[PATCH] net/ipv6: Fix a test against 'ipv6_find_idev()' return value

[Christophe JAILLET]

'ipv6_find_idev()' returns NULL on error, not an error pointer.
Update the test accordingly and return -ENOBUFS, as already done in
'addrconf_add_dev()', if NULL is returned.

Fixes: ("ipv6: allow userspace to add IFA_F_OPTIMISTIC addresses")
Signed-off-by: Christophe JAILLET <christophe.jail...@wanadoo.fr>
---
 net/ipv6/addrconf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 521e471f1cf9..8eeec6eb2bd3 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -4736,8 +4736,8 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr 
*nlh,
                         IFA_F_MCAUTOJOIN | IFA_F_OPTIMISTIC;
 
        idev = ipv6_find_idev(dev);
-       if (IS_ERR(idev))
-               return PTR_ERR(idev);
+       if (!idev)
+               return -ENOBUFS;
 
        if (!ipv6_allow_optimistic_dad(net, idev))
                cfg.ifa_flags &= ~IFA_F_OPTIMISTIC;
-- 
2.19.1