audit: Send replies in the proper network namespace.

In perverse cases of file descriptor passing the current network
namespace of a process and the network namespace of a socket used by
that socket may differ.  Therefore use the network namespace of the
appropiate socket to ensure replies always go to the appropiate
socket.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

2 files changed, 15 insertions, 13 deletions

diff --git a/kernel/audit.c b/kernel/audit.c
index 71fb41f393d7..7b44bd47759c 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -570,9 +570,11 @@ static int audit_send_reply_thread(void *arg)
  * Allocates an skb, builds the netlink message, and sends it to the port id.
  * No failure notifications.
  */
-static void audit_send_reply(__u32 portid, int seq, int type, int done,
+static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
                              int multi, const void *payload, int size)
 {
+        u32 portid = NETLINK_CB(request_skb).portid;
+        struct net *net = sock_net(NETLINK_CB(request_skb).sk);
         struct sk_buff *skb;
         struct task_struct *tsk;
         struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
@@ -585,7 +587,7 @@ static void audit_send_reply(__u32 portid, int seq, int type, int done,
         if (!skb)
                 goto out;
 
-        reply->net = get_net(current->nsproxy->net_ns);
+        reply->net = get_net(net);
         reply->portid = portid;
         reply->skb = skb;
 
@@ -675,8 +677,7 @@ static int audit_get_feature(struct sk_buff *skb)
 
         seq = nlmsg_hdr(skb)->nlmsg_seq;
 
-        audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0,
-                         &af, sizeof(af));
+        audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &af, sizeof(af));
 
         return 0;
 }
@@ -796,8 +797,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 s.backlog               = skb_queue_len(&audit_skb_queue);
                 s.version               = AUDIT_VERSION_LATEST;
                 s.backlog_wait_time     = audit_backlog_wait_time;
-                audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0,
-                                 &s, sizeof(s));
+                audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
                 break;
         }
         case AUDIT_SET: {
@@ -907,7 +907,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                                            seq, data, nlmsg_len(nlh));
                 break;
         case AUDIT_LIST_RULES:
-                err = audit_list_rules_send(NETLINK_CB(skb).portid, seq);
+                err = audit_list_rules_send(skb, seq);
                 break;
         case AUDIT_TRIM:
                 audit_trim_trees();
@@ -972,8 +972,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                         memcpy(sig_data->ctx, ctx, len);
                         security_release_secctx(ctx, len);
                 }
-                audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO,
-                                0, 0, sig_data, sizeof(*sig_data) + len);
+                audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
+                                 sig_data, sizeof(*sig_data) + len);
                 kfree(sig_data);
                 break;
         case AUDIT_TTY_GET: {
@@ -985,8 +985,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 s.log_passwd = tsk->signal->audit_tty_log_passwd;
                 spin_unlock(&tsk->sighand->siglock);
 
-                audit_send_reply(NETLINK_CB(skb).portid, seq,
-                                 AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
+                audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
                 break;
         }
         case AUDIT_TTY_SET: {
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index a0d470131fd0..549bbb6e6597 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -32,6 +32,7 @@
 #include <linux/slab.h>
 #include <linux/security.h>
 #include <net/net_namespace.h>
+#include <net/sock.h>
 #include "audit.h"
 
 /*
@@ -1071,8 +1072,10 @@ int audit_rule_change(int type, __u32 portid, int seq, void *data,
  * @portid: target portid for netlink audit messages
  * @seq: netlink audit message sequence (serial) number
  */
-int audit_list_rules_send(__u32 portid, int seq)
+int audit_list_rules_send(struct sk_buff *request_skb, int seq)
 {
+        u32 portid = NETLINK_CB(request_skb).portid;
+        struct net *net = sock_net(NETLINK_CB(request_skb).sk);
         struct task_struct *tsk;
         struct audit_netlink_list *dest;
         int err = 0;
@@ -1086,7 +1089,7 @@ int audit_list_rules_send(__u32 portid, int seq)
         dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
         if (!dest)
                 return -ENOMEM;
-        dest->net = get_net(current->nsproxy->net_ns);
+        dest->net = get_net(net);
         dest->portid = portid;
         skb_queue_head_init(&dest->q);