crypto: qat - set to zero DH parameters before free

Set to zero the context buffers containing the DH key before they are
freed.
This is a defense in depth measure that avoids keys to be recovered from
memory in case the system is compromised between the free of the buffer
and when that area of memory (containing keys) gets overwritten.

Cc: stable@vger.kernel.org
Fixes: c9839143eb ("crypto: qat - Add DH support")
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Adam Guerin <adam.guerin@intel.com>
Reviewed-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Giovanni Cabiddu 2022-05-09 14:19:27 +01:00 committed by Herbert Xu
parent 349d03ffd5
commit 1731160ff7
1 changed files with 3 additions and 0 deletions

View File

@ -420,14 +420,17 @@ 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;
}