Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030657AbbD1RcY (ORCPT ); Tue, 28 Apr 2015 13:32:24 -0400 Received: from mout.gmx.net ([212.227.17.22]:62705 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030347AbbD1RcW (ORCPT ); Tue, 28 Apr 2015 13:32:22 -0400 From: Heinrich Schuchardt To: Peter Chen Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Heinrich Schuchardt Subject: [PATCH 1/1 v2] drivers/usb/chipidea/debuc.c: avoid out of bound read Date: Tue, 28 Apr 2015 19:30:47 +0200 Message-Id: <1430242247-16620-1-git-send-email-xypron.glpk@gmx.de> X-Mailer: git-send-email 2.1.4 In-Reply-To: <20150428082222.GB32234@shlinux2> References: <20150428082222.GB32234@shlinux2> X-Provags-ID: V03:K0:JkjkNlZRJuIje7kGfvwNRBEbE0xUplZoWzF8dVN0vT8yES/LI6d sN7yvqnNV2O2jA/+HJ1kvWYrJroXaBWAnPMNP0Pvdbi2oP72tx4sj6ZMQr0kOyF/g7tpxp0 MW6KpALswqiJY32KePtFSQcCDJ0DkIiLTIP1q2wOop8I0QOxcYK/djST8V9ktLXLP9tU5C/ UCe6LaId02PmiZYPKyTEg== X-UI-Out-Filterresults: notjunk:1; Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1261 Lines: 42 A string written by the user may not be zero terminated. sscanf may read memory beyond the buffer if no zero byte is found. For testing build with CONFIG_USB_CHIPIDEA=y, CONFIG_USB_CHIPIDEA_DEBUG=y. Version 2: Use '\0' for char constant. Signed-off-by: Heinrich Schuchardt --- drivers/usb/chipidea/debug.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c index dfb05ed..ef08af3 100644 --- a/drivers/usb/chipidea/debug.c +++ b/drivers/usb/chipidea/debug.c @@ -88,9 +88,13 @@ static ssize_t ci_port_test_write(struct file *file, const char __user *ubuf, char buf[32]; int ret; - if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) + count = min_t(size_t, sizeof(buf) - 1, count); + if (copy_from_user(buf, ubuf, count)) return -EFAULT; + /* sscanf requires a zero terminated string */ + buf[count] = '\0'; + if (sscanf(buf, "%u", &mode) != 1) return -EINVAL; -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/