Smack: IPv6 casting error fix for 3.11

The original implementation of the Smack IPv6 port based
local controls works most of the time using a sockaddr as
a temporary variable, but not always as it overflows in
some circumstances. The correct data is a sockaddr_in6.
A struct sockaddr isn't as large as a struct sockaddr_in6.
There would need to be casting one way or the other. This
patch gets it the right way.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>

1 files changed, 11 insertions, 13 deletions

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 3f7682a387b7..eefbd10e408f 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1998,12 +1998,11 @@ static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
  *
  * Create or update the port list entry
  */
-static int smk_ipv6_port_check(struct sock *sk, struct sockaddr *address,
+static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
                                 int act)
 {
         __be16 *bep;
         __be32 *be32p;
-        struct sockaddr_in6 *addr6;
         struct smk_port_label *spp;
         struct socket_smack *ssp = sk->sk_security;
         struct smack_known *skp;
@@ -2025,10 +2024,9 @@ static int smk_ipv6_port_check(struct sock *sk, struct sockaddr *address,
         /*
          * Get the IP address and port from the address.
          */
-        addr6 = (struct sockaddr_in6 *)address;
-        port = ntohs(addr6->sin6_port);
-        bep = (__be16 *)(&addr6->sin6_addr);
-        be32p = (__be32 *)(&addr6->sin6_addr);
+        port = ntohs(address->sin6_port);
+        bep = (__be16 *)(&address->sin6_addr);
+        be32p = (__be32 *)(&address->sin6_addr);
 
         /*
          * It's remote, so port lookup does no good.
@@ -2060,9 +2058,9 @@ auditout:
         ad.a.u.net->family = sk->sk_family;
         ad.a.u.net->dport = port;
         if (act == SMK_RECEIVING)
-                ad.a.u.net->v6info.saddr = addr6->sin6_addr;
+                ad.a.u.net->v6info.saddr = address->sin6_addr;
         else
-                ad.a.u.net->v6info.daddr = addr6->sin6_addr;
+                ad.a.u.net->v6info.daddr = address->sin6_addr;
 #endif
         return smk_access(skp, object, MAY_WRITE, &ad);
 }
@@ -2201,7 +2199,8 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
         case PF_INET6:
                 if (addrlen < sizeof(struct sockaddr_in6))
                         return -EINVAL;
-                rc = smk_ipv6_port_check(sock->sk, sap, SMK_CONNECTING);
+                rc = smk_ipv6_port_check(sock->sk, (struct sockaddr_in6 *)sap,
+                                                SMK_CONNECTING);
                 break;
         }
         return rc;
@@ -3034,7 +3033,7 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
                                 int size)
 {
         struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
-        struct sockaddr *sap = (struct sockaddr *) msg->msg_name;
+        struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
         int rc = 0;
 
         /*
@@ -3121,9 +3120,8 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
         return smack_net_ambient;
 }
 
-static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr *sap)
+static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
 {
-        struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;
         u8 nexthdr;
         int offset;
         int proto = -EINVAL;
@@ -3181,7 +3179,7 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
         struct netlbl_lsm_secattr secattr;
         struct socket_smack *ssp = sk->sk_security;
         struct smack_known *skp;
-        struct sockaddr sadd;
+        struct sockaddr_in6 sadd;
         int rc = 0;
         struct smk_audit_info ad;
 #ifdef CONFIG_AUDIT