CVE-2026-72068
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.
Executive briefing
The source record describes: 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. The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.
Evidence confidence: Low Evidence-derived, not an exploitability verdict
Severity & attack characteristics
CVSS vector:
No CVSS vector is currently available in the source record.
Technical explanation & impact
The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.
Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.
Affected products and versions
NVD has not supplied machine-readable vulnerable CPE product/version entries for this CVE. This is an information gap, not proof that no products are affected. Check the vendor advisory references below.
Remediation & validation
- Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
- Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
- Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
- Validate the remediation with a version check and vulnerability rescan, then retain change evidence.
No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.
Vendor advisories, patches & exploit references
- https://git.kernel.org/stable/c/1fafc4d9b411645eb34de43362b966dc8fb3e263 REFERENCE 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/26aff38fefb1d6cd87e22525f41cc8f1aa61b24f REFERENCE 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/384628d6cdde0fcd76868606fad3ad8293100afb REFERENCE 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/571e1f10b5996ba3e4dc63ea77de4aa309c384ce REFERENCE 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/cff8281bacd2866767e6194c3079d33b6c5a74f4 REFERENCE 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/ea6a188ee805e841a0e242f14d15953e0dfa74bb REFERENCE 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/edf6babb9edd2d3e19229ade339081f439d4f478 REFERENCE 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/feb5c87c8514444ba891b75a5a3eae57c64edaf8 REFERENCE 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Information gaps & confidence notes
These gaps indicate missing source data. CVE Watch does not fill them with guessed product, exploit or patch details.
- NVD does not currently provide machine-readable vulnerable CPE product/version entries for this record.
- No vendor advisory or patch reference was identified in the supplied CVE references.
- No CVSS vector is currently available in the source record.
- No CWE classification is currently available.
Last enrichment: 2026-11-07T16:38:42+00:00 · Source last modified: 2026-11-06T17:19:36.033