4xm: prevent overflow during block alignment calculation

[ffmpeg] / libavformat / fifo.c

diff --git a/libavformat/fifo.c b/libavformat/fifo.c
index 15435fe3080f50465aff5c76117aed1f4139cc4a..8f525e56cbaf65a46bd995213978816dd447d246 100644 (file)
--- 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)