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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 4D4C7C2D0E5 for ; Wed, 25 Mar 2020 19:25:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 20F5420719 for ; Wed, 25 Mar 2020 19:25:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="M9nO1NB9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727744AbgCYTZo (ORCPT ); Wed, 25 Mar 2020 15:25:44 -0400 Received: from mail-qk1-f195.google.com ([209.85.222.195]:46690 "EHLO mail-qk1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727328AbgCYTZn (ORCPT ); Wed, 25 Mar 2020 15:25:43 -0400 Received: by mail-qk1-f195.google.com with SMTP id u4so3837457qkj.13 for ; Wed, 25 Mar 2020 12:25:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=sPcjbSNBesC/NdOsDtyVCyVgM7ZVzEXz0TUVmUnVG4c=; b=M9nO1NB9KKYpUDscsJaXpuptFiRPZqCtWp6z3B43ZCTyT+9p4OAA3HymZ58sJjt3yh YvOycDVoEcmLr1PmtfLuZ49l9ixhR3AhisSZsg5y2OviJdCzqTchnZPLHmzryHBKx9Wv JNzvspTYoxzI97k3IDo14s74oifnGQH3PnW0B1alyBv7YqO8KvQ9zCBrFWFwrOmvgzrb nkSTcazSNy/XCpnUYg3RhhxaK2bNHKRj7jIUSAu7ZXk9I2/zn2bhvR8IHg4CtIDzXrGY 4PFS9h0B9gGoMTuMv4io4BVlYiqTkaLcT2ceuPCVRuBCwtCM3nC+EzjCEEZmbycX5+H5 bmcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=sPcjbSNBesC/NdOsDtyVCyVgM7ZVzEXz0TUVmUnVG4c=; b=EHmkhs6362Q5GWPncts7eHC5k164/1BVNt/7hdwR3U+E1LWBaSWSplUYGwj3eFw82a sxOQyiFugTYtdie27mSICxT2ALZsCIHUcdDgTUpD0PZnQSu3NMQl0MvgM5vyBeaqJqlm h5vcN3qMxuZCY41UaKmD4xwE3aEkfo5JwCZzlbDcqEDuP6zPgezk4lvTcKevwzNP7727 Etn9stdNTG0igV3un54hDPViJXNQM3shMXwIEuPrucxopTWsoO42gMMW3MYFRApBnHhz 4rq/PXcAQeor9PrTV3Gie/0GM8TTGa4+OTcqGF5/fEgIodSJVZU6snl+rVj6lXLndHEs R/oA== X-Gm-Message-State: ANhLgQ1oj4mXa/7Q2KPDhPSNX0ELE+vGLiWxBUvKySrM89ukOi2v9zUG NexNUHsRC7NPHk/goE5tojM= X-Google-Smtp-Source: ADFU+vuNGT8wOtdVZTntx/FEY5Czblcce9Wbj03L8QOWZ+/fH2bcLR89xgBDwQNnh+V63FrwWQqDhA== X-Received: by 2002:a37:8645:: with SMTP id i66mr4441647qkd.91.1585164342411; Wed, 25 Mar 2020 12:25:42 -0700 (PDT) Received: from quaco.ghostprotocols.net ([179.97.37.151]) by smtp.gmail.com with ESMTPSA id d185sm16747255qkf.46.2020.03.25.12.25.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Mar 2020 12:25:41 -0700 (PDT) From: Arnaldo Carvalho de Melo X-Google-Original-From: Arnaldo Carvalho de Melo Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id C8BD640F77; Wed, 25 Mar 2020 16:25:39 -0300 (-03) Date: Wed, 25 Mar 2020 16:25:39 -0300 To: Ian Rogers Cc: Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , John Garry , Jin Yao , Andi Kleen , Kan Liang , linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Stephane Eranian Subject: Re: [PATCH] perf parse-events: add defensive null check Message-ID: <20200325192539.GH14102@kernel.org> References: <20200325164022.41385-1-irogers@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200325164022.41385-1-irogers@google.com> X-Url: http://acmel.wordpress.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Wed, Mar 25, 2020 at 09:40:22AM -0700, Ian Rogers escreveu: > Terms may have a null config in which case a strcmp will segv. This can > be reproduced with: > perf stat -e '*/event=?,nr/' sleep 1 > Add a null check to avoid this. This was caught by LLVM's libfuzzer. Adding the NULL check doesn't hurt, I guess, but I coudln't repro it: [root@seventh ~]# perf stat -e '*/event=?,nr/' sleep 1 WARNING: multiple event parsing errors event syntax error: '*/event=?,nr/' \___ 'nr' is not usable in 'perf stat' Initial error: event syntax error: '*/event=?,nr/' \___ Cannot find PMU `*'. Missing kernel support? Run 'perf list' for a list of valid events Usage: perf stat [] [] -e, --event event selector. use 'perf list' to list available events [root@seventh ~]# Does this take place only when libfuzzer is being used? - Arnaldo > Signed-off-by: Ian Rogers > --- > tools/perf/util/pmu.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c > index 616fbda7c3fc..ef6a63f3d386 100644 > --- a/tools/perf/util/pmu.c > +++ b/tools/perf/util/pmu.c > @@ -984,12 +984,11 @@ static int pmu_resolve_param_term(struct parse_events_term *term, > struct parse_events_term *t; > > list_for_each_entry(t, head_terms, list) { > - if (t->type_val == PARSE_EVENTS__TERM_TYPE_NUM) { > - if (!strcmp(t->config, term->config)) { > - t->used = true; > - *value = t->val.num; > - return 0; > - } > + if (t->type_val == PARSE_EVENTS__TERM_TYPE_NUM && > + t->config && !strcmp(t->config, term->config)) { > + t->used = true; > + *value = t->val.num; > + return 0; > } > } > > -- > 2.25.1.696.g5e7596f4ac-goog > -- - Arnaldo