Affected: Linux, Siemens RUGGEDCOM RST2428P, Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family, Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family, Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

In the Linux kernel, the following vulnerability has been resolved:

net/sched: taprio: always validate TCA_TAPRIO_ATTR_PRIOMAP

If one TCA_TAPRIO_ATTR_PRIOMAP attribute has been provided, taprio_parse_mqprio_opt() must validate it, or userspace can inject arbitrary data to the kernel, the second time taprio_change() is called.

First call (with valid attributes) sets dev->num_tc to a non zero value.

Second call (with arbitrary mqprio attributes) returns early from taprio_parse_mqprio_opt() and bad things can happen.