netlink: avoid a double skb free in genlmsg_mcast()

commit 02a2385f37a7c6594c9d89b64c4a1451276f08eb upstream.

nlmsg_multicast() consumes always the skb, thus the original skb must be
freed only when this function is called with a clone.

Fixes: cb9f7a9a5c96 ("netlink: ensure to loop over all netns in genlmsg_multicast_allns()")
Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 3b1b2a2..c41301a 100644 (file)
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -942,7 +942,7 @@ static int genlmsg_mcast(struct sk_buff *skb, u32 pid, unsigned long group,
        if (!err)
                delivered = true;
        else if (err != -ESRCH)
-               goto error;
+               return err;
        return delivered ? 0 : -ESRCH;
  error:
        kfree_skb(skb);