[asterisk-commits] tilghman: branch 1.4 r168603 - /branches/1.4/main/udptl.c

[SVN commits to the Asterisk project]

Author: tilghman
Date: Wed Jan 14 13:02:55 2009
New Revision: 168603

URL: http://svn.digium.com/svn-view/asterisk?view=rev&rev=168603
Log:
Don't read into a buffer without first checking if a value is beyond the end.
(closes issue #13600)
 Reported by: atis
 Patches: 
       20090106__bug13600.diff.txt uploaded by Corydon76 (license 14)
 Tested by: atis

Modified:
    branches/1.4/main/udptl.c

Modified: branches/1.4/main/udptl.c
URL: http://svn.digium.com/svn-view/asterisk/branches/1.4/main/udptl.c?view=diff&rev=168603&r1=168602&r2=168603
==============================================================================
--- branches/1.4/main/udptl.c (original)
+++ branches/1.4/main/udptl.c Wed Jan 14 13:02:55 2009
@@ -156,15 +156,15 @@
 
 static int decode_length(uint8_t *buf, int limit, int *len, int *pvalue)
 {
+	if (*len >= limit)
+		return -1;
 	if ((buf[*len] & 0x80) == 0) {
-		if (*len >= limit)
-			return -1;
 		*pvalue = buf[*len];
 		(*len)++;
 		return 0;
 	}
 	if ((buf[*len] & 0x40) == 0) {
-		if (*len >= limit - 1)
+		if (*len == limit - 1)
 			return -1;
 		*pvalue = (buf[*len] & 0x3F) << 8;
 		(*len)++;
@@ -172,8 +172,6 @@
 		(*len)++;
 		return 0;
 	}
-	if (*len >= limit)
-		return -1;
 	*pvalue = (buf[*len] & 0x3F) << 14;
 	(*len)++;
 	/* Indicate we have a fragment */