From: Dmitry Safonov <dima@arista.com>
Date: Wed, 23 Nov 2022 17:38:58 +0000 (+0000)
Subject: net/tcp: Do cleanup on tcp_md5_key_copy() failure
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b389d1affc2cc2dc8686cdab303a30b2ad3a81d4;p=linux.git

net/tcp: Do cleanup on tcp_md5_key_copy() failure

If the kernel was short on (atomic) memory and failed to allocate it -
don't proceed to creation of request socket. Otherwise the socket would
be unsigned and userspace likely doesn't expect that the TCP is not
MD5-signed anymore.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 5d83a332f1ddc..7fae586405cfb 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1619,13 +1619,8 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 	addr = (union tcp_md5_addr *)&newinet->inet_daddr;
 	key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET);
 	if (key) {
-		/*
-		 * We're using one, so create a matching key
-		 * on the newsk structure. If we fail to get
-		 * memory, then we end up not copying the key
-		 * across. Shucks.
-		 */
-		tcp_md5_key_copy(newsk, addr, AF_INET, 32, l3index, key);
+		if (tcp_md5_key_copy(newsk, addr, AF_INET, 32, l3index, key))
+			goto put_and_exit;
 		sk_gso_disable(newsk);
 	}
 #endif
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 80df917ced5f2..11b736a76bd7e 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1364,13 +1364,14 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
 	/* Copy over the MD5 key from the original socket */
 	key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
 	if (key) {
-		/* We're using one, so create a matching key
-		 * on the newsk structure. If we fail to get
-		 * memory, then we end up not copying the key
-		 * across. Shucks.
-		 */
-		tcp_md5_key_copy(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
-				 AF_INET6, 128, l3index, key);
+		const union tcp_md5_addr *addr;
+
+		addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
+		if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
+			inet_csk_prepare_forced_close(newsk);
+			tcp_done(newsk);
+			goto out;
+		}
 	}
 #endif