Re: [PATCH] libbpf: Initialize st_ops->tname with strdup()

[Andrii Nakryiko]

On Tue, Aug 20, 2024 at 11:48 PM Soma Nakata <soma.nakata01@xxxxxxxxx> wrote:
>
> `tname` is returned by `btf__name_by_offset()` as well as `var_name`,
> and these addresses point to strings in the btf. Since their locations
> may change while loading the bpf program, using `strdup()` ensures
> `tname` is safely stored.
>
> Signed-off-by: Soma Nakata <soma.nakata01@xxxxxxxxx>
> ---
>  tools/lib/bpf/libbpf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index a3be6f8fac09..ece1f1af2cd4 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -1423,7 +1423,7 @@ static int init_struct_ops_maps(struct bpf_object *obj, const char *sec_name,
>                 memcpy(st_ops->data,
>                        data->d_buf + vsi->offset,
>                        type->size);
> -               st_ops->tname = tname;
> +               st_ops->tname = strdup(tname);
>                 st_ops->type = type;
>                 st_ops->type_id = type_id;
>

Thanks for the fix, but this has been fixed already ([0]). Please make
sure that you always reproduce the issue on bpf-next/master and send a
fix against that branch.

  [0] https://lore.kernel.org/bpf/20240724171459.281234-1-void@xxxxxxxxxxxxx/

pw-bot: cr

> --
> 2.46.0
>