From 6d2650831d1b16fce3140d9ce6216149afce4e36 Mon Sep 17 00:00:00 2001 From: Subash Abhinov Kasiviswanathan Date: Tue, 9 Aug 2016 21:09:44 -0600 Subject: [PATCH] Revert "genetlink: disallow subscribing to unknown mcast groups" Commit 5ad6300524c0332 ("genetlink: disallow subscribing to unknown mcast groups") disallows userspace to subscribe to groups that don't exist in kernel. As a result, communication between processes is not possible unless they explicitly register a dummy group with the kernel even if the communication is between userspace processes only. NETLINK_USERSOCK cannot be used here since userspace processes would require CAP_NET_ADMIN to receive multicast messages which is available for priveleged processes only. Fix this problem by reverting the change till a solution is determined internally and upstream discussion. CRs-Fixed: 1052589 Change-Id: Id559d9ef9d1e0a25e3bbdc81503978f01c6ed85f Signed-off-by: Subash Abhinov Kasiviswanathan --- net/netlink/genetlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index bc0e504f33a6..80649934cf3b 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -993,7 +993,7 @@ static struct genl_multicast_group genl_ctrl_groups[] = { static int genl_bind(struct net *net, int group) { - int i, err = -ENOENT; + int i, err = 0; down_read(&cb_lock); for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {