Re: [PATCH] crypto-virtio: fix memory-leak

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Aug 16, 2022 at 03:59:16PM +0800, Lei He wrote:
> From: lei he <helei.sig11@bytedance.com>
> 
> Fix memory-leak for virtio-crypto akcipher request, this problem is
> introduced by 59ca6c93387d3(virtio-crypto: implement RSA algorithm).
> The leak can be reproduced and tested with the following script
> inside virtual machine:
> 
> #!/bin/bash
> 
> LOOP_TIMES=10000
> 
> # required module: pkcs8_key_parser, virtio_crypto
> modprobe pkcs8_key_parser # if CONFIG_PKCS8_PRIVATE_KEY_PARSER=m
> modprobe virtio_crypto # if CONFIG_CRYPTO_DEV_VIRTIO=m
> rm -rf /tmp/data
> dd if=/dev/random of=/tmp/data count=1 bs=230
> 
> # generate private key and self-signed cert
> openssl req -nodes -x509 -newkey rsa:2048 -keyout key.pem \
> 		-outform der -out cert.der  \
> 		-subj "/C=CN/ST=GD/L=SZ/O=vihoo/OU=dev/CN=always.com/emailAddress=yy@always.com"
> # convert private key from pem to der
> openssl pkcs8 -in key.pem -topk8 -nocrypt -outform DER -out key.der
> 
> # add key
> PRIV_KEY_ID=`cat key.der | keyctl padd asymmetric test_priv_key @s`
> echo "priv key id = "$PRIV_KEY_ID
> PUB_KEY_ID=`cat cert.der | keyctl padd asymmetric test_pub_key @s`
> echo "pub key id = "$PUB_KEY_ID
> 
> # query key
> keyctl pkey_query $PRIV_KEY_ID 0
> keyctl pkey_query $PUB_KEY_ID 0
> 
> # here we only run pkey_encrypt becasuse it is the fastest interface
> function bench_pub() {
> 	keyctl pkey_encrypt $PUB_KEY_ID 0 /tmp/data enc=pkcs1 >/tmp/enc.pub
> }
> 
> # do bench_pub in loop to obtain the memory leak
> for (( i = 0; i < ${LOOP_TIMES}; ++i )); do
> 	bench_pub
> done
> 
> Signed-off-by: lei he <helei.sig11@bytedance.com>

trash below pls drop.


> # Please enter the commit message for your changes. Lines starting
> # with '#' will be kept; you may remove them yourself if you want to.
> # An empty message aborts the commit.
> #
> # Date:      Tue Aug 16 11:53:30 2022 +0800
> #
> # On branch master
> # Your branch is ahead of 'origin/master' by 1 commit.
> #   (use "git push" to publish your local commits)
> #
> # Changes to be committed:
> #	modified:   drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
> #
> # Untracked files:
> #	cert.der
> #	key.der
> #	key.pem
> #
> 
> # Please enter the commit message for your changes. Lines starting
> # with '#' will be kept; you may remove them yourself if you want to.
> # An empty message aborts the commit.
> #
> # Date:      Tue Aug 16 11:53:30 2022 +0800
> #
> # On branch master
> # Your branch is ahead of 'origin/master' by 1 commit.
> #   (use "git push" to publish your local commits)
> #
> # Changes to be committed:
> #	modified:   drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
> #
> # Untracked files:
> #	cert.der
> #	key.der
> #	key.pem
> #
> 
> # Please enter the commit message for your changes. Lines starting
> # with '#' will be kept; you may remove them yourself if you want to.
> # An empty message aborts the commit.
> #
> # Date:      Tue Aug 16 11:53:30 2022 +0800
> #
> # On branch master
> # Your branch is ahead of 'origin/master' by 1 commit.
> #   (use "git push" to publish your local commits)
> #
> # Changes to be committed:
> #	modified:   drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
> #
> # Untracked files:
> #	cert.der
> #	key.der
> #	key.pem
> #
> ---

with commit log fixed:

Acked-by: Michael S. Tsirkin <mst@redhat.com>

>  drivers/crypto/virtio/virtio_crypto_akcipher_algs.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c b/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
> index 2a60d0525cde..168195672e2e 100644
> --- a/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
> +++ b/drivers/crypto/virtio/virtio_crypto_akcipher_algs.c
> @@ -56,6 +56,10 @@ static void virtio_crypto_akcipher_finalize_req(
>  	struct virtio_crypto_akcipher_request *vc_akcipher_req,
>  	struct akcipher_request *req, int err)
>  {
> +	kfree(vc_akcipher_req->src_buf);
> +	kfree(vc_akcipher_req->dst_buf);
> +	vc_akcipher_req->src_buf = NULL;
> +	vc_akcipher_req->dst_buf = NULL;
>  	virtcrypto_clear_request(&vc_akcipher_req->base);
>  
>  	crypto_finalize_akcipher_request(vc_akcipher_req->base.dataq->engine, req, err);
> -- 
> 2.20.1

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