits (the CRNG is considered fully seeded at this level). The test appears to be running a legacy entropy estimation loop that predates this kernel behavior change, causing it to spin for several minutes before completing.

Expected behavior

CRYP-7902 should complete in a reasonable time on kernels 5.6+ where /dev/random is non-blocking by design.

Suggested fix

Consider adding a kernel version check in CRYP-7902 — on kernels >= 5.6, the test logic or timeout threshold may need to be adjusted to account for the new CRNG behavior.