ffmpeg | branch: master | Michael Niedermayer <mich...@niedermayer.cc> | Thu Sep 8 19:55:24 2016 +0200| [47ffcddaefeeb5c994af2ae2a09f34a91bc1ed28] | committer: Michael Niedermayer
avcodec/mlz: Check output chars before using it Fixes hypothetical integer overflow Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=47ffcddaefeeb5c994af2ae2a09f34a91bc1ed28 --- libavcodec/mlz.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/libavcodec/mlz.c b/libavcodec/mlz.c index 039635d..a2d1b89 100644 --- a/libavcodec/mlz.c +++ b/libavcodec/mlz.c @@ -153,12 +153,27 @@ int ff_mlz_decompression(MLZ* mlz, GetBitContext* gb, int size, unsigned char *b mlz->bump_code = mlz->current_dic_index_max - 1; } else { if (string_code >= mlz->next_code) { - output_chars += decode_string(mlz, &buff[output_chars], last_string_code, &char_code, size - output_chars); - output_chars += decode_string(mlz, &buff[output_chars], char_code, &char_code, size - output_chars); + int ret = decode_string(mlz, &buff[output_chars], last_string_code, &char_code, size - output_chars); + if (ret < 0 || ret > size - output_chars) { + av_log(mlz->context, AV_LOG_ERROR, "output chars overflow\n"); + return output_chars; + } + output_chars += ret; + ret = decode_string(mlz, &buff[output_chars], char_code, &char_code, size - output_chars); + if (ret < 0 || ret > size - output_chars) { + av_log(mlz->context, AV_LOG_ERROR, "output chars overflow\n"); + return output_chars; + } + output_chars += ret; set_new_entry_dict(dict, mlz->next_code, last_string_code, char_code); mlz->next_code++; } else { - output_chars += decode_string(mlz, &buff[output_chars], string_code, &char_code, size - output_chars); + int ret = decode_string(mlz, &buff[output_chars], string_code, &char_code, size - output_chars); + if (ret < 0 || ret > size - output_chars) { + av_log(mlz->context, AV_LOG_ERROR, "output chars overflow\n"); + return output_chars; + } + output_chars += ret; if (output_chars <= size && !mlz->freeze_flag) { if (last_string_code != -1) { set_new_entry_dict(dict, mlz->next_code, last_string_code, char_code); _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog