Re: [PATCH bpf-next v2] libbpf: Fix strncat bounds error in libbpf_prog_type_by_name

From: Alexei Starovoitov
Date: Wed Oct 23 2019 - 13:19:13 EST


On Wed, Oct 23, 2019 at 8:40 AM KP Singh <kpsingh@xxxxxxxxxxxx> wrote:
>
> From: KP Singh <kpsingh@xxxxxxxxxx>
>
> On compiling samples with this change, one gets an error:
>
> error: âstrncatâ specified bound 118 equals destination size
> [-Werror=stringop-truncation]
>
> strncat(dst, name + section_names[i].len,
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> sizeof(raw_tp_btf_name) - (dst - raw_tp_btf_name));
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> strncat requires the destination to have enough space for the
> terminating null byte.
>
> Fixes: f75a697e09137 ("libbpf: Auto-detect btf_id of BTF-based raw_tracepoint")
> Signed-off-by: KP Singh <kpsingh@xxxxxxxxxx>

Applied. Thanks