Inefficient Algorithmic Complexity in Linux kernel - CVE-2026-98628

Vulnerability details

The vulnerability allows a local privileged user to cause a denial of service through prolonged CPU consumption and delayed termination of a BPF loader task.

The vulnerability exists due to inefficient algorithmic complexity and missing signal checks and rescheduling points in the Linux kernel BPF post-verification instruction rewrite passes when processing specially crafted BPF programs. A local privileged user can submit a program containing 131072 unconditional jumps by zero followed by a valid return to trigger quadratic instruction removal in bpf_opt_remove_nops(), consuming CPU resources and preventing a pending SIGKILL from terminating the loader until rewriting finishes.

Affected software

How to mitigate CVE-2026-98628

External References

• https://git.kernel.org/stable/c/261b61d3735b042ae25634f795c4540be0fc140c
• https://git.kernel.org/stable/c/56dc616d7a1f7d134d3e101c455e62b0a24d0cfd

Related Security Bulletins

• Inefficient Algorithmic Complexity in Linux kernel bpf
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more