X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Flibvorbisdec.c;h=3c53b8fdaf243f16de6c13dddaad05c0925dd58c;hb=6268034b5d03580f86e9ff5a1879ebd56f35db40;hp=ecf690a5530128eef311ff8870b94ab689c40bcc;hpb=14fe81b3a88dfe4dbac12e8715f9a3f05b5ef1bf;p=ffmpeg

diff --git a/libavcodec/libvorbisdec.c b/libavcodec/libvorbisdec.c
index ecf690a5530..3c53b8fdaf2 100644
--- a/libavcodec/libvorbisdec.c
+++ b/libavcodec/libvorbisdec.c
@@ -49,29 +49,40 @@ static int oggvorbis_decode_init(AVCodecContext *avccontext) {
     vorbis_comment_init(&context->vc) ;
 
     if(p[0] == 0 && p[1] == 30) {
+        int sizesum = 0;
         for(i = 0; i < 3; i++){
             hsizes[i] = bytestream_get_be16((const uint8_t **)&p);
+            sizesum += 2 + hsizes[i];
+            if (sizesum > avccontext->extradata_size) {
+                av_log(avccontext, AV_LOG_ERROR, "vorbis extradata too small\n");
+                ret = AVERROR_INVALIDDATA;
+                goto error;
+            }
+
             headers[i] = p;
             p += hsizes[i];
         }
     } else if(*p == 2) {
         unsigned int offset = 1;
+        unsigned int sizesum = 1;
         p++;
         for(i=0; i<2; i++) {
             hsizes[i] = 0;
-            while((*p == 0xFF) && (offset < avccontext->extradata_size)) {
+            while((*p == 0xFF) && (sizesum < avccontext->extradata_size)) {
                 hsizes[i] += 0xFF;
                 offset++;
+                sizesum += 1 + 0xFF;
                 p++;
             }
-            if(offset >= avccontext->extradata_size - 1) {
+            hsizes[i] += *p;
+            offset++;
+            sizesum += 1 + *p;
+            if(sizesum > avccontext->extradata_size) {
                 av_log(avccontext, AV_LOG_ERROR,
                        "vorbis header sizes damaged\n");
                 ret = AVERROR_INVALIDDATA;
                 goto error;
             }
-            hsizes[i] += *p;
-            offset++;
             p++;
         }
         hsizes[2] = avccontext->extradata_size - hsizes[0]-hsizes[1]-offset;