CVE-2021-47317

A flaw was found in the Linux kernel's PowerPC Berkeley Packet Filter (BPF) Just-In-Time (JIT) compiler. When evaluating BPF programs, the verification check fails to examine the correct instruction field for certain atomic operations. A local user with permissions to load BPF programs could exploit this flaw by loading crafted programs, causing improper code compilation that results in a kernel hang and a Denial of Service (DoS).

This vulnerability is rated as Low severity because successful exploitation requires elevated local administrative privileges (CAP_BPF or CAP_SYS_ADMIN) on 64-bit PowerPC architectures to trigger a denial of service. By default, Red Hat Enterprise Linux disables unprivileged eBPF access, preventing standard users from loading BPF programs into the kernel. Consequently, the flaw cannot be triggered across other hardware platforms or by non-privileged accounts, limiting the blast radius to environments where authorized administrators execute non-standard atomic BPF instructions.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.