Oracle Linux: CVE-2020-8835: ELSA-2020-5663: Unbreakable Enterprise kernel security update (IMPORTANT)

In the Linux kernel 5.5.0 and newer, the bpf verifier (kernel/bpf/verifier.c) did not properly restrict the register bounds for 32-bit operations, leading to out-of-bounds reads and writes in kernel memory. The vulnerability also affects the Linux 5.4 stable series, starting with v5.4.7, as the introducing commit was backported to that branch. This vulnerability was fixed in 5.6.1, 5.5.14, and 5.4.29. (issue is aka ZDI-CAN-10780)
An out-of-bounds access flaw was found in the Linux kernel’s implementation of the eBPF code verifier, where an incorrect register bounds calculation while checking 32-bit instructions in an eBPF program occurs. This flaw allows an unprivileged user or process to execute eBPF programs to crash the kernel, resulting in a denial of service or potentially gaining root privileges on the system.