Merging upstream version 6.9.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 9 insertions, 1 deletions

diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index b4674f03d7..90b7f253d3 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -816,9 +816,17 @@ struct tls_context *tls_ctx_create(struct sock *sk)
 		return NULL;
 
 	mutex_init(&ctx->tx_lock);
-	rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
 	ctx->sk_proto = READ_ONCE(sk->sk_prot);
 	ctx->sk = sk;
+	/* Release semantic of rcu_assign_pointer() ensures that
+	 * ctx->sk_proto is visible before changing sk->sk_prot in
+	 * update_sk_prot(), and prevents reading uninitialized value in
+	 * tls_{getsockopt, setsockopt}. Note that we do not need a
+	 * read barrier in tls_{getsockopt,setsockopt} as there is an
+	 * address dependency between sk->sk_proto->{getsockopt,setsockopt}
+	 * and ctx->sk_proto.
+	 */
+	rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
 	return ctx;
 }