Re: [PATCH] scsi: sd: add check for changing allow_restart

[weiping zhang <zhangweiping@didichuxing.com>]

On Thu, Sep 28, 2017 at 12:53:18AM +0800, weiping zhang wrote:
> /sys/class/scsi_disk/0:2:0:0/allow_restart can be changed to 0 unexpectly by
> writing invalid string, like following:
> 
> echo asdf > /sys/class/scsi_disk/0:2:0:0/allow_restart
> 
> Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
> ---
>  drivers/scsi/sd.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index 3ef2214..d18639f 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -253,6 +253,7 @@ static ssize_t
>  allow_restart_store(struct device *dev, struct device_attribute *attr,
>  		    const char *buf, size_t count)
>  {
> +	int err, v;
>  	struct scsi_disk *sdkp = to_scsi_disk(dev);
>  	struct scsi_device *sdp = sdkp->device;
>  
> @@ -262,7 +263,11 @@ allow_restart_store(struct device *dev, struct device_attribute *attr,
>  	if (sdp->type != TYPE_DISK && sdp->type != TYPE_ZBC)
>  		return -EINVAL;
>  
> -	sdp->allow_restart = simple_strtoul(buf, NULL, 10);
> +	err = kstrtoint(buf, 10, &v);
> +	if (err || (v != 0 && v != 1))
> +		return -EINVAL;
> +
> +	sdp->allow_restart = v;
>  
>  	return count;
>  }
> -- 
> 2.9.4
> 
Hello Martin,

Ping