[XFRM]: Fix possible overflow of sock->sk_policy

Spotted by, and original patch by, Balazs Scheidler.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index ecade4893a13..8da3e25b2c4c 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1350,6 +1350,9 @@ static struct xfrm_policy *xfrm_compile_policy(u16 family, int opt,
         if (nr > XFRM_MAX_DEPTH)
                 return NULL;
 
+        if (p->dir > XFRM_POLICY_OUT)
+                return NULL;
+
         xp = xfrm_policy_alloc(GFP_KERNEL);
         if (xp == NULL) {
                 *dir = -ENOBUFS;