From eeece50aa2f420a96824246ee54bf836a857d823 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 14 May 2017 16:47:13 +0200 Subject: [PATCH] avcodec/mpeg4videodec: Clear sprite wraping on unsupported cases in VOP decode Fixes: Integer overflow Fixes: 1572/clusterfuzz-testcase-minimized-4578773729017856 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 467677769a2222ff8beab3c4d7826df9b7cbc81b) Signed-off-by: Michael Niedermayer --- libavcodec/mpeg4videodec.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c index c41f6aa8b6..fc1c8297b9 100644 --- a/libavcodec/mpeg4videodec.c +++ b/libavcodec/mpeg4videodec.c @@ -2438,16 +2438,20 @@ static int decode_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb) ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan); } - if (s->pict_type == AV_PICTURE_TYPE_S && - (ctx->vol_sprite_usage == STATIC_SPRITE || - ctx->vol_sprite_usage == GMC_SPRITE)) { - if (mpeg4_decode_sprite_trajectory(ctx, gb) < 0) - return AVERROR_INVALIDDATA; - if (ctx->sprite_brightness_change) - av_log(s->avctx, AV_LOG_ERROR, - "sprite_brightness_change not supported\n"); - if (ctx->vol_sprite_usage == STATIC_SPRITE) - av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n"); + if (s->pict_type == AV_PICTURE_TYPE_S) { + if((ctx->vol_sprite_usage == STATIC_SPRITE || + ctx->vol_sprite_usage == GMC_SPRITE)) { + if (mpeg4_decode_sprite_trajectory(ctx, gb) < 0) + return AVERROR_INVALIDDATA; + if (ctx->sprite_brightness_change) + av_log(s->avctx, AV_LOG_ERROR, + "sprite_brightness_change not supported\n"); + if (ctx->vol_sprite_usage == STATIC_SPRITE) + av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n"); + } else { + memset(s->sprite_offset, 0, sizeof(s->sprite_offset)); + memset(s->sprite_delta, 0, sizeof(s->sprite_delta)); + } } if (ctx->shape != BIN_ONLY_SHAPE) {