[FFmpeg-devel] [PATCH 4/5] avcodec/apedec: Fix integer overflow in intermediate

Michael Niedermayer michael at niedermayer.cc
Wed Sep 15 23:00:47 EEST 2021


Fixes: signed integer overflow: 559334865 * 4 cannot be represented in type 'int'
Fixes: 37929/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-6751932295806976

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/apedec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index bf481ba3549..23318be0613 100644
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -1337,7 +1337,7 @@ static void do_apply_filter(APEContext *ctx, int version, APEFilter *f,
             absres = FFABSU(res);
             if (absres)
                 *f->adaptcoeffs = APESIGN(res) *
-                                  (8 << ((absres > f->avg * 3) + (absres > f->avg * 4 / 3)));
+                                  (8 << ((absres > f->avg * 3) + (absres > f->avg * 4LL / 3)));
                 /* equivalent to the following code
                     if (absres <= f->avg * 4 / 3)
                         *f->adaptcoeffs = APESIGN(res) * 8;
-- 
2.17.1



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