CVE-2026-98631

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

xsk: Use a 32-bit compare in xsk_map_gen_lookup

xsk_map_gen_lookup() loads a u32 key and compares it with max_entries

using BPF_JMP_IMM. BPF immediates are sign-extended to 64 bits, so a

max_entries value of 0x80000000 or higher becomes a threshold larger

than every zero-extended 32-bit key. An out-of-range index then skips

the bounds check and the generated lookup reads past xsk_map[].

Compare with BPF_JMP32_IMM so the check stays in 32-bit unsigned range.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References