[dm-devel] dm ioctl: prevent rename to empty name or uuid

Mikulas Patocka mpatocka at redhat.com
Thu Aug 29 17:48:57 UTC 2013


Acked-by: Mikulas Patocka <mpatocka at redhat.com>

On Thu, 29 Aug 2013, Alasdair G Kergon wrote:

> Try something like this?
> 
> From: Alasdair G Kergon <agk at redhat.com>
> 
> A device-mapper device must always have a name consisting of a non-empty
> string.  If the device also has a uuid, this similarly must not be an
> empty string.
> 
> The DM_DEV_CREATE_CMD ioctl enforces these rules when the device is
> created, but this patch is needed to enforce them when DM_DEV_RENAME_CMD
> is used to change the name or uuid.
> 
> Signed-off-by: Alasdair G Kergon <agk at redhat.com>
> Cc: Mike Snitzer <snitzer at redhat.com>                                                                                                                                                  
> Cc: Mikulas Patocka <mpatocka at redhat.com>   
> Reported-by: Zdenek Kabelac <zkabelac at redhat.com>    
> 
> ---
>  drivers/md/dm-ioctl.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: linux/drivers/md/dm-ioctl.c
> ===================================================================
> --- linux.orig/drivers/md/dm-ioctl.c
> +++ linux/drivers/md/dm-ioctl.c
> @@ -877,7 +877,7 @@ static int dev_rename(struct dm_ioctl *p
>  	unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
>  
>  	if (new_data < param->data ||
> -	    invalid_str(new_data, (void *) param + param_size) ||
> +	    invalid_str(new_data, (void *) param + param_size) || !*new_data ||
>  	    strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
>  		DMWARN("Invalid new mapped device name or uuid string supplied.");
>  		return -EINVAL;
> 




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