Merge tag 'v3.13' into stable-3.14

Linux 3.13

Conflicts:
	security/selinux/hooks.c

Trivial merge issue in selinux_inet_conn_request() likely due to me
including patches that I sent to the stable folks in my next tree
resulting in the patch hitting twice (I think).  Thankfully it was an
easy fix this time, but regardless, lesson learned, I will not do that
again.

1 files changed, 17 insertions, 12 deletions

diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index ab7bd35bb312..f195d9316e55 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -8,12 +8,26 @@
 #include <net/inetpeer.h>
 #include <net/tcp.h>
 
-int sysctl_tcp_fastopen __read_mostly;
+int sysctl_tcp_fastopen __read_mostly = TFO_CLIENT_ENABLE;
 
 struct tcp_fastopen_context __rcu *tcp_fastopen_ctx;
 
 static DEFINE_SPINLOCK(tcp_fastopen_ctx_lock);
 
+void tcp_fastopen_init_key_once(bool publish)
+{
+	static u8 key[TCP_FASTOPEN_KEY_LENGTH];
+
+	/* tcp_fastopen_reset_cipher publishes the new context
+	 * atomically, so we allow this race happening here.
+	 *
+	 * All call sites of tcp_fastopen_cookie_gen also check
+	 * for a valid cookie, so this is an acceptable risk.
+	 */
+	if (net_get_random_once(key, sizeof(key)) && publish)
+		tcp_fastopen_reset_cipher(key, sizeof(key));
+}
+
 static void tcp_fastopen_ctx_free(struct rcu_head *head)
 {
 	struct tcp_fastopen_context *ctx =
@@ -70,6 +84,8 @@ void tcp_fastopen_cookie_gen(__be32 src, __be32 dst,
 	__be32 path[4] = { src, dst, 0, 0 };
 	struct tcp_fastopen_context *ctx;
 
+	tcp_fastopen_init_key_once(true);
+
 	rcu_read_lock();
 	ctx = rcu_dereference(tcp_fastopen_ctx);
 	if (ctx) {
@@ -78,14 +94,3 @@ void tcp_fastopen_cookie_gen(__be32 src, __be32 dst,
 	}
 	rcu_read_unlock();
 }
-
-static int __init tcp_fastopen_init(void)
-{
-	__u8 key[TCP_FASTOPEN_KEY_LENGTH];
-
-	get_random_bytes(key, sizeof(key));
-	tcp_fastopen_reset_cipher(key, sizeof(key));
-	return 0;
-}
-
-late_initcall(tcp_fastopen_init);