1 files changed, 77 insertions, 49 deletions

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index b9c5e149903b..fb915163f967 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -516,6 +516,8 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
                                      const struct qstr *qstr, char **name,
                                      void **value, size_t *len)
 {
+        struct smack_known *skp;
+        char *csp = smk_of_current();
         char *isp = smk_of_inode(inode);
         char *dsp = smk_of_inode(dir);
         int may;
@@ -527,8 +529,9 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
         }
 
         if (value) {
+                skp = smk_find_entry(csp);
                 rcu_read_lock();
-                may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list);
+                may = smk_access_entry(csp, dsp, &skp->smk_rules);
                 rcu_read_unlock();
 
                 /*
@@ -1138,6 +1141,7 @@ static int smack_file_mmap(struct file *file,
                            unsigned long flags, unsigned long addr,
                            unsigned long addr_only)
 {
+        struct smack_known *skp;
         struct smack_rule *srp;
         struct task_smack *tsp;
         char *sp;
@@ -1170,6 +1174,7 @@ static int smack_file_mmap(struct file *file,
 
         tsp = current_security();
         sp = smk_of_current();
+        skp = smk_find_entry(sp);
         rc = 0;
 
         rcu_read_lock();
@@ -1177,15 +1182,8 @@ static int smack_file_mmap(struct file *file,
          * For each Smack rule associated with the subject
          * label verify that the SMACK64MMAP also has access
          * to that rule's object label.
-         *
-         * Because neither of the labels comes
-         * from the networking code it is sufficient
-         * to compare pointers.
          */
-        list_for_each_entry_rcu(srp, &smack_rule_list, list) {
-                if (srp->smk_subject != sp)
-                        continue;
-
+        list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
                 osmack = srp->smk_object;
                 /*
                  * Matching labels always allows access.
@@ -1214,7 +1212,8 @@ static int smack_file_mmap(struct file *file,
                  * If there isn't one a SMACK64MMAP subject
                  * can't have as much access as current.
                  */
-                mmay = smk_access_entry(msmack, osmack, &smack_rule_list);
+                skp = smk_find_entry(msmack);
+                mmay = smk_access_entry(msmack, osmack, &skp->smk_rules);
                 if (mmay == -ENOENT) {
                         rc = -EACCES;
                         break;
@@ -1711,7 +1710,7 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
 
         ssp->smk_in = csp;
         ssp->smk_out = csp;
-        ssp->smk_packet[0] = '\0';
+        ssp->smk_packet = NULL;
 
         sk->sk_security = ssp;
 
@@ -2813,16 +2812,17 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
         return smack_netlabel_send(sock->sk, sip);
 }
 
-
 /**
  * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
  * @sap: netlabel secattr
- * @sip: where to put the result
+ * @ssp: socket security information
  *
- * Copies a smack label into sip
+ * Returns a pointer to a Smack label found on the label list.
  */
-static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
+static char *smack_from_secattr(struct netlbl_lsm_secattr *sap,
+                                struct socket_smack *ssp)
 {
+        struct smack_known *skp;
         char smack[SMK_LABELLEN];
         char *sp;
         int pcat;
@@ -2852,15 +2852,43 @@ static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
                  * we are already done. WeeHee.
                  */
                 if (sap->attr.mls.lvl == smack_cipso_direct) {
-                        memcpy(sip, smack, SMK_MAXLEN);
-                        return;
+                        /*
+                         * The label sent is usually on the label list.
+                         *
+                         * If it is not we may still want to allow the
+                         * delivery.
+                         *
+                         * If the recipient is accepting all packets
+                         * because it is using the star ("*") label
+                         * for SMACK64IPIN provide the web ("@") label
+                         * so that a directed response will succeed.
+                         * This is not very correct from a MAC point
+                         * of view, but gets around the problem that
+                         * locking prevents adding the newly discovered
+                         * label to the list.
+                         * The case where the recipient is not using
+                         * the star label should obviously fail.
+                         * The easy way to do this is to provide the
+                         * star label as the subject label.
+                         */
+                        skp = smk_find_entry(smack);
+                        if (skp != NULL)
+                                return skp->smk_known;
+                        if (ssp != NULL &&
+                            ssp->smk_in == smack_known_star.smk_known)
+                                return smack_known_web.smk_known;
+                        return smack_known_star.smk_known;
                 }
                 /*
                  * Look it up in the supplied table if it is not
                  * a direct mapping.
                  */
-                smack_from_cipso(sap->attr.mls.lvl, smack, sip);
-                return;
+                sp = smack_from_cipso(sap->attr.mls.lvl, smack);
+                if (sp != NULL)
+                        return sp;
+                if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known)
+                        return smack_known_web.smk_known;
+                return smack_known_star.smk_known;
         }
         if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
                 /*
@@ -2875,16 +2903,14 @@ static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
                  * secid is from a fallback.
                  */
                 BUG_ON(sp == NULL);
-                strncpy(sip, sp, SMK_MAXLEN);
-                return;
+                return sp;
         }
         /*
          * Without guidance regarding the smack value
          * for the packet fall back on the network
          * ambient value.
          */
-        strncpy(sip, smack_net_ambient, SMK_MAXLEN);
-        return;
+        return smack_net_ambient;
 }
 
 /**
@@ -2898,7 +2924,6 @@ 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;
-        char smack[SMK_LABELLEN];
         char *csp;
         int rc;
         struct smk_audit_info ad;
@@ -2911,10 +2936,9 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
         netlbl_secattr_init(&secattr);
 
         rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
-        if (rc == 0) {
-                smack_from_secattr(&secattr, smack);
-                csp = smack;
-        } else
+        if (rc == 0)
+                csp = smack_from_secattr(&secattr, ssp);
+        else
                 csp = smack_net_ambient;
 
         netlbl_secattr_destroy(&secattr);
@@ -2951,15 +2975,19 @@ static int smack_socket_getpeersec_stream(struct socket *sock,
                                           int __user *optlen, unsigned len)
 {
         struct socket_smack *ssp;
-        int slen;
+        char *rcp = "";
+        int slen = 1;
         int rc = 0;
 
         ssp = sock->sk->sk_security;
-        slen = strlen(ssp->smk_packet) + 1;
+        if (ssp->smk_packet != NULL) {
+                rcp = ssp->smk_packet;
+                slen = strlen(rcp) + 1;
+        }
 
         if (slen > len)
                 rc = -ERANGE;
-        else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
+        else if (copy_to_user(optval, rcp, slen) != 0)
                 rc = -EFAULT;
 
         if (put_user(slen, optlen) != 0)
@@ -2982,8 +3010,8 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
 
 {
         struct netlbl_lsm_secattr secattr;
-        struct socket_smack *sp;
-        char smack[SMK_LABELLEN];
+        struct socket_smack *ssp = NULL;
+        char *sp;
         int family = PF_UNSPEC;
         u32 s = 0;      /* 0 is the invalid secid */
         int rc;
@@ -2998,17 +3026,19 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
                 family = sock->sk->sk_family;
 
         if (family == PF_UNIX) {
-                sp = sock->sk->sk_security;
-                s = smack_to_secid(sp->smk_out);
+                ssp = sock->sk->sk_security;
+                s = smack_to_secid(ssp->smk_out);
         } else if (family == PF_INET || family == PF_INET6) {
                 /*
                  * Translate what netlabel gave us.
                  */
+                if (sock != NULL && sock->sk != NULL)
+                        ssp = sock->sk->sk_security;
                 netlbl_secattr_init(&secattr);
                 rc = netlbl_skbuff_getattr(skb, family, &secattr);
                 if (rc == 0) {
-                        smack_from_secattr(&secattr, smack);
-                        s = smack_to_secid(smack);
+                        sp = smack_from_secattr(&secattr, ssp);
+                        s = smack_to_secid(sp);
                 }
                 netlbl_secattr_destroy(&secattr);
         }
@@ -3056,7 +3086,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
         struct netlbl_lsm_secattr secattr;
         struct sockaddr_in addr;
         struct iphdr *hdr;
-        char smack[SMK_LABELLEN];
+        char *sp;
         int rc;
         struct smk_audit_info ad;
 
@@ -3067,9 +3097,9 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
         netlbl_secattr_init(&secattr);
         rc = netlbl_skbuff_getattr(skb, family, &secattr);
         if (rc == 0)
-                smack_from_secattr(&secattr, smack);
+                sp = smack_from_secattr(&secattr, ssp);
         else
-                strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
+                sp = smack_known_huh.smk_known;
         netlbl_secattr_destroy(&secattr);
 
 #ifdef CONFIG_AUDIT
@@ -3082,7 +3112,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
          * Receiving a packet requires that the other end be able to write
          * here. Read access is not required.
          */
-        rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad);
+        rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad);
         if (rc != 0)
                 return rc;
 
@@ -3090,7 +3120,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
          * Save the peer's label in the request_sock so we can later setup
          * smk_packet in the child socket so that SO_PEERCRED can report it.
          */
-        req->peer_secid = smack_to_secid(smack);
+        req->peer_secid = smack_to_secid(sp);
 
         /*
          * We need to decide if we want to label the incoming connection here
@@ -3103,7 +3133,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
         if (smack_host_label(&addr) == NULL) {
                 rcu_read_unlock();
                 netlbl_secattr_init(&secattr);
-                smack_to_secattr(smack, &secattr);
+                smack_to_secattr(sp, &secattr);
                 rc = netlbl_req_setattr(req, &secattr);
                 netlbl_secattr_destroy(&secattr);
         } else {
@@ -3125,13 +3155,11 @@ static void smack_inet_csk_clone(struct sock *sk,
                                  const struct request_sock *req)
 {
         struct socket_smack *ssp = sk->sk_security;
-        char *smack;
 
-        if (req->peer_secid != 0) {
-                smack = smack_from_secid(req->peer_secid);
-                strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
-        } else
-                ssp->smk_packet[0] = '\0';
+        if (req->peer_secid != 0)
+                ssp->smk_packet = smack_from_secid(req->peer_secid);
+        else
+                ssp->smk_packet = NULL;
 }
 
 /*