From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756260Ab0LHAr6 (ORCPT ); Tue, 7 Dec 2010 19:47:58 -0500 Received: from kroah.org ([198.145.64.141]:58566 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756311Ab0LHAr4 (ORCPT ); Tue, 7 Dec 2010 19:47:56 -0500 X-Mailbox-Line: From gregkh@clark.site Tue Dec 7 16:44:33 2010 Message-Id: <20101208004433.697737658@clark.site> User-Agent: quilt/0.48-11.2 Date: Tue, 07 Dec 2010 16:44:40 -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, Antonio Ospite , Jiri Kosina Subject: [094/127] HID: hidraw, fix a NULL pointer dereference in hidraw_ioctl In-Reply-To: <20101208004456.GA23578@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ From: Antonio Ospite commit d20d5ffab92f00188f360c44c791a5ffb988247c upstream. BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: [] hidraw_ioctl+0xfc/0x32c [hid] [...] This is reproducible by disconnecting the device while userspace does ioctl in a loop and doesn't check return values in order to exit the loop. Signed-off-by: Antonio Ospite Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hidraw.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -237,11 +237,16 @@ static long hidraw_ioctl(struct file *fi struct inode *inode = file->f_path.dentry->d_inode; unsigned int minor = iminor(inode); long ret = 0; - /* FIXME: What stops hidraw_table going NULL */ - struct hidraw *dev = hidraw_table[minor]; + struct hidraw *dev; void __user *user_arg = (void __user*) arg; lock_kernel(); + dev = hidraw_table[minor]; + if (!dev) { + ret = -ENODEV; + goto out; + } + switch (cmd) { case HIDIOCGRDESCSIZE: if (put_user(dev->hid->rsize, (int __user *)arg)) @@ -314,6 +319,7 @@ static long hidraw_ioctl(struct file *fi ret = -ENOTTY; } +out: unlock_kernel(); return ret; }