From 99696ad046e5b1ae2d5dc03fad918db7b9f23961 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Wed, 22 Feb 2017 01:22:24 +0100
Subject: [PATCH] avcodec/mpeg4video: Fix runtime error: left shift of negative
value
Fixes: 644/clusterfuzz-testcase-4726434209726464
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 6179dc8aa7e5fc5358b9614306f93f1adadf22a4)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
libavcodec/mpeg4videodec.c | 2 +-
libavcodec/mpegvideo_motion.c | 8 ++++----
2 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
index e9353aab5d..448dfaf179 100644
--- a/libavcodec/mpeg4videodec.c
+++ b/libavcodec/mpeg4videodec.c
@@ -509,7 +509,7 @@ static inline int get_amv(Mpeg4DecContext *ctx, int n)
if (ctx->divx_version == 500 && ctx->divx_build == 413)
sum = s->sprite_offset[0][n] / (1 << (a - s->quarter_sample));
else
- sum = RSHIFT(s->sprite_offset[0][n] << s->quarter_sample, a);
+ sum = RSHIFT(s->sprite_offset[0][n] * (1 << s->quarter_sample), a);
} else {
dx = s->sprite_delta[n][0];
dy = s->sprite_delta[n][1];
diff --git a/libavcodec/mpegvideo_motion.c b/libavcodec/mpegvideo_motion.c
index 51ba435231..2d3a778ec4 100644
--- a/libavcodec/mpegvideo_motion.c
+++ b/libavcodec/mpegvideo_motion.c
@@ -48,8 +48,8 @@ static void gmc1_motion(MpegEncContext *s,
motion_y = s->sprite_offset[0][1];
src_x = s->mb_x * 16 + (motion_x >> (s->sprite_warping_accuracy + 1));
src_y = s->mb_y * 16 + (motion_y >> (s->sprite_warping_accuracy + 1));
- motion_x <<= (3 - s->sprite_warping_accuracy);
- motion_y <<= (3 - s->sprite_warping_accuracy);
+ motion_x *= 1 << (3 - s->sprite_warping_accuracy);
+ motion_y *= 1 << (3 - s->sprite_warping_accuracy);
src_x = av_clip(src_x, -16, s->width);
if (src_x == s->width)
motion_x = 0;
@@ -95,8 +95,8 @@ static void gmc1_motion(MpegEncContext *s,
motion_y = s->sprite_offset[1][1];
src_x = s->mb_x * 8 + (motion_x >> (s->sprite_warping_accuracy + 1));
src_y = s->mb_y * 8 + (motion_y >> (s->sprite_warping_accuracy + 1));
- motion_x <<= (3 - s->sprite_warping_accuracy);
- motion_y <<= (3 - s->sprite_warping_accuracy);
+ motion_x *= 1 << (3 - s->sprite_warping_accuracy);
+ motion_y *= 1 << (3 - s->sprite_warping_accuracy);
src_x = av_clip(src_x, -8, s->width >> 1);
if (src_x == s->width >> 1)
motion_x = 0;