[PATCH] crypto: caam: Clear some memory in instantiate_rng()

[PATCH] crypto: caam: Clear some memory in instantiate_rng()

[Christophe JAILLET]

According to the comment at the end of the 'for' loop just a few lines
below, it looks needed to clear 'desc'.

So it should also be cleared for the first iteration.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
This patch is speculative, but can't hurt.

Maybe the memset() at the end of the 'for' loop could be removed instead.
---
 drivers/crypto/caam/ctrl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index 32253a064d0f..e4e971dc0f96 100644
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -276,7 +276,7 @@ static int instantiate_rng(struct device *ctrldev, int state_handle_mask,
 	int ret = 0, sh_idx;
 
 	ctrl = (struct caam_ctrl __iomem *)ctrlpriv->ctrl;
-	desc = kmalloc(CAAM_CMD_SZ * 7, GFP_KERNEL | GFP_DMA);
+	desc = kzalloc(CAAM_CMD_SZ * 7, GFP_KERNEL | GFP_DMA);
 	if (!desc)
 		return -ENOMEM;
 
-- 
2.32.0

Re: [PATCH] crypto: caam: Clear some memory in instantiate_rng()

[Herbert Xu]

On Tue, Mar 21, 2023 at 12:45:43AM +0100, Christophe JAILLET wrote:
> According to the comment at the end of the 'for' loop just a few lines
> below, it looks needed to clear 'desc'.
> 
> So it should also be cleared for the first iteration.
> 
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> This patch is speculative, but can't hurt.
> 
> Maybe the memset() at the end of the 'for' loop could be removed instead.

I think the memset can be removed.  Horia?
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

RE: [EXT] Re: [PATCH] crypto: caam: Clear some memory in instantiate_rng()

[Gaurav Jain]

Hi Herbert

> -----Original Message-----
> From: Herbert Xu <herbert@gondor.apana.org.au>
> Sent: Tuesday, March 21, 2023 8:57 AM
> To: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> Cc: Horia Geanta <horia.geanta@nxp.com>; Pankaj Gupta
> <pankaj.gupta@nxp.com>; Gaurav Jain <gaurav.jain@nxp.com>;
> davem@davemloft.net; linux-crypto@vger.kernel.org; linux-
> kernel@vger.kernel.org; kernel-janitors@vger.kernel.org
> Subject: [EXT] Re: [PATCH] crypto: caam: Clear some memory in
> instantiate_rng()
> 
> Caution: EXT Email
> 
> On Tue, Mar 21, 2023 at 12:45:43AM +0100, Christophe JAILLET wrote:
> > According to the comment at the end of the 'for' loop just a few lines
> > below, it looks needed to clear 'desc'.
> >
> > So it should also be cleared for the first iteration.
> >
> > Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> > ---
> > This patch is speculative, but can't hurt.
> >
> > Maybe the memset() at the end of the 'for' loop could be removed instead.
> 
> I think the memset can be removed.  Horia?
memset() is needed to clear the desc for each state handle before recreating descriptor.
So it is required.

Regards
Gaurav Jain
> --
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Re: [EXT] Re: [PATCH] crypto: caam: Clear some memory in instantiate_rng()

[Herbert Xu]

On Tue, Mar 21, 2023 at 05:03:24AM +0000, Gaurav Jain wrote:
>
> memset() is needed to clear the desc for each state handle before recreating descriptor.
> So it is required.

OK so we should move it to the top of the loop then.

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

RE: [EXT] Re: [PATCH] crypto: caam: Clear some memory in instantiate_rng()

[Gaurav Jain]

Hi

> -----Original Message-----
> From: Herbert Xu <herbert@gondor.apana.org.au>
> Sent: Tuesday, March 21, 2023 10:37 AM
> To: Gaurav Jain <gaurav.jain@nxp.com>
> Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>; Horia Geanta
> <horia.geanta@nxp.com>; Pankaj Gupta <pankaj.gupta@nxp.com>;
> davem@davemloft.net; linux-crypto@vger.kernel.org; linux-
> kernel@vger.kernel.org; kernel-janitors@vger.kernel.org
> Subject: Re: [EXT] Re: [PATCH] crypto: caam: Clear some memory in
> instantiate_rng()
> 
> Caution: EXT Email
> 
> On Tue, Mar 21, 2023 at 05:03:24AM +0000, Gaurav Jain wrote:
> >
> > memset() is needed to clear the desc for each state handle before
> recreating descriptor.
> > So it is required.
> 
> OK so we should move it to the top of the loop then.
kzalloc() will zeroize the contents of desc for the first time.
In this case memset() is ok at the end for instantiating other rng handles.
 
Thanks
Gaurav

> 
> Thanks,
> --
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