Re: [PATCH v2] libselinux: Add missing errno setup

[Ondrej Mosnacek <omosnace@redhat.com>]

On Mon, May 4, 2020 at 10:45 AM Richard Filo <rfilo@redhat.com> wrote:
> Errno is not set to ENOENT when lookup_all() doesn't find any match.
>
> fixes: https://src.fedoraproject.org/tests/selinux/issue/51
>
> Signed-off-by: Richard Filo <rfilo@redhat.com>
> ---
>  libselinux/src/label_file.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/libselinux/src/label_file.c b/libselinux/src/label_file.c
> index 300625c2..113bb9b7 100644
> --- a/libselinux/src/label_file.c
> +++ b/libselinux/src/label_file.c
> @@ -948,6 +948,8 @@ static const struct spec **lookup_all(struct selabel_handle *rec,
>                         goto finish;
>                 }
>         }
> +       if (result && !result[0])
> +               errno = ENOENT;

Sorry for not spotting this earlier, but there is no need to check if
result != NULL, because it will always be non-NULL at this point. So
you should only do the second part of the check (!result[0]). The
check under the "finish" label needs to check both, because you can
get there also via the allocation-failed path, where "result" would be
NULL.

>
>  finish:
>         free(clean_key);
> --
> 2.25.2
>

-- 
Ondrej Mosnacek <omosnace at redhat dot com>
Software Engineer, Security Technologies
Red Hat, Inc.