avcodec/h264: Check mode before considering mixed mode intra prediction

Fixes out of array read
Fixes: asan_heap-oob_e476fc_2_asan_heap-oob_1333ec6_61_CAMACI3_Sony_C.jsv

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2014-10-04 14:51:46 +02:00
parent 138902dfb6
commit 9734a7a1de

View File

@ -215,18 +215,18 @@ int ff_h264_check_intra_pred_mode(H264Context *h, int mode, int is_chroma)
if ((h->left_samples_available & 0x8080) != 0x8080) {
mode = left[mode];
if (is_chroma && (h->left_samples_available & 0x8080)) {
// mad cow disease mode, aka MBAFF + constrained_intra_pred
mode = ALZHEIMER_DC_L0T_PRED8x8 +
(!(h->left_samples_available & 0x8000)) +
2 * (mode == DC_128_PRED8x8);
}
if (mode < 0) {
av_log(h->avctx, AV_LOG_ERROR,
"left block unavailable for requested intra mode at %d %d\n",
h->mb_x, h->mb_y);
return AVERROR_INVALIDDATA;
}
if (is_chroma && (h->left_samples_available & 0x8080)) {
// mad cow disease mode, aka MBAFF + constrained_intra_pred
mode = ALZHEIMER_DC_L0T_PRED8x8 +
(!(h->left_samples_available & 0x8000)) +
2 * (mode == DC_128_PRED8x8);
}
}
return mode;