[34-longterm 121/179] staging: comedi: fix infoleak to userspace

From: Paul Gortmaker
Date: Mon May 14 2012 - 22:42:52 EST


From: Vasiliy Kulikov <segoon@xxxxxxxxxxxx>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git
If you see a problem with using this for longterm, please comment.
-------------------

commit 819cbb120eaec7e014e5abd029260db1ca8c5735 upstream.

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@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
drivers/staging/comedi/comedi_fops.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index aca9674..ac6527c 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -362,8 +362,8 @@ 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;
--
1.7.9.6

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