kernel: bpf: Reject pkt arguments in mutating subprogs (CVE-2026-98589)

Overview

A flaw was found in the Linux kernel's BPF (Berkeley Packet Filter) verifier. When packet pointers are passed into subprograms that mutate packet data, the verifier incorrectly assumes the underlying memory remains valid across calls, failing to account for operations that invalidate or relocate packet buffers. A local user with permissions to load BPF programs can exploit this flaw to cause memory corruption, potentially leading to a Denial of Service (DoS) or privilege escalation.

Vendor advisories

• Red Hat VEX · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, … · updated 2026-10-20 · vex

kernel: bpf: Reject pkt arguments in mutating subprogs — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-20.

Affected:

• Red Hat Enterprise Linux 10
• Red Hat Enterprise Linux 7
• Red Hat Enterprise Linux 8
• Red Hat Enterprise Linux 9
• Red Hat OpenShift Container Platform 4

No fix planned:

• Red Hat Enterprise Linux 10
• Red Hat Enterprise Linux 7
• Red Hat Enterprise Linux 8
• Red Hat Enterprise Linux 9
• Red Hat OpenShift Container Platform 4

Not affected:

• Red Hat Enterprise Linux 6

Remediation

Fix deferred