From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933522Ab1DNRrg (ORCPT ); Thu, 14 Apr 2011 13:47:36 -0400 Received: from mail.windriver.com ([147.11.1.11]:38603 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932892Ab1DNRr0 (ORCPT ); Thu, 14 Apr 2011 13:47:26 -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 103/209] HID: hidraw, fix a NULL pointer dereference in hidraw_write Date: Thu, 14 Apr 2011 13:42:13 -0400 Message-Id: <1302803039-9400-104-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 e42dee9a99a3ecd32b5c027e8f7411fb5bc11eb6 upstream. BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: [] hidraw_write+0x3b/0x116 [hid] [...] This is reproducible by disconnecting the device while userspace writes to dev node 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 | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 0db1a0f..9d3c663 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -106,11 +106,15 @@ out: static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) { unsigned int minor = iminor(file->f_path.dentry->d_inode); - /* FIXME: What stops hidraw_table going NULL */ - struct hid_device *dev = hidraw_table[minor]->hid; + struct hid_device *dev; __u8 *buf; int ret = 0; + if (!hidraw_table[minor]) + return -ENODEV; + + dev = hidraw_table[minor]->hid; + if (!dev->hid_output_raw_report) return -ENODEV; -- 1.7.4.4