Bugzilla – Bug 1226797
VUL-0: CVE-2024-36244: kernel: net/sched: taprio: extend minimum interval restriction to entire cycle too
Last modified: 2024-07-04 10:20:23 UTC
In the Linux kernel, the following vulnerability has been resolved: net/sched: taprio: extend minimum interval restriction to entire cycle too It is possible for syzbot to side-step the restriction imposed by the blamed commit in the Fixes: tag, because the taprio UAPI permits a cycle-time different from (and potentially shorter than) the sum of entry intervals. We need one more restriction, which is that the cycle time itself must be larger than N * ETH_ZLEN bit times, where N is the number of schedule entries. This restriction needs to apply regardless of whether the cycle time came from the user or was the implicit, auto-calculated value, so we move the existing "cycle == 0" check outside the "if "(!new->cycle_time)" branch. This way covers both conditions and scenarios. Add a selftest which illustrates the issue triggered by syzbot. References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-36244 https://www.cve.org/CVERecord?id=CVE-2024-36244 https://git.kernel.org/stable/c/91f249b01fe490fce11fbb4307952ca8cce78724 https://git.kernel.org/stable/c/b939d1e04a90248b4cdf417b0969c270ceb992b2 https://git.kernel.org/stable/c/fb66df20a7201e60f2b13d7f95d031b31a8831d3 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-36244.mbox https://bugzilla.redhat.com/show_bug.cgi?id=2293654