From c2176f0098d994050c88d34d37c551d033f2f18f Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Sun, 16 Jul 2017 19:22:06 +0200 Subject: [PATCH] crypto: rng - ensure that the RNG is ready before using Otherwise, we might be seeding the RNG using bad randomness, which is dangerous. The one use of this function from within the kernel -- not from userspace -- is being removed (keys/big_key), so that call site isn't relevant in assessing this. Cc: Herbert Xu Signed-off-by: Jason A. Donenfeld Signed-off-by: Herbert Xu --- crypto/rng.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/crypto/rng.c b/crypto/rng.c index 5e8469244960..b4a618668161 100644 --- a/crypto/rng.c +++ b/crypto/rng.c @@ -43,12 +43,14 @@ int crypto_rng_reset(struct crypto_rng *tfm, const u8 *seed, unsigned int slen) if (!buf) return -ENOMEM; - get_random_bytes(buf, slen); + err = get_random_bytes_wait(buf, slen); + if (err) + goto out; seed = buf; } err = crypto_rng_alg(tfm)->seed(tfm, seed, slen); - +out: kzfree(buf); return err; } -- 2.30.2