[RFC PATCH v1 1/2] landlock: Fix non-TCP sockets restriction

[Mikhail Ivanov]

Do not check TCP access right if socket protocol is not IPPROTO_TCP.
LANDLOCK_ACCESS_NET_BIND_TCP and LANDLOCK_ACCESS_NET_CONNECT_TCP
should not restrict bind(2) and connect(2) for non-TCP protocols
(SCTP, MPTCP, SMC).

Closes: https://github.com/landlock-lsm/linux/issues/40
Fixes: fff69fb03dde ("landlock: Support network rules with TCP bind and connect")
Signed-off-by: Mikhail Ivanov <ivanov.mikhail1 at huawei-partners.com>
---
 security/landlock/net.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/landlock/net.c b/security/landlock/net.c
index bc3d943a7118..6f59dd98bb13 100644
--- a/security/landlock/net.c
+++ b/security/landlock/net.c
@@ -68,7 +68,7 @@ static int current_check_access_socket(struct socket *const sock,
 		return -EACCES;
 
 	/* Checks if it's a (potential) TCP socket. */
-	if (sock->type != SOCK_STREAM)
+	if (sock->type != SOCK_STREAM || sock->sk->sk_protocol != IPPROTO_TCP)
 		return 0;
 
 	/* Checks for minimal header length to safely read sa_family. */
-- 
2.34.1