From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94859C4360F for ; Tue, 2 Apr 2019 13:47:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A4842146E for ; Tue, 2 Apr 2019 13:47:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732257AbfDBNrj (ORCPT ); Tue, 2 Apr 2019 09:47:39 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43052 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731403AbfDBNkE (ORCPT ); Tue, 2 Apr 2019 09:40:04 -0400 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hBJdw-0002oP-SF; Tue, 02 Apr 2019 14:40:01 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hBJdw-0004tf-3K; Tue, 02 Apr 2019 14:40:00 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Arjan van de Ven" , "Arnaldo Carvalho de Melo" , "Jiri Olsa" , "Adrian Hunter" , "Namhyung Kim" Date: Tue, 02 Apr 2019 14:38:27 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 40/99] perf svghelper: Fix unchecked usage of strncpy() In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.65-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Arnaldo Carvalho de Melo commit 2f5302533f306d5ee87bd375aef9ca35b91762cb upstream. The strncpy() function may leave the destination string buffer unterminated, better use strlcpy() that we have a __weak fallback implementation for systems without it. In this specific case this would only happen if fgets() was buggy, as its man page states that it should read one less byte than the size of the destination buffer, so that it can put the nul byte at the end of it, so it would never copy 255 non-nul chars, as fgets reads into the orig buffer at most 254 non-nul chars and terminates it. But lets just switch to strlcpy to keep the original intent and silence the gcc 8.2 warning. This fixes this warning on an Alpine Linux Edge system with gcc 8.2: In function 'cpu_model', inlined from 'svg_cpu_box' at util/svghelper.c:378:2: util/svghelper.c:337:5: error: 'strncpy' output may be truncated copying 255 bytes from a string of length 255 [-Werror=stringop-truncation] strncpy(cpu_m, &buf[13], 255); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Arjan van de Ven Fixes: f48d55ce7871 ("perf: Add a SVG helper library file") Link: https://lkml.kernel.org/n/tip-xzkoo0gyr56gej39ltivuh9g@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Ben Hutchings --- tools/perf/util/svghelper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/tools/perf/util/svghelper.c +++ b/tools/perf/util/svghelper.c @@ -257,7 +257,7 @@ static char *cpu_model(void) if (file) { while (fgets(buf, 255, file)) { if (strstr(buf, "model name")) { - strncpy(cpu_m, &buf[13], 255); + strlcpy(cpu_m, &buf[13], 255); break; } }