ipv6/addrlabel: fix ip6addrlbl_get()

commit e459dfeeb64008b2d23bdf600f03b3605dbb8152 upstream.

ip6addrlbl_get() has never worked. If ip6addrlbl_hold() succeeded,
ip6addrlbl_get() will exit with '-ESRCH'. If ip6addrlbl_hold() failed,
ip6addrlbl_get() will use about to be free ip6addrlbl_entry pointer.

Fix this by inverting ip6addrlbl_hold() check.

Fixes: 2a8cc6c89039 ("[IPV6] ADDRCONF: Support RFC3484 configurable address selection policy table.")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Cong Wang <cwang@twopensource.com>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit 39b214ba1a357359f9c0be6ef8d21f2e5187567a)
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
index 6ff73c4c126aeabc14e102df05d879f4463825e9..5b1403de63922e8f6b955f9dfc627bc823d04264 100644 (file)
--- a/net/ipv6/addrlabel.c
+++ b/net/ipv6/addrlabel.c
@@ -557,7 +557,7 @@ static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr* nlh,
 
        rcu_read_lock();
        p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);
-       if (p && ip6addrlbl_hold(p))
+       if (p && !ip6addrlbl_hold(p))
                p = NULL;
        lseq = ip6addrlbl_table.seq;
        rcu_read_unlock();