4.9-stable review patch. If anyone has any objections, please let me know.
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From: Nicolas Dichtel nicolas.dichtel@6wind.com
[ Upstream commit cb9f7a9a5c96a773bbc9c70660dc600cfff82f82 ]
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 johannes.berg@intel.com Signed-off-by: Nicolas Dichtel nicolas.dichtel@6wind.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netlink/genetlink.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
--- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -1103,6 +1103,7 @@ static int genlmsg_mcast(struct sk_buff { struct sk_buff *tmp; struct net *net, *prev = NULL; + bool delivered = false; int err;
for_each_net_rcu(net) { @@ -1114,14 +1115,21 @@ static int genlmsg_mcast(struct sk_buff } err = nlmsg_multicast(prev->genl_sock, tmp, portid, group, flags); - if (err) + if (!err) + delivered = true; + else if (err != -ESRCH) goto error; }
prev = net; }
- return nlmsg_multicast(prev->genl_sock, skb, portid, group, flags); + err = nlmsg_multicast(prev->genl_sock, skb, portid, group, flags); + if (!err) + delivered = true; + else if (err != -ESRCH) + goto error; + return delivered ? 0 : -ESRCH; error: kfree_skb(skb); return err;