Fix for different protocol issue in ipv6 implementation in smack module(kernel ver 3.18)

[Vishal Goel]

 [PATCH] This patch fixes the issue when 2 servers uses same IP and
 port but different protocols(Udp and tcp). And they are using different
 SMACK64IPIN labels.Tcp server is using "test" and udp server is using
 "test-in". Now when we try to run tcp client with SMACK64IPOUT label as
 "test", then connection denied error comes. It should not happen since both
 tcp server and client labels are same. This happens because there is no check
 for protocol in smk_ipv6_port_label() function.It checks whether there is an
 existing port entry on the basis of port only.So it updates the previous port
 entry in the list. Due to which smack label gets changed for previous entry
 in the "smk_ipv6_port_list" list and permission denied error comes. Now a
 check has been added for socket type also.Now if 2 processes uses same port
 but different protocols (tcp or udp), then 2 different port entries will be
 added in the list. Similarly which checking smack access in
 smk_ipv6_port_check() function,  port entry is searched on the basis of both
 port and protocol.

Signed-off-by: Vishal Goel <vishal.goel@xxxxxxxxxxx>
            Himanshu Shukla <himanshu.sh@xxxxxxxxxxx>
---
 security/smack/smack.h     | 1 +
 security/smack/smack_lsm.c | 5 +++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/security/smack/smack.h b/security/smack/smack.h
index b828a37..e8c6477 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -135,6 +135,7 @@ struct smk_port_label {
      unsigned short          smk_port;   /* the port number */
      struct smack_known      *smk_in;    /* inbound label */
      struct smack_known      *smk_out;   /* outgoing label */
+     short                   sock_type;      /*Socket type*/
 };

 /*
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index b3427ee..81647e8 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -2264,7 +2264,7 @@ static void smk_ipv6_port_label(struct socket
*sock, struct sockaddr *address)
       */
      rcu_read_lock();
      list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
-           if (spp->smk_port != port)
+           if (spp->smk_port != port || spp->sock_type != sock->type)
                  continue;
            spp->smk_port = port;
            spp->smk_sock = sk;
@@ -2285,6 +2285,7 @@ static void smk_ipv6_port_label(struct socket
*sock, struct sockaddr *address)
      spp->smk_sock = sk;
      spp->smk_in = ssp->smk_in;
      spp->smk_out = ssp->smk_out;
+     spp->sock_type = sock->type;

      mutex_lock(&smack_ipv6_lock);
      list_add_rcu(&spp->list, &smk_ipv6_port_list);
@@ -2345,7 +2346,7 @@ static int smk_ipv6_port_check(struct sock *sk,
struct sockaddr_in6 *address,
      }
      rcu_read_lock();
      list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
-           if (spp->smk_port != port)
+           if (spp->smk_port != port || spp->sock_type != sk->sk_type)
                  continue;
            object = spp->smk_in;
            if (act == SMK_CONNECTING)
--
1.8.3.2
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