From a931e21715f22f08b54708c77906d67cfcf188e7 Mon Sep 17 00:00:00 2001
From: "Timothy B. Terriberry" <tterribe@xiph.org>
Date: Fri, 1 May 2020 19:01:41 -0700
Subject: [PATCH] Avoid a potential divide-by-zero.
Reported by clang's static analysis in
https://github.com/xiph/opusfile/issues/16
This would have taken about 22 TB of junk data before the first
decoded sample to trigger, so not very likely to occur in
practice.
Thanks to kcgen for filing the report.
---
src/opusfile.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/opusfile.c b/src/opusfile.c
index ed3a949..e9461ef 100644
--- a/src/opusfile.c
+++ b/src/opusfile.c
@@ -1782,6 +1782,7 @@ int op_current_link(const OggOpusFile *_of){
/*Compute an average bitrate given a byte and sample count.
Return: The bitrate in bits per second.*/
static opus_int32 op_calc_bitrate(opus_int64 _bytes,ogg_int64_t _samples){
+ if(OP_UNLIKELY(_samples<=0))return OP_INT32_MAX;
/*These rates are absurd, but let's handle them anyway.*/
if(OP_UNLIKELY(_bytes>(OP_INT64_MAX-(_samples>>1))/(48000*8))){
ogg_int64_t den;
@@ -1791,7 +1792,6 @@ static opus_int32 op_calc_bitrate(opus_int64 _bytes,ogg_int64_t _samples){
den=_samples/(48000*8);
return (opus_int32)((_bytes+(den>>1))/den);
}
- if(OP_UNLIKELY(_samples<=0))return OP_INT32_MAX;
/*This can't actually overflow in normal operation: even with a pre-skip of
545 2.5 ms frames with 8 streams running at 1282*8+1 bytes per packet
(1275 byte frames + Opus framing overhead + Ogg lacing values), that all
--
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