TCP sockets for IPv4 and IPv6 that are not listeners or in closed
stated are allowed to be attached to a KCM mux.
Fixes: ab7ac4eb9832 ("kcm: Kernel Connection Multiplexor module")
Reported-by: [email protected]
Signed-off-by: Tom Herbert <[email protected]>
---
net/kcm/kcmsock.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c
index d4e98f20fc2a..474ea2200592 100644
--- a/net/kcm/kcmsock.c
+++ b/net/kcm/kcmsock.c
@@ -1391,6 +1391,15 @@ static int kcm_attach(struct socket *sock, struct socket
*csock,
if (csk->sk_family == PF_KCM)
return -EOPNOTSUPP;
+ /* Only allow TCP sockets to be attached for now */
+ if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) ||
+ csk->sk_protocol != IPPROTO_TCP)
+ return -EOPNOTSUPP;
+
+ /* Don't allow listeners or closed sockets */
+ if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE)
+ return -EOPNOTSUPP;
+
psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL);
if (!psock)
return -ENOMEM;
--
2.11.0
