As discussed in [1], there is a problem with get_random_bytes being
used before the RNG has actually been seeded. The solution for fixing
this appears to be multi-pronged. One of those prongs involves adding
a simple blocking API so that modules that use the RNG in process
context can just sleep (in an interruptable manner) until the RNG is
ready to be used. This winds up being a very useful API that covers
a few use cases, several of which are included in this patch set.
[1] http://www.openwall.com/lists/kernel-hardening/2017/06/02/2
Changes v3->v4:
- Mark one patch for stable
- Operation ordering on batched entropy invalidation
- Separate out big_key into its own patch to the keys mailing list
- General cleanups
Jason A. Donenfeld (13):
random: invalidate batched entropy after crng init
random: add synchronous API for the urandom pool
random: add get_random_{bytes,u32,u64,int,long,once}_wait family
security/keys: ensure RNG is seeded before use
crypto/rng: ensure that the RNG is ready before using
iscsi: ensure RNG is seeded before use
ceph: ensure RNG is seeded before using
cifs: use get_random_u32 for 32-bit lock random
rhashtable: use get_random_u32 for hash_rnd
net/neighbor: use get_random_u32 for 32-bit hash random
net/route: use get_random_int for random counter
bluetooth/smp: ensure RNG is properly seeded before ECDH use
random: warn when kernel uses unseeded randomness
crypto/rng.c | 6 +-
drivers/char/random.c | 93 +++
drivers/target/iscsi/iscsi_target_auth.c | 14 -
drivers/target/iscsi/iscsi_target_login.c | 22 +---
fs/cifs/cifsfs.c | 2 +-
include/linux/net.h | 2 +
include/linux/once.h | 2 +
include/linux/random.h| 26 +
lib/Kconfig.debug | 16 ++
lib/rhashtable.c | 2 +-
net/bluetooth/hci_request.c | 6 ++
net/bluetooth/smp.c | 18 --
net/ceph/ceph_common.c| 6 +-
net/core/neighbour.c | 3 +-
net/ipv4/route.c | 3 +-
security/keys/encrypted-keys/encrypted.c | 8 ++-
security/keys/key.c | 16 +++---
17 files changed, 198 insertions(+), 47 deletions(-)
--
2.13.0
