From 9734a7a1de3043f012ad0f1ef11027d9488067e6 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 4 Oct 2014 14:51:46 +0200 Subject: [PATCH] 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 --- libavcodec/h264.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/libavcodec/h264.c b/libavcodec/h264.c index 69fb047d5a..c4f4b052ff 100644 --- a/libavcodec/h264.c +++ b/libavcodec/h264.c @@ -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;