Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752264AbbDQFkx (ORCPT ); Fri, 17 Apr 2015 01:40:53 -0400 Received: from mout.gmx.net ([212.227.15.19]:62271 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751014AbbDQFkp (ORCPT ); Fri, 17 Apr 2015 01:40:45 -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] drivers/usb/chipidea/debuc.c: avoid out of bound read Date: Fri, 17 Apr 2015 08:04:13 +0200 Message-Id: <1429250653-1626-1-git-send-email-xypron.glpk@gmx.de> X-Mailer: git-send-email 2.1.4 X-Provags-ID: V03:K0:Ys2JXNq/DRgvWUA0z07dW2pbzD6UR8nfrWrkNEEcgZPW/v18HGe gNMl4o06dVd0v7Nz5xrx00xasj+1Fs2ARyugJmPUuPuhbY/NVkJ4ngDL70aVPvoOVU587zU w0+h9MVeAC4prXyC70zVI6sOdV1swOLlQC99EawcLJpjAZ1sefg2kKwCyKpveaPEz70CsBH 7IPRDDlK7vRXzn9VTsTvA== 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: 1140 Lines: 37 A string written by the user may not be zero terminated. sscanf may read memory beyond the buffer if no zero byte is found. 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/