[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>

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index ecade4893a139cc35d4fe345ce70242ede5358c4..8da3e25b2c4c1f305fd85428d3a9eb62b543bfba 100644 (file)
--- 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;