[PATCH v2 23/30] crypto: sa2ul - propagate DMA transfer errors

[Manorit Chawdhry]

DMA completion callbacks discard the transfer result and process output
metadata even when a transfer fails. This can report failed cipher or
hash requests as successful, or an AEAD transfer failure as a bad tag.

Use result-aware callbacks and return -EIO for failed or incomplete
transfers. Skip IV, digest and tag processing on error while preserving
DMA cleanup and completing each request once.

Signed-off-by: Manorit Chawdhry <m-chawdhry@xxxxxx>
---
 drivers/crypto/sa2ul.c | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/crypto/sa2ul.c b/drivers/crypto/sa2ul.c
index b33fac66c93f..18a69c890ee2 100644
--- a/drivers/crypto/sa2ul.c
+++ b/drivers/crypto/sa2ul.c
@@ -199,7 +199,7 @@ struct sa_rx_data {
  * @enc: true if this is an encode request
  * @src: source data
  * @dst: destination data
- * @callback: DMA callback for the request
+ * @callback: DMA callback receiving the transfer result
  * @mdata_size: metadata size passed to DMA
  */
 struct sa_req {
@@ -216,7 +216,7 @@ struct sa_req {
 	bool enc;
 	struct scatterlist *src;
 	struct scatterlist *dst;
-	dma_async_tx_callback callback;
+	dma_async_tx_callback_result callback;
 	u16 mdata_size;
 };
 
@@ -951,19 +951,21 @@ static void sa_free_sa_rx_data(struct sa_rx_data *rxd)
 	kfree(rxd);
 }
 
-static void sa_aes_dma_in_callback(void *data)
+static void sa_aes_dma_in_callback(void *data,
+				   const struct dmaengine_result *dma_result)
 {
 	struct sa_rx_data *rxd = data;
 	struct skcipher_request *req;
 	u8 *result;
 	__be32 *mdptr;
 	size_t ml, pl;
+	int err = dma_result->result == DMA_TRANS_NOERROR && !dma_result->residue ? 0 : -EIO;
 	int i;
 
 	sa_sync_from_device(rxd);
 	req = container_of(rxd->req, struct skcipher_request, base);
 
-	if (req->iv) {
+	if (!err && req->iv) {
 		mdptr = (__be32 *)dmaengine_desc_get_metadata_ptr(rxd->tx_in, &pl,
 							       &ml);
 		result = req->iv;
@@ -975,7 +977,7 @@ static void sa_aes_dma_in_callback(void *data)
 
 	sa_free_sa_rx_data(rxd);
 
-	skcipher_request_complete(req, 0);
+	skcipher_request_complete(req, err);
 }
 
 static void
@@ -1179,7 +1181,7 @@ static int sa_run(struct sa_req *req)
 	rxd->enc = req->enc;
 	rxd->iv_idx = req->ctx->iv_idx;
 	rxd->enc_iv_size = cmdl_upd_info.enc_iv.size;
-	rxd->tx_in->callback = req->callback;
+	rxd->tx_in->callback_result = req->callback;
 	rxd->tx_in->callback_param = rxd;
 
 	tx_out = dmaengine_prep_slave_sg(pdata->dma_tx, src,
@@ -1274,7 +1276,8 @@ static int sa_decrypt(struct skcipher_request *req)
 	return sa_cipher_run(req, req->iv, 0);
 }
 
-static void sa_sha_dma_in_callback(void *data)
+static void sa_sha_dma_in_callback(void *data,
+				   const struct dmaengine_result *dma_result)
 {
 	struct sa_rx_data *rxd = data;
 	struct ahash_request *req;
@@ -1284,9 +1287,12 @@ static void sa_sha_dma_in_callback(void *data)
 	size_t ml, pl;
 	u32 *result;
 	__be32 *mdptr;
+	int err = dma_result->result == DMA_TRANS_NOERROR && !dma_result->residue ? 0 : -EIO;
 
 	sa_sync_from_device(rxd);
 	req = container_of(rxd->req, struct ahash_request, base);
+	if (err)
+		goto out;
 	tfm = crypto_ahash_reqtfm(req);
 	authsize = crypto_ahash_digestsize(tfm);
 
@@ -1296,9 +1302,10 @@ static void sa_sha_dma_in_callback(void *data)
 	for (i = 0; i < (authsize / 4); i++)
 		result[i] = be32_to_cpu(mdptr[i + 4]);
 
+out:
 	sa_free_sa_rx_data(rxd);
 
-	ahash_request_complete(req, 0);
+	ahash_request_complete(req, err);
 }
 
 static int zero_message_process(struct ahash_request *req)
@@ -1584,7 +1591,8 @@ static void sa_sha_cra_exit(struct crypto_tfm *tfm)
 		sa_free_ctx_info(&ctx->enc, data);
 }
 
-static void sa_aead_dma_in_callback(void *data)
+static void sa_aead_dma_in_callback(void *data,
+				    const struct dmaengine_result *dma_result)
 {
 	struct sa_rx_data *rxd = data;
 	struct aead_request *req;
@@ -1594,11 +1602,13 @@ static void sa_aead_dma_in_callback(void *data)
 	u8 auth_tag[SA_MAX_AUTH_TAG_SZ];
 	size_t pl, ml;
 	int i;
-	int err = 0;
+	int err = dma_result->result == DMA_TRANS_NOERROR && !dma_result->residue ? 0 : -EIO;
 	u32 *mdptr;
 
 	sa_sync_from_device(rxd);
 	req = container_of(rxd->req, struct aead_request, base);
+	if (err)
+		goto out;
 	tfm = crypto_aead_reqtfm(req);
 	start = req->assoclen + req->cryptlen;
 	authsize = crypto_aead_authsize(tfm);
@@ -1618,6 +1628,7 @@ static void sa_aead_dma_in_callback(void *data)
 		err = crypto_memneq(&mdptr[4], auth_tag, authsize) ? -EBADMSG : 0;
 	}
 
+out:
 	sa_free_sa_rx_data(rxd);
 
 	aead_request_complete(req, err);

-- 
2.43.0