linux-kernel - [PATCH v2] crypto: virtio - Less function calls in __virtio_crypto_akcipher_do

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Message-ID: <7bf9a4fa-1675-45a6-88dd-82549ae2c6e0@web.de>
Date: Tue, 26 Dec 2023 11:12:23 +0100
From: Markus Elfring <Markus.Elfring@....de>
To: kernel test robot <lkp@...el.com>, virtualization@...ts.linux.dev,
 linux-crypto@...r.kernel.org, kernel-janitors@...r.kernel.org,
 "David S. Miller" <davem@...emloft.net>, Gonglei <arei.gonglei@...wei.com>,
 Herbert Xu <herbert@...dor.apana.org.au>, Jason Wang <jasowang@...hat.com>,
 "Michael S. Tsirkin" <mst@...hat.com>, Xuan Zhuo <xuanzhuo@...ux.alibaba.com>
Cc: llvm@...ts.linux.dev, oe-kbuild-all@...ts.linux.dev,
 netdev@...r.kernel.org, LKML <linux-kernel@...r.kernel.org>, cocci@...ia.fr
Subject: [PATCH v2] crypto: virtio - Less function calls in
 __virtio_crypto_akcipher_do_req() after error detection

From: Markus Elfring <elfring@...rs.sourceforge.net>
Date: Tue, 26 Dec 2023 11:00:20 +0100

The kfree() function was called in up to two cases by the
__virtio_crypto_akcipher_do_req() function during error handling
even if the passed variable contained a null pointer.
This issue was detected by using the Coccinelle software.

* Adjust jump targets.

* Delete two initialisations which became unnecessary
  with this refactoring.

Signed-off-by: Markus Elfring <elfring@...rs.sourceforge.net>
---

v2:
A typo was fixed for the delimiter of a label.

 drivers/crypto/virtio/virtio_crypto_akcipher_algs.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c b/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
index 2621ff8a9376..057da5bd8d30 100644
--- a/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
@@ -224,11 +224,11 @@ static int __virtio_crypto_akcipher_do_req(struct virtio_crypto_akcipher_request
 	struct virtio_crypto *vcrypto = ctx->vcrypto;
 	struct virtio_crypto_op_data_req *req_data = vc_req->req_data;
 	struct scatterlist *sgs[4], outhdr_sg, inhdr_sg, srcdata_sg, dstdata_sg;
-	void *src_buf = NULL, *dst_buf = NULL;
+	void *src_buf, *dst_buf = NULL;
 	unsigned int num_out = 0, num_in = 0;
 	int node = dev_to_node(&vcrypto->vdev->dev);
 	unsigned long flags;
-	int ret = -ENOMEM;
+	int ret;
 	bool verify = vc_akcipher_req->opcode == VIRTIO_CRYPTO_AKCIPHER_VERIFY;
 	unsigned int src_len = verify ? req->src_len + req->dst_len : req->src_len;

@@ -239,7 +239,7 @@ static int __virtio_crypto_akcipher_do_req(struct virtio_crypto_akcipher_request
 	/* src data */
 	src_buf = kcalloc_node(src_len, 1, GFP_KERNEL, node);
 	if (!src_buf)
-		goto err;
+		return -ENOMEM;

 	if (verify) {
 		/* for verify operation, both src and dst data work as OUT direction */
@@ -254,7 +254,7 @@ static int __virtio_crypto_akcipher_do_req(struct virtio_crypto_akcipher_request
 		/* dst data */
 		dst_buf = kcalloc_node(req->dst_len, 1, GFP_KERNEL, node);
 		if (!dst_buf)
-			goto err;
+			goto free_src;

 		sg_init_one(&dstdata_sg, dst_buf, req->dst_len);
 		sgs[num_out + num_in++] = &dstdata_sg;
@@ -277,9 +277,9 @@ static int __virtio_crypto_akcipher_do_req(struct virtio_crypto_akcipher_request
 	return 0;

 err:
-	kfree(src_buf);
 	kfree(dst_buf);
-
+free_src:
+	kfree(src_buf);
 	return -ENOMEM;
 }

--
2.43.0