This is a note to let you know that I've just added the patch titled staging: comedi: disallow COMEDI_DEVCONFIG on non-board minors
to the 3.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: staging-comedi-disallow-comedi_devconfig-on-non-board-minors.patch and it can be found in the queue-3.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@vger.kernel.org> know about it. >From 754ab5c0e55dd118273ca2c217c4d95e9fbc8259 Mon Sep 17 00:00:00 2001 From: Ian Abbott <abbo...@mev.co.uk> Date: Mon, 28 Jan 2013 16:14:31 +0000 Subject: staging: comedi: disallow COMEDI_DEVCONFIG on non-board minors From: Ian Abbott <abbo...@mev.co.uk> commit 754ab5c0e55dd118273ca2c217c4d95e9fbc8259 upstream. Comedi has two sorts of minor devices: (a) normal board minor devices in the range 0 to COMEDI_NUM_BOARD_MINORS-1 inclusive; and (b) special subdevice minor devices in the range COMEDI_NUM_BOARD_MINORS upwards that are used to open the same underlying comedi device as the normal board minor devices, but with non-default read and write subdevices for asynchronous commands. The special subdevice minor devices get created when a board supporting asynchronous commands is attached to a normal board minor device, and destroyed when the board is detached from the normal board minor device. One way to attach or detach a board is by using the COMEDI_DEVCONFIG ioctl. This should only be used on normal board minors as the special subdevice minors are too ephemeral. In particular, the change introduced in commit 7d3135af399e92cf4c9bbc5f86b6c140aab3b88c ("staging: comedi: prevent auto-unconfig of manually configured devices") breaks horribly for special subdevice minor devices. Since there's no legitimate use for the COMEDI_DEVCONFIG ioctl on a special subdevice minor device node, disallow it and return -ENOTTY. Signed-off-by: Ian Abbott <abbo...@mev.co.uk> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- drivers/staging/comedi/comedi_fops.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -136,6 +136,11 @@ static long comedi_unlocked_ioctl(struct /* Device config is special, because it must work on * an unconfigured device. */ if (cmd == COMEDI_DEVCONFIG) { + if (minor >= COMEDI_NUM_BOARD_MINORS) { + /* Device config not appropriate on non-board minors. */ + rc = -ENOTTY; + goto done; + } rc = do_devconfig_ioctl(dev, (struct comedi_devconfig __user *)arg); if (rc == 0) Patches currently in stable-queue which might be from abbo...@mev.co.uk are queue-3.0/staging-comedi-disallow-comedi_devconfig-on-non-board-minors.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html