Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random

Pull random updates from Ted Ts'o:
 "Add wait_for_random_bytes() and get_random_*_wait() functions so that
  callers can more safely get random bytes if they can block until the
  CRNG is initialized.

  Also print a warning if get_random_*() is called before the CRNG is
  initialized. By default, only one single-line warning will be printed
  per boot. If CONFIG_WARN_ALL_UNSEEDED_RANDOM is defined, then a
  warning will be printed for each function which tries to get random
  bytes before the CRNG is initialized. This can get spammy for certain
  architecture types, so it is not enabled by default"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: reorder READ_ONCE() in get_random_uXX
  random: suppress spammy warnings about unseeded randomness
  random: warn when kernel uses unseeded randomness
  net/route: use get_random_int for random counter
  net/neighbor: use get_random_u32 for 32-bit hash random
  rhashtable: use get_random_u32 for hash_rnd
  ceph: ensure RNG is seeded before using
  iscsi: ensure RNG is seeded before use
  cifs: use get_random_u32 for 32-bit lock random
  random: add get_random_{bytes,u32,u64,int,long,once}_wait family
  random: add wait_for_random_bytes() API

3 files changed, 7 insertions, 5 deletions

diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c
index 3d265c5..5c036d2 100644
--- a/net/ceph/ceph_common.c
+++ b/net/ceph/ceph_common.c
@@ -599,7 +599,11 @@ struct ceph_client *ceph_create_client(struct ceph_options *opt, void *private)
 {
 	struct ceph_client *client;
 	struct ceph_entity_addr *myaddr = NULL;
-	int err = -ENOMEM;
+	int err;
+
+	err = wait_for_random_bytes();
+	if (err < 0)
+		return ERR_PTR(err);
 
 	client = kzalloc(sizeof(*client), GFP_KERNEL);
 	if (client == NULL)
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index e31fc11..d071362 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -347,8 +347,7 @@ out_entries:
 
 static void neigh_get_hash_rnd(u32 *x)
 {
-	get_random_bytes(x, sizeof(*x));
-	*x |= 1;
+	*x = get_random_u32() | 1;
 }
 
 static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index c816cd5..0383e66f 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2979,8 +2979,7 @@ static __net_init int rt_genid_init(struct net *net)
 {
 	atomic_set(&net->ipv4.rt_genid, 0);
 	atomic_set(&net->fnhe_genid, 0);
-	get_random_bytes(&net->ipv4.dev_addr_genid,
-			 sizeof(net->ipv4.dev_addr_genid));
+	atomic_set(&net->ipv4.dev_addr_genid, get_random_int());
 	return 0;
 }