On 12/4/2024 10:30 PM, Mickaël Salaün wrote:
On Thu, Oct 17, 2024 at 07:04:47PM +0800, Mikhail Ivanov wrote:
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).
sk_is_tcp() is used for this to check address family of the socket
before doing INET-specific address length validation. This is required
for error consistency.
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@xxxxxxxxxxxxxxxxxxx>
---
Changes since v1:
* Validate socket family (=INET{,6}) before any other checks
with sk_is_tcp().
---
security/landlock/net.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/security/landlock/net.c b/security/landlock/net.c
index fdc1bb0a9c5d..1e80782ba239 100644
--- a/security/landlock/net.c
+++ b/security/landlock/net.c
@@ -66,8 +66,8 @@ static int current_check_access_socket(struct socket *const sock,
if (WARN_ON_ONCE(dom->num_layers < 1))
return -EACCES;
- /* Checks if it's a (potential) TCP socket. */
- if (sock->type != SOCK_STREAM)
+ /* Do not restrict non-TCP sockets. */
You can remove this comment because the following check is explicit.
ok, thx
+ if (!sk_is_tcp(sock->sk))
return 0;
/* Checks for minimal header length to safely read sa_family. */
--
2.34.1
