[FFmpeg-devel] [PATCH 2/2] lavf/fifo: fix undefined behaviour in deinit when destroying mutex

[Jan Sebechlebsky]

On 11/12/2016 02:23 AM, Marton Balint wrote:

> Signed-off-by: Marton Balint <cus at passwd.hu>
> ---
>   libavformat/fifo.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/libavformat/fifo.c b/libavformat/fifo.c
> index 15435fe..8f525e5 100644
> --- a/libavformat/fifo.c
> +++ b/libavformat/fifo.c
> @@ -73,6 +73,7 @@ typedef struct FifoContext {
>       int restart_with_keyframe;
>   
>       pthread_mutex_t overflow_flag_lock;
> +    int overflow_flag_lock_initialized;
>       /* Value > 0 signals queue overflow */
>       volatile uint8_t overflow_flag;
>   
> @@ -515,6 +516,7 @@ static int fifo_init(AVFormatContext *avf)
>       ret = pthread_mutex_init(&fifo->overflow_flag_lock, NULL);
>       if (ret < 0)
>           return AVERROR(ret);
> +    fifo->overflow_flag_lock_initialized = 1;
>   
>       return 0;
>   }
> @@ -601,7 +603,8 @@ static void fifo_deinit(AVFormatContext *avf)
>       av_dict_free(&fifo->format_options);
>       avformat_free_context(fifo->avf);
>       av_thread_message_queue_free(&fifo->queue);
> -    pthread_mutex_destroy(&fifo->overflow_flag_lock);
> +    if (fifo->overflow_flag_lock_initialized)
> +        pthread_mutex_destroy(&fifo->overflow_flag_lock);
>   }
>   
>   #define OFFSET(x) offsetof(FifoContext, x)
LGTM, thanks! :)

Reviewed-by: jsebechlebsky