From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753414Ab1AEXHu (ORCPT ); Wed, 5 Jan 2011 18:07:50 -0500 Received: from kroah.org ([198.145.64.141]:50847 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751805Ab1AEXGk (ORCPT ); Wed, 5 Jan 2011 18:06:40 -0500 X-Mailbox-Line: From gregkh@clark.site Wed Jan 5 15:03:26 2011 Message-Id: <20110105230326.680530408@clark.site> User-Agent: quilt/0.48-11.2 Date: Wed, 05 Jan 2011 15:00:50 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jiri Slaby , Jiri Kosina , Antonio Ospite Subject: [32/49] HID: hidraw: fix window in hidraw_release In-Reply-To: <20110105230438.GA26241@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Jiri Slaby commit cb174681a9ececa6702f114b85bdf82144b6a5af upstream. [ Backport to .32.y by Antonio Ospite ] There is a window between hidraw_table check and its dereference. In that window, the device may be unplugged and removed form the system and we will then dereference NULL. Lock that place properly so that either we get NULL and jump out or we can work with real pointer. Signed-off-by: Jiri Slaby Signed-off-by: Jiri Kosina Signed-off-by: Antonio Ospite Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hidraw.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -211,11 +211,14 @@ static int hidraw_release(struct inode * unsigned int minor = iminor(inode); struct hidraw *dev; struct hidraw_list *list = file->private_data; + int ret; + mutex_lock(&minors_lock); if (!hidraw_table[minor]) { printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n", minor); - return -ENODEV; + ret = -ENODEV; + goto unlock; } list_del(&list->node); @@ -229,10 +232,12 @@ static int hidraw_release(struct inode * kfree(list->hidraw); } } - kfree(list); + ret = 0; +unlock: + mutex_unlock(&minors_lock); - return 0; + return ret; } static long hidraw_ioctl(struct file *file, unsigned int cmd,