avcodec/interplayacm: Fix overflow of last unused value
authorMichael Niedermayer <michael@niedermayer.cc>
Fri, 25 Oct 2019 10:44:45 +0000 (12:44 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Sat, 9 Nov 2019 17:03:38 +0000 (18:03 +0100)
Fixes: signed integer overflow: -2147450880 - 65535 cannot be represented in type 'int'
Fixes: 18393/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_INTERPLAY_ACM_fuzzer-5667520110919680

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/interplayacm.c

index cff79eb..3704d1a 100644 (file)
@@ -529,7 +529,7 @@ static int decode_block(InterplayACMContext *s)
 
     for (i = 1, x = -val; i <= count; i++) {
         s->midbuf[-i] = x;
-        x -= val;
+        x -= (unsigned)val;
     }
 
     ret = fill_block(s);