CVE Catalog

CVE-2026-72068

Low risk· EPSS 13%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.22%

13th percentile - higher than 13% of all known CVEs

Summary

In the Linux kernel, the posix-cpu-timers mechanism has a multiplication bug in update_rlimit_cpu(). On 32-bit kernels, multiplying the CPU limit by NSEC_PER_SEC is done in 32-bit type, causing truncation for limits >= 5 seconds and incorrect programming of the process CPU timer.

Risk Assessment

The bug causes premature firing of the process CPU timer, potentially leading to unexpected SIGXCPU/SIGKILL signals for processes with CPU limits, disrupting their operation.

Recommendation

Apply the Linux kernel patch that adds a u64 cast in the multiplication in update_rlimit_cpu() to avoid truncation.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: posix-cpu-timers: Use u64 multiplication in update_rlimit_cpu() update_rlimit_cpu() converts the RLIMIT_CPU value to nanoseconds with u64 nsecs = rlim_new * NSEC_PER_SEC; On 32-bit kernels both rlim_new (unsigned long) and NSEC_PER_SEC (1000000000L) are 32-bit, so the multiplication is performed in unsigned long and truncated for rlim_new > 4 seconds before being widened to u64. The same file already casts to u64 for the matching computation in check_process_timers(): u64 softns = (u64)soft * NSEC_PER_SEC; As a result, the truncated value is installed into the CPUCLOCK_PROF expiry cache (nextevt), causing the process CPU timer to be programmed to fire prematurely for any RLIMIT_CPU soft limit >= 5 seconds. The actual SIGXCPU/SIGKILL decision in check_process_timers() already casts to u64 and is therefore correct, so limit enforcement is not broken; only the expiry-cache programming is wrong. Apply the same cast here so both paths convert rlim_cur identically. 64-bit kernels are unaffected.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS