From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45822 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933798AbdJJT6k (ORCPT ); Tue, 10 Oct 2017 15:58:40 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicolai Stange Subject: [PATCH 4.9 081/105] driver core: platform: Dont read past the end of "driver_override" buffer Date: Tue, 10 Oct 2017 21:50:52 +0200 Message-Id: <20171010192546.233749068@linuxfoundation.org> In-Reply-To: <20171010192533.717049376@linuxfoundation.org> References: <20171010192533.717049376@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicolai Stange commit bf563b01c2895a4bfd1a29cc5abc67fe706ecffd upstream. When printing the driver_override parameter when it is 4095 and 4094 bytes long, the printing code would access invalid memory because we need count+1 bytes for printing. Reject driver_override values of these lengths in driver_override_store(). This is in close analogy to commit 4efe874aace5 ("PCI: Don't read past the end of sysfs "driver_override" buffer") from Sasha Levin. Fixes: 3d713e0e382e ("driver core: platform: add device binding path 'driver_override'") Signed-off-by: Nicolai Stange Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -858,7 +858,8 @@ static ssize_t driver_override_store(str struct platform_device *pdev = to_platform_device(dev); char *driver_override, *old, *cp; - if (count > PATH_MAX) + /* We need to keep extra room for a newline */ + if (count >= (PAGE_SIZE - 1)) return -EINVAL; driver_override = kstrndup(buf, count, GFP_KERNEL);