On Fri, May 06, 2022 at 09:23:22AM +0100, Giovanni Cabiddu wrote:
> Set to zero the DH context buffers containing the DH key before they are
> freed.
That says what, but not why.
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: c9839143ebbf ("crypto: qat - Add DH support")
> Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@xxxxxxxxx>
> Reviewed-by: Adam Guerin <adam.guerin@xxxxxxxxx>
> Reviewed-by: Wojciech Ziemba <wojciech.ziemba@xxxxxxxxx>
> ---
> drivers/crypto/qat/qat_common/qat_asym_algs.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/crypto/qat/qat_common/qat_asym_algs.c b/drivers/crypto/qat/qat_common/qat_asym_algs.c
> index d75eb77c9fb9..2fec89b8a188 100644
> --- a/drivers/crypto/qat/qat_common/qat_asym_algs.c
> +++ b/drivers/crypto/qat/qat_common/qat_asym_algs.c
> @@ -421,14 +421,17 @@ static int qat_dh_set_params(struct qat_dh_ctx *ctx, struct dh *params)
> static void qat_dh_clear_ctx(struct device *dev, struct qat_dh_ctx *ctx)
> {
> if (ctx->g) {
> + memzero_explicit(ctx->g, ctx->p_size);
> dma_free_coherent(dev, ctx->p_size, ctx->g, ctx->dma_g);
Why is a memset() not sufficient here?
And what is this solving? Who would get this stale data?
thanks,
greg k-h
