On Sat, Aug 27, 2022 at 1:16 AM Andrii Nakryiko <andrii@xxxxxxxxxx> wrote:
>
> Fix SIGSEGV caused by libbpf trying to find attach type in vmlinux BTF
> for freplace programs. It's wrong to search in vmlinux BTF and libbpf
> doesn't even mark vmlinux BTF as required for freplace programs. So
> trying to search anything in obj->vmlinux_btf might cause NULL
> dereference if nothing else in BPF object requires vmlinux BTF.
>
> Instead, error out if freplace (EXT) program doesn't specify
> attach_prog_fd during at the load time.
>
> Fixes: 91abb4a6d79d ("libbpf: Support attachment of BPF tracing programs to kernel modules")
> Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Acked-by: KP Singh <kpsingh@xxxxxxxxxx>
