From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59110 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932498AbeDVOSo (ORCPT ); Sun, 22 Apr 2018 10:18:44 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rodrigo Rivas Costa , Jiri Kosina Subject: [PATCH 4.4 81/97] HID: hidraw: Fix crash on HIDIOCGFEATURE with a destroyed device Date: Sun, 22 Apr 2018 15:53:59 +0200 Message-Id: <20180422135309.635020694@linuxfoundation.org> In-Reply-To: <20180422135304.577223025@linuxfoundation.org> References: <20180422135304.577223025@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Rodrigo Rivas Costa commit a955358d54695e4ad9f7d6489a7ac4d69a8fc711 upstream. Doing `ioctl(HIDIOCGFEATURE)` in a tight loop on a hidraw device and then disconnecting the device, or unloading the driver, can cause a NULL pointer dereference. When a hidraw device is destroyed it sets 0 to `dev->exist`. Most functions check 'dev->exist' before doing its work, but `hidraw_get_report()` was missing that check. Cc: stable@vger.kernel.org Signed-off-by: Rodrigo Rivas Costa Signed-off-by: Jiri Kosina Signed-off-by: Greg Kroah-Hartman --- drivers/hid/hidraw.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -197,6 +197,11 @@ static ssize_t hidraw_get_report(struct int ret = 0, len; unsigned char report_number; + if (!hidraw_table[minor] || !hidraw_table[minor]->exist) { + ret = -ENODEV; + goto out; + } + dev = hidraw_table[minor]->hid; if (!dev->ll_driver->raw_request) {