From d1992448d37f7cfa2acda5cc729dc0ff1b019390 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Tue, 13 Jun 2017 16:25:59 +0200
Subject: [PATCH] avcodec/aacsbr_fixed: Check shift in sbr_hf_assemble()
Fixes: runtime error: shift exponent -10 is negative
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
libavcodec/aacsbr_fixed.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/libavcodec/aacsbr_fixed.c b/libavcodec/aacsbr_fixed.c
index 269c9a2c881..2531637194b 100644
--- a/libavcodec/aacsbr_fixed.c
+++ b/libavcodec/aacsbr_fixed.c
@@ -575,22 +575,30 @@ static void sbr_hf_assemble(int Y1[38][64][2],
SoftFloat *in = sbr->s_m[e];
for (m = 0; m+1 < m_max; m+=2) {
+ int shift2;
shift = 22 - in[m ].exp;
+ shift2= 22 - in[m+1].exp;
+ if (shift < 1 || shift2 < 1) {
+ av_log(NULL, AV_LOG_ERROR, "Overflow in sbr_hf_assemble, shift=%d,%d\n", shift, shift2);
+ return;
+ }
if (shift < 32) {
round = 1 << (shift-1);
out[2*m ] += (in[m ].mant * A + round) >> shift;
}
- shift = 22 - in[m+1].exp;
- if (shift < 32) {
- round = 1 << (shift-1);
- out[2*m+2] += (in[m+1].mant * B + round) >> shift;
+ if (shift2 < 32) {
+ round = 1 << (shift2-1);
+ out[2*m+2] += (in[m+1].mant * B + round) >> shift2;
}
}
if(m_max&1)
{
shift = 22 - in[m ].exp;
- if (shift < 32) {
+ if (shift < 1) {
+ av_log(NULL, AV_LOG_ERROR, "Overflow in sbr_hf_assemble, shift=%d\n", shift);
+ return;
+ } else if (shift < 32) {
round = 1 << (shift-1);
out[2*m ] += (in[m ].mant * A + round) >> shift;
}
--
GitLab