avcodec/htmlsubtitles: Check for string truncation and return error
authorMichael Niedermayer <michael@niedermayer.cc>
Fri, 5 May 2017 23:42:53 +0000 (01:42 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Sat, 20 May 2017 01:41:33 +0000 (03:41 +0200)
Fixes out of array access
Fixes: 1354/clusterfuzz-testcase-minimized-5520132195483648

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit f4ae3cce64bd46b1d539bdeac39753f83015f114)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/srtdec.c

index a9e7a53..0fd651c 100644 (file)
@@ -49,11 +49,12 @@ typedef struct SrtStack {
 
 static void rstrip_spaces_buf(AVBPrint *buf)
 {
-    while (buf->len > 0 && buf->str[buf->len - 1] == ' ')
-        buf->str[--buf->len] = 0;
+    if (av_bprint_is_complete(buf))
+        while (buf->len > 0 && buf->str[buf->len - 1] == ' ')
+            buf->str[--buf->len] = 0;
 }
 
-static void srt_to_ass(AVCodecContext *avctx, AVBPrint *dst,
+static int srt_to_ass(AVCodecContext *avctx, AVBPrint *dst,
                        const char *in, int x1, int y1, int x2, int y2)
 {
     char *param, buffer[128], tmp[128];
@@ -191,10 +192,15 @@ static void srt_to_ass(AVCodecContext *avctx, AVBPrint *dst,
             line_start = 0;
     }
 
+    if (!av_bprint_is_complete(dst))
+        return AVERROR(ENOMEM);
+
     while (dst->len >= 2 && !strncmp(&dst->str[dst->len - 2], "\\N", 2))
         dst->len -= 2;
     dst->str[dst->len] = 0;
     rstrip_spaces_buf(dst);
+
+    return 0;
 }
 
 static int srt_decode_frame(AVCodecContext *avctx,