[PATCH 2.6.32 39/42] ipv6/addrlabel: fix ip6addrlbl_get()

From: Willy Tarreau
Date: Sat Jan 23 2016 - 09:58:57 EST

2.6.32-longterm review patch. If anyone has any objections, please let me know.


From: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxx>
Reviewed-by: Cong Wang <cwang@xxxxxxxxxxxxxxxx>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
(cherry picked from commit 39b214ba1a357359f9c0be6ef8d21f2e5187567a)
Signed-off-by: Willy Tarreau <w@xxxxxx>
net/ipv6/addrlabel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
index 6ff73c4..5b1403d 100644
--- 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,

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;