[FFmpeg-devel] [PATCH] avformat/dashdec: check NULL pointer of av_strtok

[Leo Izen]

On 12/26/24 6:37 PM, Steven Liu wrote:
> fix CID: 1637073
> there maybe have NULL pointer return by av_strtok, and should be checked before
> strtoll it.
> 
> Signed-off-by: Steven Liu <lq at chinaffmpeg.org>
> ---
>   libavformat/dashdec.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/libavformat/dashdec.c b/libavformat/dashdec.c
> index 8107280444..043cd52232 100644
> --- a/libavformat/dashdec.c
> +++ b/libavformat/dashdec.c
> @@ -589,6 +589,8 @@ static struct fragment *get_fragment(char *range)
>       if (range) {
>           char *str_end_offset;
>           char *str_offset = av_strtok(range, "-", &str_end_offset);
> +        if (!str_offset)
> +            return NULL;
>           seg->url_offset = strtoll(str_offset, NULL, 10);
>           seg->size = strtoll(str_end_offset, NULL, 10) - seg->url_offset + 1;
>       }

If the range is invalid, do we want to return NULL? What if the range is 
a single integer, do we want to return that integer? What about 
returning an empty segment struct (as though the range == NULL)? It 
looks fine for preventing a NULL dereference, I just want to check to 
make sure this behavior is desired if the "-" token is not found.

- Leo Izen (Traneptora)