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tipc: safely copy UDP netlink data from user 

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 <daniel@iogearbox.net>
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Richard Alpe 2016-03-03 14:20:42 +01:00 committed by David S. Miller
parent 2837f39c7c
commit ddb3712552
1 changed files with 13 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
net/tipc/udp_media.c
View File

@ -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
}