CVE-2025-37915

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net_sched: drr: Fix double list add in class with netem as child qdisc<br /> <br /> As described in Gerrard&amp;#39;s report [1], there are use cases where a netem<br /> child qdisc will make the parent qdisc&amp;#39;s enqueue callback reentrant.<br /> In the case of drr, there won&amp;#39;t be a UAF, but the code will add the same<br /> classifier to the list twice, which will cause memory corruption.<br /> <br /> In addition to checking for qlen being zero, this patch checks whether the<br /> class was already added to the active_list (cl_is_active) before adding<br /> to the list to cover for the reentrant case.<br /> <br /> [1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/