[FFmpeg-cvslog] avcodec/mpeg4videodec: Fix runtime error: signed integer overflow: 134527392 * 16 cannot be represented in type 'int'

Michael Niedermayer git at videolan.org
Sun Mar 5 14:21:26 EET 2017


ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Fri Mar  3 20:12:20 2017 +0100| [fab13bbbcdf92da165f1a6be94fbb8f87fac639a] | committer: Michael Niedermayer

avcodec/mpeg4videodec: Fix runtime error: signed integer overflow: 134527392 * 16 cannot be represented in type 'int'

This checks the sprite delta intermediates for overflow
Fixes: 716/clusterfuzz-testcase-4890287480504320

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=fab13bbbcdf92da165f1a6be94fbb8f87fac639a
---

 libavcodec/mpeg4videodec.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
index 568263e..128469d 100644
--- a/libavcodec/mpeg4videodec.c
+++ b/libavcodec/mpeg4videodec.c
@@ -389,7 +389,10 @@ static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *g
         for (i = 0; i < 2; i++) {
             if (llabs(s->sprite_offset[0][i] + s->sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
                 llabs(s->sprite_offset[0][i] + s->sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
-                llabs(s->sprite_offset[0][i] + s->sprite_delta[i][0] * (w+16LL) + s->sprite_delta[i][1] * (h+16LL)) >= INT_MAX) {
+                llabs(s->sprite_offset[0][i] + s->sprite_delta[i][0] * (w+16LL) + s->sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
+                llabs(s->sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
+                llabs(s->sprite_delta[i][1] * (w+16LL)) >= INT_MAX
+            ) {
                 avpriv_request_sample(s->avctx, "Overflow on sprite points");
                 goto overflow;
             }



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