From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752410AbaAQJtZ (ORCPT ); Fri, 17 Jan 2014 04:49:25 -0500 Received: from mx0.aculab.com ([213.249.233.131]:39296 "HELO mx0.aculab.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752131AbaAQJsZ convert rfc822-to-8bit (ORCPT ); Fri, 17 Jan 2014 04:48:25 -0500 From: David Laight To: "'Chen-Yu Tsai'" , Johannes Berg , "David S. Miller" CC: "netdev@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-sunxi@googlegroups.com" , Maxime Ripard , "linux-wireless@vger.kernel.org" Subject: RE: [PATCH RFC 1/6] net: rfkill: gpio: fix gpio name buffer size off by 1 Thread-Topic: [PATCH RFC 1/6] net: rfkill: gpio: fix gpio name buffer size off by 1 Thread-Index: AQHPE0+5GjqUl9o9BUy7yae5v6yQmpqIqomg Date: Fri, 17 Jan 2014 09:46:08 +0000 Message-ID: <063D6719AE5E284EB5DD2968C1650D6D45EA9D@AcuExch.aculab.com> References: <1389941251-32692-1-git-send-email-wens@csie.org> <1389941251-32692-2-git-send-email-wens@csie.org> In-Reply-To: <1389941251-32692-2-git-send-email-wens@csie.org> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.202.99.200] Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chen-Yu Tsai > snprintf should be passed the complete size of the buffer, including > the space for '\0'. The previous code resulted in the *_reset and > *_shutdown strings being truncated. ... > diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c ... > - snprintf(rfkill->reset_name, len + 6 , "%s_reset", rfkill->name); > - snprintf(rfkill->shutdown_name, len + 9, "%s_shutdown", rfkill->name); > + snprintf(rfkill->reset_name, len + 7 , "%s_reset", rfkill->name); > + snprintf(rfkill->shutdown_name, len + 10, "%s_shutdown", rfkill->name); I can't find the context for the above, but they look very dubious. I'd expect: snprintf(foo, sizeof foo, ...). If you are trying to truncate rfkill->name you need to use %.*s. David