udp:allow UDP cmsghdrs through io_uring

Signed-off-by: Victor Stewart <v@nametag.social>
0day-ci · Dec 16, 2020 · 6cce2a0155c3ee2a1550cb3d5e434cc85f055a60 · 6cce2a0
1 parent 3db1a3f
commit 6cce2a0155c3ee2a1550cb3d5e434cc85f055a60
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Showing 3 changed files with 7 additions and 3 deletions.
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
@@ -1052,6 +1052,7 @@ EXPORT_SYMBOL(inet_stream_ops);
 
 const struct proto_ops inet_dgram_ops = {
 	.family		   = PF_INET,
+	.flags		   = PROTO_CMSG_DATA_ONLY,
 	.owner		   = THIS_MODULE,
 	.release	   = inet_release,
 	.bind		   = inet_bind,

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
@@ -695,6 +695,7 @@ const struct proto_ops inet6_stream_ops = {
 
 const struct proto_ops inet6_dgram_ops = {
 	.family		   = PF_INET6,
+	.flags		   = PROTO_CMSG_DATA_ONLY,
 	.owner		   = THIS_MODULE,
 	.release	   = inet6_release,
 	.bind		   = inet6_bind,

diff --git a/net/socket.c b/net/socket.c
@@ -2399,9 +2399,11 @@ static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
 long __sys_sendmsg_sock(struct socket *sock, struct msghdr *msg,
 			unsigned int flags)
 {
-	/* disallow ancillary data requests from this path */
-	if (msg->msg_control || msg->msg_controllen)
-		return -EINVAL;
+	if (msg->msg_control || msg->msg_controllen) {
+		/* disallow ancillary data reqs unless cmsg is plain data */
+		if (!(sock->ops->flags & PROTO_CMSG_DATA_ONLY))
+			return -EINVAL;
+	}
 
 	return ____sys_sendmsg(sock, msg, flags, NULL, 0);
 }