On Sat, May 10, 2025 at 11:16 AM Anton Protopopov
<a.s.protopopov@xxxxxxxxx> wrote:
>
> Return value of the validate_nla() function can be propagated all the
> way up to users of libbpf API. In case of error this libbpf version
> of validate_nla returns -1 which will be seen as -EPERM from user's
> point of view. Instead, return a more reasonable -EINVAL.
>
> Fixes: bbf48c18ee0c ("libbpf: add error reporting in XDP")
> Suggested-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> Signed-off-by: Anton Protopopov <a.s.protopopov@xxxxxxxxx>
> ---
> tools/lib/bpf/nlattr.c | 12 +++++-------
> 1 file changed, 5 insertions(+), 7 deletions(-)
>
Thanks for the clean up fix! Applied to bpf-next.
> diff --git a/tools/lib/bpf/nlattr.c b/tools/lib/bpf/nlattr.c
> index 975e265eab3b..0ba527d33ce4 100644
> --- a/tools/lib/bpf/nlattr.c
> +++ b/tools/lib/bpf/nlattr.c
> @@ -63,16 +63,16 @@ static int validate_nla(struct nlattr *nla, int maxtype,
> minlen = nla_attr_minlen[pt->type];
>
> if (libbpf_nla_len(nla) < minlen)
> - return -1;
> + return -EINVAL;
>
> if (pt->maxlen && libbpf_nla_len(nla) > pt->maxlen)
> - return -1;
> + return -EINVAL;
>
> if (pt->type == LIBBPF_NLA_STRING) {
> char *data = libbpf_nla_data(nla);
>
> if (data[libbpf_nla_len(nla) - 1] != '\0')
> - return -1;
> + return -EINVAL;
> }
>
> return 0;
> @@ -118,7 +118,7 @@ int libbpf_nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head,
> if (policy) {
> err = validate_nla(nla, maxtype, policy);
> if (err < 0)
> - goto errout;
> + return err;
> }
>
> if (tb[type])
> @@ -128,9 +128,7 @@ int libbpf_nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head,
> tb[type] = nla;
> }
>
> - err = 0;
> -errout:
> - return err;
> + return 0;
> }
>
> /**
> --
> 2.34.1
>
