4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx>
[ 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@xxxxxxxxx>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;