[FFmpeg-devel] [PATCH 2/2] avcodec/sonic: Use unsigned for predictor_k to avoid undefined behavior

Michael Niedermayer michael at niedermayer.cc
Tue Feb 8 16:53:18 EET 2022


Fixes: signed integer overflow: -1094995529 * 24 cannot be represented in type 'int'
Fixes: 44436/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SONIC_fuzzer-4874459459223552

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/sonic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/sonic.c b/libavcodec/sonic.c
index cf1cfb1460..0d539e8879 100644
--- a/libavcodec/sonic.c
+++ b/libavcodec/sonic.c
@@ -1004,7 +1004,7 @@ static int sonic_decode_frame(AVCodecContext *avctx,
 
     // dequantize
     for (i = 0; i < s->num_taps; i++)
-        s->predictor_k[i] *= s->tap_quant[i];
+        s->predictor_k[i] *= (unsigned) s->tap_quant[i];
 
     if (s->lossless)
         quant = 1;
-- 
2.17.1



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