[PATCH] crypto: sa2ul: Add error handling for DMA metadata retrieval

[Haotian Zhang <vulab@iscas.ac.cn>]

The SA2UL driver calls dmaengine_desc_get_metadata_ptr() in AES, SHA and
AEAD DMA paths without checking for error pointers. If the metadata
retrieval fails, these functions may dereference an ERR_PTR value,
leading to kernel crashes or undefined behavior.

Add proper IS_ERR() checks after each dmaengine_desc_get_metadata_ptr()
call, log the failure, clean up the DMA state, and complete the crypto
request with an error.

Fixes: 7694b6ca649f ("crypto: sa2ul - Add crypto driver")
Fixes: 2dc53d004745 ("crypto: sa2ul - add sha1/sha256/sha512 support")
Fixes: d2c8ac187fc9 ("crypto: sa2ul - Add AEAD algorithm support")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
---
 drivers/crypto/sa2ul.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/crypto/sa2ul.c b/drivers/crypto/sa2ul.c
index fdc0b2486069..eaec284b5e4b 100644
--- a/drivers/crypto/sa2ul.c
+++ b/drivers/crypto/sa2ul.c
@@ -1051,6 +1051,13 @@ static void sa_aes_dma_in_callback(void *data)
 	if (req->iv) {
 		mdptr = (__be32 *)dmaengine_desc_get_metadata_ptr(rxd->tx_in, &pl,
 							       &ml);
+		if (IS_ERR(mdptr)) {
+			dev_err(rxd->ddev, "Failed to get AES RX metadata pointer: %ld\n",
+				PTR_ERR(mdptr));
+			sa_free_sa_rx_data(rxd);
+			skcipher_request_complete(req, PTR_ERR(mdptr));
+			return;
+		}
 		result = (u32 *)req->iv;
 
 		for (i = 0; i < (rxd->enc_iv_size / 4); i++)
@@ -1272,6 +1279,12 @@ static int sa_run(struct sa_req *req)
 	 * crypto algorithm to be used, data sizes, different keys etc.
 	 */
 	mdptr = (u32 *)dmaengine_desc_get_metadata_ptr(tx_out, &pl, &ml);
+	if (IS_ERR(mdptr)) {
+		dev_err(pdata->dev, "Failed to get TX metadata pointer: %ld\n",
+			PTR_ERR(mdptr));
+		ret = PTR_ERR(mdptr);
+		goto err_cleanup;
+	}
 
 	sa_prepare_tx_desc(mdptr, (sa_ctx->cmdl_size + (SA_PSDATA_CTX_WORDS *
 				   sizeof(u32))), cmdl, sizeof(sa_ctx->epib),
@@ -1367,6 +1380,14 @@ static void sa_sha_dma_in_callback(void *data)
 	authsize = crypto_ahash_digestsize(tfm);
 
 	mdptr = (__be32 *)dmaengine_desc_get_metadata_ptr(rxd->tx_in, &pl, &ml);
+	if (IS_ERR(mdptr)) {
+		dev_err(rxd->ddev, "Failed to get SHA RX metadata pointer: %ld\n",
+			PTR_ERR(mdptr));
+		sa_free_sa_rx_data(rxd);
+		skcipher_request_complete(req, PTR_ERR(mdptr));
+		return;
+	}
+
 	result = (u32 *)req->result;
 
 	for (i = 0; i < (authsize / 4); i++)
@@ -1677,6 +1698,13 @@ static void sa_aead_dma_in_callback(void *data)
 	authsize = crypto_aead_authsize(tfm);
 
 	mdptr = (u32 *)dmaengine_desc_get_metadata_ptr(rxd->tx_in, &pl, &ml);
+	if (IS_ERR(mdptr)) {
+		dev_err(rxd->ddev, "Failed to get AEAD RX metadata pointer: %ld\n",
+			PTR_ERR(mdptr));
+		sa_free_sa_rx_data(rxd);
+		skcipher_request_complete(req, PTR_ERR(mdptr));
+		return;
+	}
 	for (i = 0; i < (authsize / 4); i++)
 		mdptr[i + 4] = swab32(mdptr[i + 4]);
 
-- 
2.50.1.windows.1