From 7a072fbcc4c6f8ddbf37b131c2d141589118abcd Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 18 Jun 2019 14:28:17 +0200 Subject: avcodec/binkdsp: Fix integer overflows in idct Fixes: signed integer overflow: 3784 * 682038 cannot be represented in type 'int' Fixes: 15265/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BINK_fuzzer-5088311799971840 Fixes: 15268/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BINK_fuzzer-5666502344179712 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Reviewed-by: Reviewed-by: Peter Ross Signed-off-by: Michael Niedermayer --- libavcodec/binkdsp.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'libavcodec/binkdsp.c') diff --git a/libavcodec/binkdsp.c b/libavcodec/binkdsp.c index 9d70e2326f..a357d31672 100644 --- a/libavcodec/binkdsp.c +++ b/libavcodec/binkdsp.c @@ -33,20 +33,22 @@ #define A3 3784 #define A4 -5352 +#define MUL(X,Y) ((int)((unsigned)(X) * (Y)) >> 11) + #define IDCT_TRANSFORM(dest,s0,s1,s2,s3,s4,s5,s6,s7,d0,d1,d2,d3,d4,d5,d6,d7,munge,src) {\ const int a0 = (src)[s0] + (src)[s4]; \ const int a1 = (src)[s0] - (src)[s4]; \ const int a2 = (src)[s2] + (src)[s6]; \ - const int a3 = (A1*((src)[s2] - (src)[s6])) >> 11; \ + const int a3 = MUL(A1, (src)[s2] - (src)[s6]); \ const int a4 = (src)[s5] + (src)[s3]; \ const int a5 = (src)[s5] - (src)[s3]; \ const int a6 = (src)[s1] + (src)[s7]; \ const int a7 = (src)[s1] - (src)[s7]; \ const int b0 = a4 + a6; \ - const int b1 = (A3*(a5 + a7)) >> 11; \ - const int b2 = ((A4*a5) >> 11) - b0 + b1; \ - const int b3 = (A1*(a6 - a4) >> 11) - b2; \ - const int b4 = ((A2*a7) >> 11) + b3 - b1; \ + const int b1 = MUL(A3, a5 + a7); \ + const int b2 = MUL(A4, a5) - b0 + b1; \ + const int b3 = MUL(A1, a6 - a4) - b2; \ + const int b4 = MUL(A2, a7) + b3 - b1; \ (dest)[d0] = munge(a0+a2 +b0); \ (dest)[d1] = munge(a1+a3-a2+b2); \ (dest)[d2] = munge(a1-a3+a2+b3); \ -- cgit v1.2.1