Re: [PATCH 4.19 046/105] crypto: ccree - dont map MAC key on stack

[Pavel Machek]

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.
> 
> Signed-off-by: Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx # v4.19+
> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> 
> ---
>  drivers/crypto/ccree/cc_hash.c |   24 +++++++++++++++++++++---
>  1 file changed, 21 insertions(+), 3 deletions(-)
> 
> --- 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;
>  };
>  
>  /* 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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