avcodec/htmlsubtitles: Fix reading one byte beyond the array
authorMichael Niedermayer <michael@niedermayer.cc>
Fri, 11 Nov 2016 01:25:42 +0000 (02:25 +0100)
committerMichael Niedermayer <michael@niedermayer.cc>
Sat, 12 Nov 2016 02:23:03 +0000 (03:23 +0100)
Fixes: fuzz-2-ffmpeg_SUBTITLE_AV_CODEC_ID_SUBRIP_fuzzer

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/htmlsubtitles.c

index a2cd40f..8b57feb 100644 (file)
@@ -146,7 +146,7 @@ void ff_htmlmarkup_to_ass(void *log_ctx, AVBPrint *dst, const char *in)
                                 if (stack[sptr].param[i][0])
                                     av_bprintf(dst, "%s", stack[sptr].param[i]);
                         }
-                    } else if (!tagname[1] && strspn(tagname, "bisu") == 1) {
+                    } else if (tagname[0] && !tagname[1] && strspn(tagname, "bisu") == 1) {
                         av_bprintf(dst, "{\\%c%d}", tagname[0], !tag_close);
                     } else {
                         unknown = 1;