staging: comedi: fix infoleak to userspace

[ upstream commit 819cbb120eaec7e014e5abd029260db1ca8c5735 ]

driver_name and board_name are pointers to strings, not buffers of size
COMEDI_NAMELEN.  Copying COMEDI_NAMELEN bytes of a string containing
less than COMEDI_NAMELEN-1 bytes would leak some unrelated bytes.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index aeb2c00875cd2110117afae796edb95748134e39..9b5df0ea0f7dee3590b59f825fb0f262c00a6fd9 100644 (file)
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -383,8 +383,8 @@ static int do_devinfo_ioctl(struct comedi_device *dev,
        /* fill devinfo structure */
        devinfo.version_code = COMEDI_VERSION_CODE;
        devinfo.n_subdevs = dev->n_subdevices;
-       memcpy(devinfo.driver_name, dev->driver->driver_name, COMEDI_NAMELEN);
-       memcpy(devinfo.board_name, dev->board_name, COMEDI_NAMELEN);
+       strlcpy(devinfo.driver_name, dev->driver->driver_name, COMEDI_NAMELEN);
+       strlcpy(devinfo.board_name, dev->board_name, COMEDI_NAMELEN);
 
        if (read_subdev)
                devinfo.read_subdevice = read_subdev - dev->subdevices;