From dce80a4b47efaba97707bda781a9ee57f5a26974 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 3 Jun 2018 00:48:06 +0200 Subject: [PATCH] avcodec/amrwbdec: Fix division by 0 in find_hb_gain() This restructures the code slightly toward D_UTIL_dec_synthesis() Fixes: 7420/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AMRWB_fuzzer-6577305112543232 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/amrwbdec.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/libavcodec/amrwbdec.c b/libavcodec/amrwbdec.c index 7f2874d35f..47fe7eb55e 100644 --- a/libavcodec/amrwbdec.c +++ b/libavcodec/amrwbdec.c @@ -862,15 +862,20 @@ static float find_hb_gain(AMRWBContext *ctx, const float *synth, { int wsp = (vad > 0); float tilt; + float tmp; if (ctx->fr_cur_mode == MODE_23k85) return qua_hb_gain[hb_idx] * (1.0f / (1 << 14)); - tilt = ctx->celpm_ctx.dot_productf(synth, synth + 1, AMRWB_SFR_SIZE - 1) / - ctx->celpm_ctx.dot_productf(synth, synth, AMRWB_SFR_SIZE); + tmp = ctx->celpm_ctx.dot_productf(synth, synth + 1, AMRWB_SFR_SIZE - 1); + + if (tmp > 0) { + tilt = tmp / ctx->celpm_ctx.dot_productf(synth, synth, AMRWB_SFR_SIZE); + } else + tilt = 0; /* return gain bounded by [0.1, 1.0] */ - return av_clipf((1.0 - FFMAX(0.0, tilt)) * (1.25 - 0.25 * wsp), 0.1, 1.0); + return av_clipf((1.0 - tilt) * (1.25 - 0.25 * wsp), 0.1, 1.0); } /**