Re: [PATCH] Btrfs: NUL-terminate path buffer in DEV_INFO ioctl result

[Josef Bacik <josef@redhat.com>]

On Thu, Apr 26, 2012 at 06:36:56PM +0200, Jim Meyering wrote:
> 
> A device with name of length BTRFS_DEVICE_PATH_NAME_MAX or longer
> would not be NUL-terminated in the DEV_INFO ioctl result buffer.
> 
> Signed-off-by: Jim Meyering <meyering@redhat.com>
> ---
>  fs/btrfs/ioctl.c |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 18cc23d..1578676 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -2258,16 +2258,17 @@ static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
>  		goto out;
>  	}
> 
>  	di_args->devid = dev->devid;
>  	di_args->bytes_used = dev->bytes_used;
>  	di_args->total_bytes = dev->total_bytes;
>  	memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
>  	strncpy(di_args->path, dev->name, sizeof(di_args->path));
> +	di_args->path[sizeof(di_args->path) - 1] = 0;
> 
>  out:
>  	if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
>  		ret = -EFAULT;
> 
>  	kfree(di_args);
>  	return ret;
>  }
> --
> 1.7.10.336.gc5e31

This didn't merge quite right onto btrfs-next btw so I've fixed it up manually
(but left the log/author/signed off intact).  Thanks,

Josef