diff mbox

[2/2] crypto/drbg: account for no longer returning -EALREADY

Message ID 20171019204506.25090-2-Jason@zx2c4.com (mailing list archive)
State Not Applicable
Delegated to: Herbert Xu
Headers show

Commit Message

Jason A. Donenfeld Oct. 19, 2017, 8:45 p.m. UTC
We now structure things in a way that assumes the seeding function is
always eventually called.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 crypto/drbg.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

Comments

Stephan Mueller Oct. 21, 2017, 7:22 p.m. UTC | #1
Am Donnerstag, 19. Oktober 2017, 22:45:06 CEST schrieb Jason A. Donenfeld:

Hi Jason,

> We now structure things in a way that assumes the seeding function is
> always eventually called.
> 
> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> ---
>  crypto/drbg.c | 20 +++++---------------
>  1 file changed, 5 insertions(+), 15 deletions(-)
> 
> diff --git a/crypto/drbg.c b/crypto/drbg.c
> index 70018397e59a..501e013cb96c 100644
> --- a/crypto/drbg.c
> +++ b/crypto/drbg.c
> @@ -1411,18 +1411,8 @@ static int drbg_prepare_hrng(struct drbg_state *drbg)
> 
>  	err = add_random_ready_callback(&drbg->random_ready);
> 
> -	switch (err) {
> -	case 0:
> -		break;
> -
> -	case -EALREADY:
> -		err = 0;
> -		/* fall through */
> -
> -	default:
> -		drbg->random_ready.func = NULL;
> +	if (err)
>  		return err;

Don't you change the logic flow here? In case the add_random_ready_callback 
returns 0 because the ready function is already called due to crng_ready(), 
the new code above in the patch set continues. But with the current code, it 
will return at this point and do not perform the allocation below.



Ciao
Stephan
diff mbox

Patch

diff --git a/crypto/drbg.c b/crypto/drbg.c
index 70018397e59a..501e013cb96c 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -1411,18 +1411,8 @@  static int drbg_prepare_hrng(struct drbg_state *drbg)
 
 	err = add_random_ready_callback(&drbg->random_ready);
 
-	switch (err) {
-	case 0:
-		break;
-
-	case -EALREADY:
-		err = 0;
-		/* fall through */
-
-	default:
-		drbg->random_ready.func = NULL;
+	if (err)
 		return err;
-	}
 
 	drbg->jent = crypto_alloc_rng("jitterentropy_rng", 0, 0);
 
@@ -1432,7 +1422,7 @@  static int drbg_prepare_hrng(struct drbg_state *drbg)
 	 */
 	drbg->reseed_threshold = 50;
 
-	return err;
+	return 0;
 }
 
 /*
@@ -1526,9 +1516,9 @@  static int drbg_instantiate(struct drbg_state *drbg, struct drbg_string *pers,
  */
 static int drbg_uninstantiate(struct drbg_state *drbg)
 {
-	if (drbg->random_ready.func) {
-		del_random_ready_callback(&drbg->random_ready);
-		cancel_work_sync(&drbg->seed_work);
+	del_random_ready_callback(&drbg->random_ready);
+	cancel_work_sync(&drbg->seed_work);
+	if (drbg->jent) {
 		crypto_free_rng(drbg->jent);
 		drbg->jent = NULL;
 	}