A flaw was found in the network scheduler in the Linux kernel. The problem happens because when offloading is enabled, the cbs instance is not added to the list. Also, the code didn't handle correctly the case when offload is disabled without removing the qdisc. This could lead to a NULL pointer dereference issue. Upstream commit: https://github.com/torvalds/linux/commit/3e8b9bfa110896f95d602d8c98d5f9d67e41d78c References: https://www.openwall.com/lists/oss-security/2024/01/30/3 https://nvd.nist.gov/vuln/detail/CVE-2021-33630
This CVE was fixed upstream in kernel version 5.4. The kernel packages as shipped in Red Hat Enterprise Linux 8 were previously updated to a version that contains the fix via the following errata: kernel in Red Hat Enterprise Linux 8 https://access.redhat.com/errata/RHSA-2020:1769 kernel-rt in Red Hat Enterprise Linux 8 https://access.redhat.com/errata/RHSA-2020:1567