[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>

1 files changed, 6 insertions, 1 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 58dfa82..1dd20cf 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)