avoid endless loop in processipcp, processipv6cp

diff --git a/Changes b/Changes
index d4c668c..24b0c8c 100644 (file)
--- a/Changes
+++ b/Changes
@@ -4,6 +4,7 @@
 - Handle LCP NAK of magic-number.
 - Ensure session changes from LCP ConfigReq/ConfigNak are sent to cluster.
 - Verify that RADIUS packets come from a configured server (Jonathan Yarden).
+- Avoid endless loop in processipcp, processipv6cp.
 
 * Mon Dec 19 2005 Brendan O'Dea <bod@optus.net> 2.1.15
 - Drop backtrace.

diff --git a/ppp.c b/ppp.c
index 0f6bba9..b306f28 100644 (file)
--- a/ppp.c
+++ b/ppp.c
@@ -1,6 +1,6 @@
 // L2TPNS PPP Stuff
 
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.94 2006-01-19 21:31:25 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.95 2006-02-17 14:35:54 bodea Exp $";
 
 #include <stdio.h>
 #include <string.h>
@@ -1014,11 +1014,13 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                while (length > 2)
                {
+                       if (!o[1] || o[1] > length) return;
+
                        switch (*o)
                        {
                        case 3: // ip address
                                gotip++; // seen address
-                               if (o[1] != 6 || o[1] > length) return;
+                               if (o[1] != 6) return;
 
                                addr = htonl(session[s].ip);
                                if (memcmp(o + 2, &addr, (sizeof addr)))
@@ -1035,7 +1037,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                break;
 
                        case 129: // primary DNS
-                               if (o[1] != 6 || o[1] > length) return;
+                               if (o[1] != 6) return;
 
                                addr = htonl(session[s].dns1);
                                if (memcmp(o + 2, &addr, (sizeof addr)))
@@ -1047,7 +1049,7 @@ void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
                                break;
 
                        case 131: // secondary DNS
-                               if (o[1] != 6 || o[1] > length) return;
+                               if (o[1] != 6) return;
 
                                addr = htonl(session[s].dns2);
                                if (memcmp(o + 2, &addr, sizeof(addr)))
@@ -1239,11 +1241,13 @@ void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
 
                while (length > 2)
                {
+                       if (!o[1] || o[1] > length) return;
+
                        switch (*o)
                        {
                        case 1: // interface identifier
                                gotip++; // seen address
-                               if (o[1] != 10 || o[1] > length) return;
+                               if (o[1] != 10) return;
 
                                *(uint32_t *) ident = htonl(session[s].ip);
                                *(uint32_t *) (ident + 4) = 0;