From a6553d7db2083b2588c547124bcd32bbfb8e83e4 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 10 May 2020 20:15:11 +0200 Subject: [PATCH] avcodec/ralf: Fix integer overflow in decode_block() Fixes: signed integer overflow: 289082077 - -2003141111 cannot be represented in type 'int' Fixes: 20492/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RALF_fuzzer-5196077752123392 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 0c4330847c104fcf3ef929c1acee33b5b34c20db) Signed-off-by: Michael Niedermayer --- libavcodec/ralf.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/libavcodec/ralf.c b/libavcodec/ralf.c index 15be19b526..a57966a298 100644 --- a/libavcodec/ralf.c +++ b/libavcodec/ralf.c @@ -344,7 +344,8 @@ static int decode_block(AVCodecContext *avctx, GetBitContext *gb, int len, ch, ret; int dmode, mode[2], bits[2]; int *ch0, *ch1; - int i, t, t2; + int i; + unsigned int t, t2; len = 12 - get_unary(gb, 0, 6); @@ -409,8 +410,8 @@ static int decode_block(AVCodecContext *avctx, GetBitContext *gb, for (i = 0; i < len; i++) { t = ch1[i] + ctx->bias[1]; t2 = ((ch0[i] + ctx->bias[0]) * 2) | (t & 1); - dst0[i] = (t2 + t) / 2; - dst1[i] = (t2 - t) / 2; + dst0[i] = (int)(t2 + t) / 2; + dst1[i] = (int)(t2 - t) / 2; } break; }