CVE-2023-52942

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> cgroup/cpuset: Fix wrong check in update_parent_subparts_cpumask()<br /> <br /> It was found that the check to see if a partition could use up all<br /> the cpus from the parent cpuset in update_parent_subparts_cpumask()<br /> was incorrect. As a result, it is possible to leave parent with no<br /> effective cpu left even if there are tasks in the parent cpuset. This<br /> can lead to system panic as reported in [1].<br /> <br /> Fix this probem by updating the check to fail the enabling the partition<br /> if parent&amp;#39;s effective_cpus is a subset of the child&amp;#39;s cpus_allowed.<br /> <br /> Also record the error code when an error happens in update_prstate()<br /> and add a test case where parent partition and child have the same cpu<br /> list and parent has task. Enabling partition in the child will fail in<br /> this case.<br /> <br /> [1] https://www.spinics.net/lists/cgroups/msg36254.html