indeo5dec: Make sure we have had a valid gop header.

This prevents decoding happening on a half initialized context.

Fixes CVE-2012-2779

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Anton Khirnov <anton@khirnov.net>
(cherry picked from commit 891918431db628db17885ed947ee387b29826a64)

Conflicts:

	libavcodec/ivi_common.c
	libavcodec/ivi_common.h
This commit is contained in:
Michael Niedermayer 2012-03-24 17:43:55 +01:00 committed by Reinhard Tartler
parent 801eff785a
commit 03ddc26066

View File

@ -76,6 +76,8 @@ typedef struct {
int is_scalable;
uint32_t lock_word;
IVIPicConfig pic_conf;
int gop_invalid;
} IVI5DecContext;
@ -335,8 +337,12 @@ static int decode_pic_hdr(IVI5DecContext *ctx, AVCodecContext *avctx)
ctx->frame_num = get_bits(&ctx->gb, 8);
if (ctx->frame_type == FRAMETYPE_INTRA) {
if (decode_gop_header(ctx, avctx))
return -1;
ctx->gop_invalid = 1;
if (decode_gop_header(ctx, avctx)) {
av_log(avctx, AV_LOG_ERROR, "Invalid GOP header, skipping frames.\n");
return AVERROR_INVALIDDATA;
}
ctx->gop_invalid = 0;
}
if (ctx->frame_type != FRAMETYPE_NULL) {
@ -759,6 +765,8 @@ static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
"Error while decoding picture header: %d\n", result);
return -1;
}
if (ctx->gop_invalid)
return AVERROR_INVALIDDATA;
if (ctx->gop_flags & IVI5_IS_PROTECTED) {
av_log(avctx, AV_LOG_ERROR, "Password-protected clip!\n");