fixes infinite loop during udptl.c's decode_open_type

When decode_length returns the length there is a check to see if that
length is negative, if so the decode loop breaks as this means the
limit has been reached.  The problem here is that length is an
unsigned int, so length can never be negative.  This resulted in
an infinite loop.

(issue #17352)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@264400 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/main/udptl.c b/main/udptl.c
index 0e88b2b..113a183 100644 (file)
--- a/main/udptl.c
+++ b/main/udptl.c
@@ -226,8 +226,8 @@ static int decode_open_type(uint8_t *buf, unsigned int limit, unsigned int *len,
 {
        unsigned int octet_cnt;
        unsigned int octet_idx;
-       unsigned int length;
        unsigned int i;
+       int length; /* a negative length indicates the limit has been reached in decode_length. */
        const uint8_t **pbuf;
 
        for (octet_idx = 0, *p_num_octets = 0; ; octet_idx += octet_cnt) {