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Date:   Wed, 22 May 2019 10:49:56 +0200
From:   Pavel Machek <pavel@denx.de>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Gilad Ben-Yossef <gilad@benyossef.com>,
        Herbert Xu <herbert@gondor.apana.org.au>
Subject: Re: [PATCH 4.19 046/105] crypto: ccree - dont map MAC key on stack
Message-ID: <20190522084956.GA8174@amd>
References: <20190520115247.060821231@linuxfoundation.org>
 <20190520115250.198221588@linuxfoundation.org>
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Hi!

> The MAC hash key might be passed to us on stack. Copy it to
> a slab buffer before mapping to gurantee proper DMA mapping.
>=20
> Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
> Cc: stable@vger.kernel.org # v4.19+
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>=20
> ---
>  drivers/crypto/ccree/cc_hash.c |   24 +++++++++++++++++++++---
>  1 file changed, 21 insertions(+), 3 deletions(-)
>=20
> --- a/drivers/crypto/ccree/cc_hash.c
> +++ b/drivers/crypto/ccree/cc_hash.c
> @@ -64,6 +64,7 @@ struct cc_hash_alg {
>  struct hash_key_req_ctx {
>  	u32 keylen;
>  	dma_addr_t key_dma_addr;
> +	u8 *key;
>  };
> =20
>  /* hash per-session context */

AFAICT, key is used just as a local variable in cc_hash_setkey() and
cc_xcbc_setkey() functions. Could we make it local variable to save a
bit of memory (and make code less confusing)?

Thanks,
								Pavel

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(english) http://www.livejournal.com/~pavelmachek
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