CVE-2026-98627

/// Technical description

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

bpf: Preserve packet pointer class displacement in regsafe()

regsafe() maps packet pointer IDs between states and checks that each

current register range is a subset of the corresponding explored

register range. It does not, however, preserve the displacement between

registers that share a packet pointer ID.

This is unsound because packet range is shared by ID. A bounds check on

one class member updates every member, and a later access can consume the

range through another member. Commit 022ac0750883 ("bpf: use reg->var_off

instead of reg->off for pointers") folded the fixed pointer offset into

r64 and removed the old off equality check, so two individually narrower

registers can prune even when their displacement has changed. The

explored path can then license an out-of-bounds packet access on the

pruned path.

Require matching range bases for packet pointers with an ID. Together

with the existing ID mapping, this

/// 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