From aa2b75263e17651187b1475551a02aa2f4ff65fe Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 19 Feb 2017 21:33:27 +0100 Subject: avcodec/mpeg4videodec: Fix runtime error: shift exponent -2 is negative Fixes: 612/clusterfuzz-testcase-4707817137111040 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/mpeg4videodec.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'libavcodec') diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c index 0e549ef116..58ae05f8ff 100644 --- a/libavcodec/mpeg4videodec.c +++ b/libavcodec/mpeg4videodec.c @@ -367,6 +367,12 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g } else { int shift_y = 16 - ctx->sprite_shift[0]; int shift_c = 16 - ctx->sprite_shift[1]; + + if (shift_c < 0 || shift_y < 0) { + avpriv_request_sample(s->avctx, "Too large sprite shift"); + return AVERROR_PATCHWELCOME; + } + for (i = 0; i < 2; i++) { s->sprite_offset[0][i] *= 1 << shift_y; s->sprite_offset[1][i] *= 1 << shift_c; -- cgit v1.2.3