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;
To:     Zou Wei <zou_wei@huawei.com>
Cc:     <aacraid@microsemi.com>, <jejb@linux.ibm.com>,
        <martin.petersen@oracle.com>, <linux-scsi@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH -next] scsi: aacraid: Use memdup_user() as a cleanup
From:   "Martin K. Petersen" <martin.petersen@oracle.com>
Organization: Oracle Corporation
References: <1587524232-118733-1-git-send-email-zou_wei@huawei.com>
Date:   Fri, 24 Apr 2020 18:23:26 -0400
In-Reply-To: <1587524232-118733-1-git-send-email-zou_wei@huawei.com> (Zou
        Wei's message of "Wed, 22 Apr 2020 10:57:12 +0800")
Message-ID: <yq1wo64bk0x.fsf@oracle.com>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1.92 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


Zou,

> diff --git a/drivers/scsi/aacraid/commctrl.c b/drivers/scsi/aacraid/commctrl.c
> index ffe41bc..1ce1620 100644
> --- a/drivers/scsi/aacraid/commctrl.c
> +++ b/drivers/scsi/aacraid/commctrl.c
> @@ -513,17 +513,9 @@ static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
>  		goto cleanup;
>  	}
>  
> -	user_srbcmd = kmalloc(fibsize, GFP_KERNEL);
> -	if (!user_srbcmd) {
> -		dprintk((KERN_DEBUG"aacraid: Could not make a copy of the srb\n"));
> -		rcode = -ENOMEM;
> -		goto cleanup;
> -	}
> -	if(copy_from_user(user_srbcmd, user_srb,fibsize)){
> -		dprintk((KERN_DEBUG"aacraid: Could not copy srb from user\n"));
> -		rcode = -EFAULT;
> -		goto cleanup;
> -	}
> +	user_srbcmd = memdup_user(user_srb, fibsize);
> +	if (IS_ERR(user_srbcmd))
> +		return PTR_ERR(user_srbcmd);
>  
>  	flags = user_srbcmd->flags; /* from user in cpu order */
>  	switch (flags & (SRB_DataIn | SRB_DataOut)) {

This is not equivalent, is it? The original code does a goto cleanup;
whereas your patch returns on error.

-- 
Martin K. Petersen	Oracle Linux Engineering