From 721624c2f67545989626ba4413f7b8dbd7dff678 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 5 Nov 2019 22:27:04 +0100 Subject: [PATCH] avcodec/ralf: Fix integer overflows with the filter coefficient in decode_channel() Fixes: signed integer overflow: 1145975808 - -1146173210 cannot be represented in type 'int' Fixes: 18616/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RALF_fuzzer-5121296757424128 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/ralf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavcodec/ralf.c b/libavcodec/ralf.c index ca8817aa21..d8f1803086 100644 --- a/libavcodec/ralf.c +++ b/libavcodec/ralf.c @@ -264,8 +264,8 @@ static int decode_channel(RALFContext *ctx, GetBitContext *gb, int ch, t = get_vlc2(gb, vlc[cmode].table, vlc[cmode].bits, 2); t = extend_code(gb, t, 21, add_bits); if (!cmode) - coeff -= 12 << add_bits; - coeff = t - coeff; + coeff -= 12U << add_bits; + coeff = (unsigned)t - coeff; ctx->filter[i] = coeff; cmode = coeff >> add_bits;