[PATCH net] net/ipv6: don't return positive numbers when nothing was dumped

[Jakub Kicinski]

in6_dump_addrs() returns a positive 1 if there was nothing to dump.
This return value can not be passed as return from inet6_dump_addr()
as is, because it will confuse rtnetlink, resulting in NLMSG_DONE
never getting set:

$ ip addr list dev lo
EOF on netlink
Dump terminated

Fixes: 7c1e8a3817c5 ("netlink: fixup regression in RTM_GETADDR")
Reported-by: Brendan Galloway <brendan.gallo...@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
---
 net/ipv6/addrconf.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 93d5ad2b1a69..87c98f7fe997 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -5120,6 +5120,9 @@ static int inet6_dump_addr(struct sk_buff *skb, struct 
netlink_callback *cb,
                        if (idev) {
                                err = in6_dump_addrs(idev, skb, cb, s_ip_idx,
                                                     &fillargs);
+                               if (err < 0)
+                                       goto put_tgt_net;
+                               err = 0;
                        }
                        goto put_tgt_net;
                }
-- 
2.19.2