[PATCH v2 5/6] crypto: DRBG - make drbg_prepare_hrng() handle jent instantiation errors

From: Nicolai Stange
Date: Mon Nov 15 2021 - 09:20:06 EST


Now that drbg_prepare_hrng() doesn't do anything but to instantiate a
jitterentropy crypto_rng instance, it looks a little odd to have the
related error handling at its only caller, drbg_instantiate().

Move the handling of jitterentropy allocation failures from
drbg_instantiate() close to the allocation itself in drbg_prepare_hrng().

There is no change in behaviour.

Signed-off-by: Nicolai Stange <nstange@xxxxxxx>
Reviewed-by: Stephan Müller <smueller@xxxxxxxxxx>
---
crypto/drbg.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/crypto/drbg.c b/crypto/drbg.c
index 2b03a05a9e99..9f6485962ecc 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1516,6 +1516,14 @@ static int drbg_prepare_hrng(struct drbg_state *drbg)
return 0;

drbg->jent = crypto_alloc_rng("jitterentropy_rng", 0, 0);
+ if (IS_ERR(drbg->jent)) {
+ const int err = PTR_ERR(drbg->jent);
+
+ drbg->jent = NULL;
+ if (fips_enabled || err != -ENOENT)
+ return err;
+ pr_info("DRBG: Continuing without Jitter RNG\n");
+ }

return 0;
}
@@ -1571,14 +1579,6 @@ static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers,
if (ret)
goto free_everything;

- if (IS_ERR(drbg->jent)) {
- ret = PTR_ERR(drbg->jent);
- drbg->jent = NULL;
- if (fips_enabled || ret != -ENOENT)
- goto free_everything;
- pr_info("DRBG: Continuing without Jitter RNG\n");
- }
-
reseed = false;
}

--
2.26.2