From ae5b806a3d3c23d9d3b57aecbe687a0bd82ab086 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 7 Jun 2017 22:44:54 -0400 Subject: ceph: ensure RNG is seeded before using Ceph uses the RNG for various nonce generations, and it shouldn't accept using bad randomness. So, we wait for the RNG to be properly seeded. We do this by calling wait_for_random_bytes() in a function that is certainly called in process context, early on, so that all subsequent calls to get_random_bytes are necessarily acceptable. Signed-off-by: Jason A. Donenfeld Cc: Ilya Dryomov Cc: "Yan, Zheng" Cc: Sage Weil Signed-off-by: Theodore Ts'o --- net/ceph/ceph_common.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/ceph/ceph_common.c b/net/ceph/ceph_common.c index 4fd02831beed..26ab58665f77 100644 --- a/net/ceph/ceph_common.c +++ b/net/ceph/ceph_common.c @@ -611,7 +611,11 @@ 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) -- cgit v1.2.3 From b3d0f7895d1251f0af0dd38410e7be3e52be4a1d Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 7 Jun 2017 23:00:05 -0400 Subject: net/neighbor: use get_random_u32 for 32-bit hash random Using get_random_u32 here is faster, more fitting of the use case, and just as cryptographically secure. It also has the benefit of providing better randomness at early boot, which is when many of these structures are assigned. Signed-off-by: Jason A. Donenfeld Cc: David Miller Signed-off-by: Theodore Ts'o --- net/core/neighbour.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'net') diff --git a/net/core/neighbour.c b/net/core/neighbour.c index d274f81fcc2c..9784133b0cdb 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -312,8 +312,7 @@ 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) -- cgit v1.2.3 From 7aed9f72c3c70bdc18e72ec086c1a0eafdcd273f Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 7 Jun 2017 23:01:20 -0400 Subject: net/route: use get_random_int for random counter Using get_random_int here is faster, more fitting of the use case, and just as cryptographically secure. It also has the benefit of providing better randomness at early boot, which is when many of these structures are assigned. Also, semantically, it's not really proper to have been assigning an atomic_t in this way before, even if in practice it works fine. Signed-off-by: Jason A. Donenfeld Cc: David Miller Signed-off-by: Theodore Ts'o --- net/ipv4/route.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'net') diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 655d9eebe43e..11e001a42094 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2936,8 +2936,7 @@ 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; } -- cgit v1.2.3