CVE-2025-38591 bpf: Reject narrower access to pointer ctx fields

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject narrower access to pointer ctx fields The following BPF program, simplified from a syzkaller repro, causes a kernel warning: r0 = u8 r1 + 169; exit; With pointer field sk being at offset 168 in skbuff. This access is...