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Date: Sun, 24 Dec 2023 20:55:57 +0100
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To: virtualization@lists.linux.dev, linux-crypto@vger.kernel.org,
 kernel-janitors@vger.kernel.org, "David S. Miller" <davem@davemloft.net>,
 Gonglei <arei.gonglei@huawei.com>, Herbert Xu <herbert@gondor.apana.org.au>,
 Jason Wang <jasowang@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>,
 Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Content-Language: en-GB
From: Markus Elfring <Markus.Elfring@web.de>
Subject: [PATCH] crypto: virtio - Less function calls in
 __virtio_crypto_akcipher_do_req() after error detection
Cc: LKML <linux-kernel@vger.kernel.org>, cocci@inria.fr
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From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 24 Dec 2023 20:42:19 +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@users.sourceforge.net>
=2D--
 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..15dbe67f0d31 100644
=2D-- 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 vi=
rtio_crypto_akcipher_request
 	struct virtio_crypto *vcrypto =3D ctx->vcrypto;
 	struct virtio_crypto_op_data_req *req_data =3D vc_req->req_data;
 	struct scatterlist *sgs[4], outhdr_sg, inhdr_sg, srcdata_sg, dstdata_sg;
-	void *src_buf =3D NULL, *dst_buf =3D NULL;
+	void *src_buf, *dst_buf =3D NULL;
 	unsigned int num_out =3D 0, num_in =3D 0;
 	int node =3D dev_to_node(&vcrypto->vdev->dev);
 	unsigned long flags;
-	int ret =3D -ENOMEM;
+	int ret;
 	bool verify =3D vc_akcipher_req->opcode =3D=3D VIRTIO_CRYPTO_AKCIPHER_VE=
RIFY;
 	unsigned int src_len =3D verify ? req->src_len + req->dst_len : req->src=
_len;

@@ -239,7 +239,7 @@ static int __virtio_crypto_akcipher_do_req(struct virt=
io_crypto_akcipher_request
 	/* src data */
 	src_buf =3D 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 virt=
io_crypto_akcipher_request
 		/* dst data */
 		dst_buf =3D 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++] =3D &dstdata_sg;
@@ -277,9 +277,9 @@ static int __virtio_crypto_akcipher_do_req(struct virt=
io_crypto_akcipher_request
 	return 0;

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

=2D-
2.43.0