Divide-by-Zero Vulnerability in Linux Kernel Networking Scheduler

CVE-2026-31423

What is CVE-2026-31423?

A divide-by-zero vulnerability exists in the Linux kernel's networking scheduler module, specifically in sch_hfsc, caused by improper handling of a scaled value derived from user inputs. When large values are processed, the calculation may lead to a situation where a division operation attempts to use zero as a divisor. This can result in system crashes, as evidenced by the runtime error messages produced. The fix involves extending variable types to ensure that critical calculations preserve value integrity, thus preventing potential system disruptions.

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