The netlink policy for TIPC_NLA_UDP_LOCAL and TIPC_NLA_UDP_REMOTE
is of type binary with a defined length. This causes the policy
framework to threat the defined length as maximum length.
There is however no protection against a user sending a smaller
amount of data. Prior to this patch this wasn't handled which could
result in a partially incomplete sockaddr_storage struct containing
uninitialized data.
In this patch we use nla_memcpy() when copying the user data. This
ensures a potential gap at the end is cleared out properly.
This was found by Julia with Coccinelle tool.
Reported-by: Daniel Borkmann <dan...@iogearbox.net>
Reported-by: Julia Lawall <julia.law...@lip6.fr>
Signed-off-by: Richard Alpe <richard.a...@ericsson.com>
Acked-by: Jon Maloy <jon.ma...@ericsson.com>
Reviewed-by: Erik Hugne <erik.hu...@gmail.com>
---
net/tipc/udp_media.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index f22a5bb1..6fe8740 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -276,7 +276,7 @@ static int parse_options(struct nlattr *attrs[], struct
udp_bearer *ub,
struct udp_media_addr *remote)
{
struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
- struct sockaddr_storage *sa_local, *sa_remote;
+ struct sockaddr_storage sa_local, sa_remote;
if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
goto err;
@@ -285,41 +285,43 @@ static int parse_options(struct nlattr *attrs[], struct
udp_bearer *ub,
tipc_nl_udp_policy))
goto err;
if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) {
- sa_local = nla_data(opts[TIPC_NLA_UDP_LOCAL]);
- sa_remote = nla_data(opts[TIPC_NLA_UDP_REMOTE]);
+ nla_memcpy(&sa_local, opts[TIPC_NLA_UDP_LOCAL],
+ sizeof(sa_local));
+ nla_memcpy(&sa_remote, opts[TIPC_NLA_UDP_REMOTE],
+ sizeof(sa_remote));
} else {
err:
pr_err("Invalid UDP bearer configuration");
return -EINVAL;
}
- if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET) {
+ if ((sa_local.ss_family & sa_remote.ss_family) == AF_INET) {
struct sockaddr_in *ip4;
- ip4 = (struct sockaddr_in *)sa_local;
+ ip4 = (struct sockaddr_in *)&sa_local;
local->proto = htons(ETH_P_IP);
local->udp_port = ip4->sin_port;
local->ipv4.s_addr = ip4->sin_addr.s_addr;
- ip4 = (struct sockaddr_in *)sa_remote;
+ ip4 = (struct sockaddr_in *)&sa_remote;
remote->proto = htons(ETH_P_IP);
remote->udp_port = ip4->sin_port;
remote->ipv4.s_addr = ip4->sin_addr.s_addr;
return 0;
#if IS_ENABLED(CONFIG_IPV6)
- } else if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET6) {
+ } else if ((sa_local.ss_family & sa_remote.ss_family) == AF_INET6) {
struct sockaddr_in6 *ip6;
- ip6 = (struct sockaddr_in6 *)sa_local;
+ ip6 = (struct sockaddr_in6 *)&sa_local;
local->proto = htons(ETH_P_IPV6);
local->udp_port = ip6->sin6_port;
- local->ipv6 = ip6->sin6_addr;
+ memcpy(&local->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
ub->ifindex = ip6->sin6_scope_id;
- ip6 = (struct sockaddr_in6 *)sa_remote;
+ ip6 = (struct sockaddr_in6 *)&sa_remote;
remote->proto = htons(ETH_P_IPV6);
remote->udp_port = ip6->sin6_port;
- remote->ipv6 = ip6->sin6_addr;
+ memcpy(&remote->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
return 0;
#endif
}
--
2.1.4
