On Fri, May 06, 2022 at 03:38:59PM +0100, Giovanni Cabiddu wrote:
> Set to zero the DH context buffers containing the DH key before they are
> freed.
> This is to make sure keys are not leaked out by a subsequent memory
> allocation.
>
> 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..25bbd22085c3 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) {
> + memset(ctx->g, 0, ctx->p_size);
> dma_free_coherent(dev, ctx->p_size, ctx->g, ctx->dma_g);
> ctx->g = NULL;
> }
> if (ctx->xa) {
> + memset(ctx->xa, 0, ctx->p_size);
> dma_free_coherent(dev, ctx->p_size, ctx->xa, ctx->dma_xa);
> ctx->xa = NULL;
> }
> if (ctx->p) {
> + memset(ctx->p, 0, ctx->p_size);
> dma_free_coherent(dev, ctx->p_size, ctx->p, ctx->dma_p);
> ctx->p = NULL;
> }
> --
> 2.35.1
>
As I just wrote, I do not think you need this. If you do, please
explain what you are trying to protect the kernel from here. Itself?
thanks,
greg k-h
