From 76ba09d18245a2a41dc5f93a60fd00cdf358cb1f Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 23 Feb 2017 22:33:16 +0100 Subject: [PATCH] avcodec/mpeg4videodec: Check the other 3 sprite points for intermediate overflows This is not necessarily specific to fuzzed files Fixes: Multiple integer overflows Fixes: 656/clusterfuzz-testcase-6463814516080640 Fixes: 658/clusterfuzz-testcase-6691260146384896 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/mpeg4videodec.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c index 2216cd56e8..dac9538436 100644 --- a/libavcodec/mpeg4videodec.c +++ b/libavcodec/mpeg4videodec.c @@ -384,6 +384,13 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g s->sprite_delta[0][i] *= 1 << shift_y; s->sprite_delta[1][i] *= 1 << shift_y; ctx->sprite_shift[i] = 16; + + if (llabs(s->sprite_offset[i][0] + s->sprite_delta[i][0] * (int64_t)w) >= INT_MAX || + llabs(s->sprite_offset[i][0] + s->sprite_delta[i][1] * (int64_t)h) >= INT_MAX || + llabs(s->sprite_offset[i][0] + s->sprite_delta[i][0] * (int64_t)w + s->sprite_delta[i][1] * (int64_t)h) >= INT_MAX) { + avpriv_request_sample(s->avctx, "Overflow on sprite points"); + return AVERROR_PATCHWELCOME; + } } s->real_sprite_warping_points = ctx->num_sprite_warping_points; }