netfilter: fix hardcoded size assumptions

get_random_bytes() is sometimes called with a hard coded size assumption
of an integer. This could not be true for next centuries. This patch
replace it with a compile time statement.

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>

3 files changed, 6 insertions, 4 deletions

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index f3aa4e65b15..2235432c59d 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -472,7 +472,8 @@ struct nf_conn *nf_conntrack_alloc(struct net *net,
         struct nf_conn *ct;
 
         if (unlikely(!nf_conntrack_hash_rnd_initted)) {
-                get_random_bytes(&nf_conntrack_hash_rnd, 4);
+                get_random_bytes(&nf_conntrack_hash_rnd,
+                                sizeof(nf_conntrack_hash_rnd));
                 nf_conntrack_hash_rnd_initted = 1;
         }
 
@@ -1103,7 +1104,7 @@ int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
 
         /* We have to rehahs for the new table anyway, so we also can
          * use a newrandom seed */
-        get_random_bytes(&rnd, 4);
+        get_random_bytes(&rnd, sizeof(rnd));
 
         /* Lookups in the old hash might happen in parallel, which means we
          * might get false negatives during connection lookup. New connections
diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 3a8a34a6d37..357ba39d4c8 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -72,7 +72,8 @@ static unsigned int nf_ct_expect_dst_hash(const struct nf_conntrack_tuple *tuple
         unsigned int hash;
 
         if (unlikely(!nf_ct_expect_hash_rnd_initted)) {
-                get_random_bytes(&nf_ct_expect_hash_rnd, 4);
+                get_random_bytes(&nf_ct_expect_hash_rnd,
+                                 sizeof(nf_ct_expect_hash_rnd));
                 nf_ct_expect_hash_rnd_initted = 1;
         }
 
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
index f97fded024c..2482055e1c5 100644
--- a/net/netfilter/xt_hashlimit.c
+++ b/net/netfilter/xt_hashlimit.c
@@ -149,7 +149,7 @@ dsthash_alloc_init(struct xt_hashlimit_htable *ht,
         /* initialize hash with random val at the time we allocate
          * the first hashtable entry */
         if (!ht->rnd_initialized) {
-                get_random_bytes(&ht->rnd, 4);
+                get_random_bytes(&ht->rnd, sizeof(ht->rnd));
                 ht->rnd_initialized = 1;
         }