Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
IronPort-SDR: +jqdWu9hzF+UozJIx3GeMjVwAHzx3jTzexjcBkX++A6/ErV7ESuE3s6bUgZ4OKAvahe3bhUZ33
 0EfV3PhOVeoQ==
IronPort-SDR: pTsqcZHQQ3nPDSGFdQBjwFz9HTWkoVOffURZxPc2szniHsomaYCFLjyRjSjMQ/bejoqNdNeOwO
 3f582BsuQ/jw==
Date:   Thu, 23 Jul 2020 04:32:35 +0300
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     David Howells <dhowells@redhat.com>
Cc:     torvalds@linux-foundation.org,
        Wei Yongjun <weiyongjun1@huawei.com>, keyrings@vger.kernel.org,
        linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] keys: asymmetric: fix error return code in
 software_key_query()
Message-ID: <20200723013223.GA45081@linux.intel.com>
References: <159485211858.2340757.9890754969922775496.stgit@warthog.procyon.org.uk>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <159485211858.2340757.9890754969922775496.stgit@warthog.procyon.org.uk>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Jul 15, 2020 at 11:28:38PM +0100, David Howells wrote:
> From: Wei Yongjun <weiyongjun1@huawei.com>
> 
> Fix to return negative error code -ENOMEM from kmalloc() error handling
> case instead of 0, as done elsewhere in this function.
> 
> Fixes: f1774cb8956a ("X.509: parse public key parameters from x509 for akcipher")
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> Signed-off-by: David Howells <dhowells@redhat.com>

Why f1774cb8956a lacked any possible testing? It extends ABI anyway.

I think it is a kind of change that would require more screening before
getting applied.

> ---
> 
>  crypto/asymmetric_keys/public_key.c |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
> index d7f43d4ea925..e5fae4e838c0 100644
> --- a/crypto/asymmetric_keys/public_key.c
> +++ b/crypto/asymmetric_keys/public_key.c
> @@ -119,6 +119,7 @@ static int software_key_query(const struct kernel_pkey_params *params,
>  	if (IS_ERR(tfm))
>  		return PTR_ERR(tfm);
>  
> +	ret = -ENOMEM;

This is extremely confusing to read way to handle 'ret'.

Would be way more cleaner to be just simple and stupid:

	if (!key) {
		ret = -ENOMEM;
		goto error_free_tfm;
	}

>  	key = kmalloc(pkey->keylen + sizeof(u32) * 2 + pkey->paramlen,
>  		      GFP_KERNEL);
>  	if (!key)

/Jarkko