From ab38ffccdf4e0b86b8e6be1ff8c7ce53df74c4ec Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Tue, 6 Feb 2018 14:48:32 +0100 Subject: [PATCH 1/1] netlink: ensure to loop over all netns in genlmsg_multicast_allns() commit cb9f7a9a5c96a773bbc9c70660dc600cfff82f82 upstream. Nowadays, nlmsg_multicast() returns only 0 or -ESRCH but this was not the case when commit 134e63756d5f was pushed. However, there was no reason to stop the loop if a netns does not have listeners. Returns -ESRCH only if there was no listeners in all netns. To avoid having the same problem in the future, I didn't take the assumption that nlmsg_multicast() returns only 0 or -ESRCH. Fixes: 134e63756d5f ("genetlink: make netns aware") CC: Johannes Berg Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller [bwh: Backported to 3.2: s/portid/pid/] Signed-off-by: Ben Hutchings --- net/netlink/genetlink.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 874f8ffbe423..3b1b2a29e3a3 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -917,6 +917,7 @@ static int genlmsg_mcast(struct sk_buff *skb, u32 pid, unsigned long group, { struct sk_buff *tmp; struct net *net, *prev = NULL; + bool delivered = false; int err; for_each_net_rcu(net) { @@ -928,14 +929,21 @@ static int genlmsg_mcast(struct sk_buff *skb, u32 pid, unsigned long group, } err = nlmsg_multicast(prev->genl_sock, tmp, pid, group, flags); - if (err) + if (!err) + delivered = true; + else if (err != -ESRCH) goto error; } prev = net; } - return nlmsg_multicast(prev->genl_sock, skb, pid, group, flags); + err = nlmsg_multicast(prev->genl_sock, skb, pid, group, flags); + if (!err) + delivered = true; + else if (err != -ESRCH) + goto error; + return delivered ? 0 : -ESRCH; error: kfree_skb(skb); return err; -- 2.30.2