CVE-2026-98151 bpf: Fix REG INVARIANTS VIOLATION on speculative pointer arithmetic

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix REG INVARIANTS VIOLATION on speculative pointer arithmetic Take the following unprivileged program as an example: r0 = bpfmaplookupelem... / PTRTOMAPVALUE, offset 0 / ... 14: r0 += r1 / r1 is a bounded scalar / 15: r9 = ...