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
