Every time we call add_dns[46] we need to first check if there's space in
the c->ip[46].dns array for the new entry. We might as well make that
check in add_dns[46]() itself.
In fact it looks like the calls in get_dns() had an off by one error, not
allowing the last entry of the array to be filled. So, that bug is also
fixed by the change.
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>
---
conf.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/conf.c b/conf.c
index db036a75..a651cb91 100644
--- a/conf.c
+++ b/conf.c
@@ -363,6 +363,9 @@ static unsigned add_dns4(struct ctx *c, const struct in_addr *addr,
{
unsigned added = 0;
+ if (idx >= ARRAY_SIZE(c->ip4.dns))
+ return 0;
+
/* Guest or container can only access local addresses via redirect */
if (IN4_IS_ADDR_LOOPBACK(addr)) {
if (!c->no_map_gw) {
@@ -395,6 +398,9 @@ static unsigned add_dns6(struct ctx *c, struct in6_addr *addr,
unsigned idx)
{
unsigned added = 0;
+ if (idx >= ARRAY_SIZE(c->ip6.dns))
+ return 0;
+
/* Guest or container can only access local addresses via redirect */
if (IN6_IS_ADDR_LOOPBACK(addr)) {
if (!c->no_map_gw) {
@@ -453,12 +459,10 @@ static void get_dns(struct ctx *c)
if (end)
*end = 0;
- if (!dns4_set && dns4_idx < ARRAY_SIZE(c->ip4.dns) - 1
- && inet_pton(AF_INET, p + 1, &dns4_tmp))
+ if (!dns4_set && inet_pton(AF_INET, p + 1, &dns4_tmp))
dns4_idx += add_dns4(c, &dns4_tmp, dns4_idx);
- if (!dns6_set && dns6_idx < ARRAY_SIZE(c->ip6.dns) - 1
- && inet_pton(AF_INET6, p + 1, &dns6_tmp))
+ if (!dns6_set && inet_pton(AF_INET6, p + 1, &dns6_tmp))
dns6_idx += add_dns6(c, &dns6_tmp, dns6_idx);
} else if (!dnss_set && strstr(line, "search ") == line &&
s == c->dns_search) {
@@ -1682,14 +1686,12 @@ void conf(struct ctx *c, int argc, char **argv)
c->no_dns = 0;
- if (dns4_idx < ARRAY_SIZE(c->ip4.dns) &&
- inet_pton(AF_INET, optarg, &dns4_tmp)) {
+ if (inet_pton(AF_INET, optarg, &dns4_tmp)) {
dns4_idx += add_dns4(c, &dns4_tmp, dns4_idx);
continue;
}
- if (dns6_idx < ARRAY_SIZE(c->ip6.dns) &&
- inet_pton(AF_INET6, optarg, &dns6_tmp)) {
+ if (inet_pton(AF_INET6, optarg, &dns6_tmp)) {
dns6_idx += add_dns6(c, &dns6_tmp, dns6_idx);
continue;
}
--
2.46.0