From d8b4852e45a94fcde141ae28a2d5e36368ca92ae Mon Sep 17 00:00:00 2001
From: Michal Sekletar <msekleta@redhat.com>
Date: Thu, 20 Nov 2014 11:38:46 +0100
Subject: [PATCH] Do more bounds checking and length checking.
Don't run past the end of the captured data, and don't run past the end
of the packet (i.e., don't make the length variable go negative).
Also, stop dissecting if the message length isn't valid.
(cherry picked from commit 4038f83ebf654804829b258dde5e0a508c1c2003)
---
print-olsr.c | 56 +++++++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 43 insertions(+), 13 deletions(-)
diff --git a/print-olsr.c b/print-olsr.c
index d8619d4..f586d80 100644
--- a/print-olsr.c
+++ b/print-olsr.c
@@ -181,7 +181,7 @@ struct olsr_lq_neighbor6 {
/*
* print a neighbor list with LQ extensions.
*/
-static void
+static int
olsr_print_lq_neighbor4 (const u_char *msg_data, u_int hello_len)
{
struct olsr_lq_neighbor4 *lq_neighbor;
@@ -189,6 +189,8 @@ olsr_print_lq_neighbor4 (const u_char *msg_data, u_int hello_len)
while (hello_len >= sizeof(struct olsr_lq_neighbor4)) {
lq_neighbor = (struct olsr_lq_neighbor4 *)msg_data;
+ if (!TTEST(*lq_neighbor))
+ return (-1);
printf("\n\t neighbor %s, link-quality %.2lf%%"
", neighbor-link-quality %.2lf%%",
@@ -199,10 +201,11 @@ olsr_print_lq_neighbor4 (const u_char *msg_data, u_int hello_len)
msg_data += sizeof(struct olsr_lq_neighbor4);
hello_len -= sizeof(struct olsr_lq_neighbor4);
}
+ return (0);
}
#if INET6
-static void
+static int
olsr_print_lq_neighbor6 (const u_char *msg_data, u_int hello_len)
{
struct olsr_lq_neighbor6 *lq_neighbor;
@@ -210,6 +213,8 @@ olsr_print_lq_neighbor6 (const u_char *msg_data, u_int hello_len)
while (hello_len >= sizeof(struct olsr_lq_neighbor6)) {
lq_neighbor = (struct olsr_lq_neighbor6 *)msg_data;
+ if (!TTEST(*lq_neighbor))
+ return (-1);
printf("\n\t neighbor %s, link-quality %.2lf%%"
", neighbor-link-quality %.2lf%%",
@@ -220,13 +225,14 @@ olsr_print_lq_neighbor6 (const u_char *msg_data, u_int hello_len)
msg_data += sizeof(struct olsr_lq_neighbor6);
hello_len -= sizeof(struct olsr_lq_neighbor6);
}
+ return (0);
}
#endif /* INET6 */
/*
* print a neighbor list.
*/
-static void
+static int
olsr_print_neighbor (const u_char *msg_data, u_int hello_len)
{
int neighbor;
@@ -236,6 +242,9 @@ olsr_print_neighbor (const u_char *msg_data, u_int hello_len)
while (hello_len >= sizeof(struct in_addr)) {
+ if (!TTEST2(*msg_data, sizeof(struct in_addr)))
+ return (-1);
+
/* print 4 neighbors per line */
printf("%s%s", ipaddr_string(msg_data),
@@ -329,6 +338,9 @@ olsr_print (const u_char *pptr, u_int length, int is_ipv6)
ME_TO_DOUBLE(msgptr.v6->vtime),
EXTRACT_16BITS(msgptr.v6->msg_seq),
msg_len, (msg_len_valid == 0) ? " (invalid)" : "");
+ if (!msg_len_valid) {
+ return;
+ }
msg_tlen = msg_len - sizeof(struct olsr_msg6);
msg_data = tptr + sizeof(struct olsr_msg6);
@@ -357,6 +369,9 @@ olsr_print (const u_char *pptr, u_int length, int is_ipv6)
ME_TO_DOUBLE(msgptr.v4->vtime),
EXTRACT_16BITS(msgptr.v4->msg_seq),
msg_len, (msg_len_valid == 0) ? " (invalid)" : "");
+ if (!msg_len_valid) {
+ return;
+ }
msg_tlen = msg_len - sizeof(struct olsr_msg4);
msg_data = tptr + sizeof(struct olsr_msg4);
@@ -365,6 +380,8 @@ olsr_print (const u_char *pptr, u_int length, int is_ipv6)
switch (msg_type) {
case OLSR_HELLO_MSG:
case OLSR_HELLO_LQ_MSG:
+ if (msg_tlen < sizeof(struct olsr_hello))
+ goto trunc;
if (!TTEST2(*msg_data, sizeof(struct olsr_hello)))
goto trunc;
@@ -406,15 +423,21 @@ olsr_print (const u_char *pptr, u_int length, int is_ipv6)
msg_tlen -= sizeof(struct olsr_hello_link);
hello_len -= sizeof(struct olsr_hello_link);
+ TCHECK2(*msg_data, hello_len);
if (msg_type == OLSR_HELLO_MSG) {
- olsr_print_neighbor(msg_data, hello_len);
+ if (olsr_print_neighbor(msg_data, hello_len) == -1)
+ goto trunc;
} else {
#if INET6
- if (is_ipv6)
- olsr_print_lq_neighbor6(msg_data, hello_len);
- else
+ if (is_ipv6) {
+ if (olsr_print_lq_neighbor6(msg_data, hello_len) == -1)
+ goto trunc;
+ } else
#endif
- olsr_print_lq_neighbor4(msg_data, hello_len);
+ {
+ if (olsr_print_lq_neighbor4(msg_data, hello_len) == -1)
+ goto trunc;
+ }
}
msg_data += hello_len;
@@ -424,6 +447,8 @@ olsr_print (const u_char *pptr, u_int length, int is_ipv6)
case OLSR_TC_MSG:
case OLSR_TC_LQ_MSG:
+ if (msg_tlen < sizeof(struct olsr_tc))
+ goto trunc;
if (!TTEST2(*msg_data, sizeof(struct olsr_tc)))
goto trunc;
@@ -434,14 +459,19 @@ olsr_print (const u_char *pptr, u_int length, int is_ipv6)
msg_tlen -= sizeof(struct olsr_tc);
if (msg_type == OLSR_TC_MSG) {
- olsr_print_neighbor(msg_data, msg_tlen);
+ if (olsr_print_neighbor(msg_data, msg_tlen) == -1)
+ goto trunc;
} else {
#if INET6
- if (is_ipv6)
- olsr_print_lq_neighbor6(msg_data, msg_tlen);
- else
+ if (is_ipv6) {
+ if (olsr_print_lq_neighbor6(msg_data, msg_tlen) == -1)
+ goto trunc;
+ } else
#endif
- olsr_print_lq_neighbor4(msg_data, msg_tlen);
+ {
+ if (olsr_print_lq_neighbor4(msg_data, msg_tlen) == -1)
+ goto trunc;
+ }
}
break;
--
1.8.3.1