[PATCH v3 07/10] crypto: qat - add param check for RSA

[Giovanni Cabiddu <giovanni.cabiddu@intel.com>]

Reject requests with a source buffer that is bigger than the size of the
key. This is to prevent a possible integer underflow that might happen
when copying the source scatterlist into a linear buffer.

Cc: stable@vger.kernel.org
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>
---
 drivers/crypto/qat/qat_common/qat_asym_algs.c | 8 ++++++++
 1 file changed, 8 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..1021202b2fbd 100644
--- a/drivers/crypto/qat/qat_common/qat_asym_algs.c
+++ b/drivers/crypto/qat/qat_common/qat_asym_algs.c
@@ -653,6 +653,10 @@ static int qat_rsa_enc(struct akcipher_request *req)
 		req->dst_len = ctx->key_sz;
 		return -EOVERFLOW;
 	}
+
+	if (req->src_len > ctx->key_sz)
+		return -EINVAL;
+
 	memset(msg, '\0', sizeof(*msg));
 	ICP_QAT_FW_PKE_HDR_VALID_FLAG_SET(msg->pke_hdr,
 					  ICP_QAT_FW_COMN_REQ_FLAG_SET);
@@ -782,6 +786,10 @@ static int qat_rsa_dec(struct akcipher_request *req)
 		req->dst_len = ctx->key_sz;
 		return -EOVERFLOW;
 	}
+
+	if (req->src_len > ctx->key_sz)
+		return -EINVAL;
+
 	memset(msg, '\0', sizeof(*msg));
 	ICP_QAT_FW_PKE_HDR_VALID_FLAG_SET(msg->pke_hdr,
 					  ICP_QAT_FW_COMN_REQ_FLAG_SET);
-- 
2.35.1