[IPSEC]: Verify key payload in verify_one_algo

We need to verify that the payload contains enough data so that
attach_one_algo can copy alg_key_len bits from the payload.

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

1 files changed, 8 insertions, 1 deletions

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 15ba08602aa1..97509011c274 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -34,14 +34,21 @@ static int verify_one_alg(struct rtattr **xfrma, enum xfrm_attr_type_t type)
 {
         struct rtattr *rt = xfrma[type - 1];
         struct xfrm_algo *algp;
+        int len;
 
         if (!rt)
                 return 0;
 
-        if ((rt->rta_len - sizeof(*rt)) < sizeof(*algp))
+        len = (rt->rta_len - sizeof(*rt)) - sizeof(*algp);
+        if (len < 0)
                 return -EINVAL;
 
         algp = RTA_DATA(rt);
+
+        len -= (algp->alg_key_len + 7U) / 8; 
+        if (len < 0)
+                return -EINVAL;
+
         switch (type) {
         case XFRMA_ALG_AUTH:
                 if (!algp->alg_key_len &&