[XFRM]: xfrm_algo_clone() allocates too much memory

alg_key_len is the length in bits of the key, not in bytes.

Best way to fix this is to move alg_len() function from net/xfrm/xfrm_user.c 
to include/net/xfrm.h, and to use it in xfrm_algo_clone()

alg_len() is renamed to xfrm_alg_len() because of its global exposition.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 12 insertions, 12 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 58dfa82889aa..1dd20cf17982 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1188,10 +1188,15 @@ static inline int xfrm_aevent_is_on(void)
         return ret;
 }
 
+static inline int xfrm_alg_len(struct xfrm_algo *alg)
+{
+        return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
+}
+
 #ifdef CONFIG_XFRM_MIGRATE
 static inline struct xfrm_algo *xfrm_algo_clone(struct xfrm_algo *orig)
 {
-        return (struct xfrm_algo *)kmemdup(orig, sizeof(*orig) + orig->alg_key_len, GFP_KERNEL);
+        return kmemdup(orig, xfrm_alg_len(orig), GFP_KERNEL);
 }
 
 static inline void xfrm_states_put(struct xfrm_state **states, int n)
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index e75dbdcb08a4..c4f6419b1769 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -31,11 +31,6 @@
 #include <linux/in6.h>
 #endif
 
-static inline int alg_len(struct xfrm_algo *alg)
-{
-        return sizeof(*alg) + ((alg->alg_key_len + 7) / 8);
-}
-
 static int verify_one_alg(struct nlattr **attrs, enum xfrm_attr_type_t type)
 {
         struct nlattr *rt = attrs[type];
@@ -45,7 +40,7 @@ static int verify_one_alg(struct nlattr **attrs, enum xfrm_attr_type_t type)
                 return 0;
 
         algp = nla_data(rt);
-        if (nla_len(rt) < alg_len(algp))
+        if (nla_len(rt) < xfrm_alg_len(algp))
                 return -EINVAL;
 
         switch (type) {
@@ -204,7 +199,7 @@ static int attach_one_algo(struct xfrm_algo **algpp, u8 *props,
                 return -ENOSYS;
         *props = algo->desc.sadb_alg_id;
 
-        p = kmemdup(ualg, alg_len(ualg), GFP_KERNEL);
+        p = kmemdup(ualg, xfrm_alg_len(ualg), GFP_KERNEL);
         if (!p)
                 return -ENOMEM;
 
@@ -516,9 +511,9 @@ static int copy_to_user_state_extra(struct xfrm_state *x,
                 NLA_PUT_U64(skb, XFRMA_LASTUSED, x->lastused);
 
         if (x->aalg)
-                NLA_PUT(skb, XFRMA_ALG_AUTH, alg_len(x->aalg), x->aalg);
+                NLA_PUT(skb, XFRMA_ALG_AUTH, xfrm_alg_len(x->aalg), x->aalg);
         if (x->ealg)
-                NLA_PUT(skb, XFRMA_ALG_CRYPT, alg_len(x->ealg), x->ealg);
+                NLA_PUT(skb, XFRMA_ALG_CRYPT, xfrm_alg_len(x->ealg), x->ealg);
         if (x->calg)
                 NLA_PUT(skb, XFRMA_ALG_COMP, sizeof(*(x->calg)), x->calg);
 
@@ -1978,9 +1973,9 @@ static inline size_t xfrm_sa_len(struct xfrm_state *x)
 {
         size_t l = 0;
         if (x->aalg)
-                l += nla_total_size(alg_len(x->aalg));
+                l += nla_total_size(xfrm_alg_len(x->aalg));
         if (x->ealg)
-                l += nla_total_size(alg_len(x->ealg));
+                l += nla_total_size(xfrm_alg_len(x->ealg));
         if (x->calg)
                 l += nla_total_size(sizeof(*x->calg));
         if (x->encap)