avformat/mvdec: Check size in read_table() for validity

This check is redundant with the previous commit but it provides
better error messages and feedback while the previous commit
ensures that var_read_string() doesnt return uninitialized arrays
if it itself is feeded with an invalid size possibly through a
different future codepath.

Fixes: asan_heap-oob_49b1e5_12_011.movie
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2014-10-28 16:59:50 +01:00
parent 86e5749285
commit f1c21a200b

View File

@ -223,7 +223,7 @@ static int parse_video_var(AVFormatContext *avctx, AVStream *st,
return 0;
}
static void read_table(AVFormatContext *avctx, AVStream *st,
static int read_table(AVFormatContext *avctx, AVStream *st,
int (*parse)(AVFormatContext *avctx, AVStream *st,
const char *name, int size))
{
@ -238,11 +238,16 @@ static void read_table(AVFormatContext *avctx, AVStream *st,
avio_read(pb, name, 16);
name[sizeof(name) - 1] = 0;
size = avio_rb32(pb);
if (size < 0) {
av_log(avctx, AV_LOG_ERROR, "entry size %d is invalid\n", size);
return AVERROR_INVALIDDATA;
}
if (parse(avctx, st, name, size) < 0) {
avpriv_request_sample(avctx, "Variable %s", name);
avio_skip(pb, size);
}
}
return 0;
}
static void read_index(AVIOContext *pb, AVStream *st)
@ -268,6 +273,7 @@ static int mv_read_header(AVFormatContext *avctx)
AVIOContext *pb = avctx->pb;
AVStream *ast = NULL, *vst = NULL; //initialization to suppress warning
int version, i;
int ret;
avio_skip(pb, 4);
@ -340,7 +346,8 @@ static int mv_read_header(AVFormatContext *avctx)
} else if (!version && avio_rb16(pb) == 3) {
avio_skip(pb, 4);
read_table(avctx, NULL, parse_global_var);
if ((ret = read_table(avctx, NULL, parse_global_var)) < 0)
return ret;
if (mv->nb_audio_tracks > 1) {
avpriv_request_sample(avctx, "Multiple audio streams support");
@ -350,7 +357,8 @@ static int mv_read_header(AVFormatContext *avctx)
if (!ast)
return AVERROR(ENOMEM);
ast->codec->codec_type = AVMEDIA_TYPE_AUDIO;
read_table(avctx, ast, parse_audio_var);
if ((read_table(avctx, ast, parse_audio_var)) < 0)
return ret;
if (mv->acompression == 100 &&
mv->aformat == AUDIO_FORMAT_SIGNED &&
ast->codec->bits_per_coded_sample == 16) {
@ -376,7 +384,8 @@ static int mv_read_header(AVFormatContext *avctx)
if (!vst)
return AVERROR(ENOMEM);
vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
read_table(avctx, vst, parse_video_var);
if ((ret = read_table(avctx, vst, parse_video_var))<0)
return ret;
}
if (mv->nb_audio_tracks)