[PATCH net 1/4] net/ipv4: Put target net when address dump fails due to bad attributes

[David Ahern]

From: David Ahern <dsah...@gmail.com>

If tgt_net is set based on IFA_TARGET_NETNSID attribute in the dump
request, make sure all error paths call put_net.

Fixes: 5fcd266a9f64 ("net/ipv4: Add support for dumping addresses for a 
specific device")
Fixes: c33078e3dfb1 ("net/ipv4: Update inet_dump_ifaddr for strict data 
checking")
Reported-by: Li RongQing <lirongq...@baidu.com>
Signed-off-by: David Ahern <dsah...@gmail.com>
---
 net/ipv4/devinet.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 63d5b58fbfdb..9250b309c742 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1761,7 +1761,7 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct 
netlink_callback *cb)
        struct net_device *dev;
        struct in_device *in_dev;
        struct hlist_head *head;
-       int err;
+       int err = 0;
 
        s_h = cb->args[0];
        s_idx = idx = cb->args[1];
@@ -1771,12 +1771,15 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct 
netlink_callback *cb)
                err = inet_valid_dump_ifaddr_req(nlh, &fillargs, &tgt_net,
                                                 skb->sk, cb);
                if (err < 0)
-                       return err;
+                       goto put_tgt_net;
 
+               err = 0;
                if (fillargs.ifindex) {
                        dev = __dev_get_by_index(tgt_net, fillargs.ifindex);
-                       if (!dev)
-                               return -ENODEV;
+                       if (!dev) {
+                               err = -ENODEV;
+                               goto put_tgt_net;
+                       }
 
                        in_dev = __in_dev_get_rtnl(dev);
                        if (in_dev) {
@@ -1821,7 +1824,7 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct 
netlink_callback *cb)
        if (fillargs.netnsid >= 0)
                put_net(tgt_net);
 
-       return skb->len;
+       return err < 0 ? err : skb->len;
 }
 
 static void rtmsg_ifa(int event, struct in_ifaddr *ifa, struct nlmsghdr *nlh,
-- 
2.11.0