Re: [kernel-hardening] [PATCH v4 07/13] ceph: ensure RNG is seeded before using

[Theodore Ts'o]

On Tue, Jun 06, 2017 at 07:47:58PM +0200, Jason A. Donenfeld wrote:
> 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 

Thanks, applied to the dev branch.

- Ted

[PATCH v4 07/13] ceph: ensure RNG is seeded before using

[Jason A. Donenfeld]

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 
---
 net/ceph/ceph_common.c | 6 +-
 1 file changed, 5 insertions(+), 1 deletion(-)

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)
-- 
2.13.0