From: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Mon, 19 May 2025 20:57:55 +0000 (-0700)
Subject: tcp: Restrict SO_TXREHASH to TCP socket.
X-Git-Tag: v6.16-rc1~132^2~45^2~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ae4f2f59e1f9c7c9cab1641a3c9645e587f0bc72;p=thirdparty%2Fkernel%2Flinux.git

tcp: Restrict SO_TXREHASH to TCP socket.

sk->sk_txrehash is only used for TCP.

Let's restrict SO_TXREHASH to TCP to reflect this.

Later, we will make sk_txrehash a part of the union for other
protocol families.

Note that we need to modify BPF selftest not to get/set
SO_TEREHASH for non-TCP sockets.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/sock.c b/net/core/sock.c
index 347ce75482f56..d7d6d3a8efe58 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1276,6 +1276,8 @@ int sk_setsockopt(struct sock *sk, int level, int optname,
 		return 0;
 		}
 	case SO_TXREHASH:
+		if (!sk_is_tcp(sk))
+			return -EOPNOTSUPP;
 		if (val < -1 || val > 1)
 			return -EINVAL;
 		if ((u8)val == SOCK_TXREHASH_DEFAULT)
@@ -2102,6 +2104,9 @@ int sk_getsockopt(struct sock *sk, int level, int optname,
 		break;
 
 	case SO_TXREHASH:
+		if (!sk_is_tcp(sk))
+			return -EOPNOTSUPP;
+
 		/* Paired with WRITE_ONCE() in sk_setsockopt() */
 		v.val = READ_ONCE(sk->sk_txrehash);
 		break;
diff --git a/tools/testing/selftests/bpf/progs/setget_sockopt.c b/tools/testing/selftests/bpf/progs/setget_sockopt.c
index 0107a24b7522b..d330b15119794 100644
--- a/tools/testing/selftests/bpf/progs/setget_sockopt.c
+++ b/tools/testing/selftests/bpf/progs/setget_sockopt.c
@@ -83,6 +83,14 @@ struct loop_ctx {
 	struct sock *sk;
 };
 
+static bool sk_is_tcp(struct sock *sk)
+{
+	return (sk->__sk_common.skc_family == AF_INET ||
+		sk->__sk_common.skc_family == AF_INET6) &&
+		sk->sk_type == SOCK_STREAM &&
+		sk->sk_protocol == IPPROTO_TCP;
+}
+
 static int bpf_test_sockopt_flip(void *ctx, struct sock *sk,
 				 const struct sockopt_test *t,
 				 int level)
@@ -91,6 +99,9 @@ static int bpf_test_sockopt_flip(void *ctx, struct sock *sk,
 
 	opt = t->opt;
 
+	if (opt == SO_TXREHASH && !sk_is_tcp(sk))
+		return 0;
+
 	if (bpf_getsockopt(ctx, level, opt, &old, sizeof(old)))
 		return 1;
 	/* kernel initialized txrehash to 255 */