xfrm_user: verify policy direction at XFRM_MSG_POLEXPIRE handler

Add missing check for policy direction verification. This is
especially important since without this xfrm_user may end up
deleting per-socket policy which is not allowed.

Signed-off-by: Timo Teras <timo.teras@iki.fi>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 6106b72826d..da5ba86181d 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1741,6 +1741,10 @@ static int xfrm_add_pol_expire(struct sk_buff *skb, struct nlmsghdr *nlh,
         if (err)
                 return err;
 
+        err = verify_policy_dir(p->dir);
+        if (err)
+                return err;
+
         if (p->index)
                 xp = xfrm_policy_byid(net, mark, type, p->dir, p->index, 0, &err);
         else {