CVE-2026-53081 bpf: Enforce regsafe base id consistency for BPF_ADD_CONST scalars

In the Linux kernel, the following vulnerability has been resolved: bpf: Enforce regsafe base id consistency for BPFADDCONST scalars When regsafe compares two scalar registers that both carry BPFADDCONST, checkscalarids maps their full compound id aka base | BPFADDCONST flag as one idmap entry...