From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933503Ab1DNRrb (ORCPT ); Thu, 14 Apr 2011 13:47:31 -0400 Received: from mail.windriver.com ([147.11.1.11]:38578 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933465Ab1DNRrZ (ORCPT ); Thu, 14 Apr 2011 13:47:25 -0400 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Antonio Ospite , Jiri Kosina , Paul Gortmaker Subject: [34-longterm 102/209] HID: hidraw, fix a NULL pointer dereference in hidraw_ioctl Date: Thu, 14 Apr 2011 13:42:12 -0400 Message-Id: <1302803039-9400-103-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1302803039-9400-1-git-send-email-paul.gortmaker@windriver.com> References: <1302803039-9400-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Antonio Ospite ===================================================================== | This is a commit scheduled for the next v2.6.34 longterm release. | | If you see a problem with using this for longterm, please comment.| ===================================================================== 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. [PG: slightly/trivially reworked for backport to 34] Signed-off-by: Antonio Ospite Signed-off-by: Jiri Kosina Signed-off-by: Paul Gortmaker --- drivers/hid/hidraw.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 6eadf1a..0db1a0f 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -243,6 +243,11 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd, void __user *user_arg = (void __user*) arg; lock_kernel(); + if (!dev) { + ret = -ENODEV; + goto out; + } + switch (cmd) { case HIDIOCGRDESCSIZE: if (put_user(dev->hid->rsize, (int __user *)arg)) @@ -315,6 +320,7 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd, ret = -ENOTTY; } +out: unlock_kernel(); return ret; } -- 1.7.4.4