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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 8337DC3A5A2 for ; Thu, 22 Aug 2019 17:25:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5031C2341E for ; Thu, 22 Aug 2019 17:25:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494707; bh=q/HJ4AnTe5uwkoNVoSG0CmxitIRVdUXr5MAmYEai4A0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=087ZSQ+IjWAbRlutUEAfuFNK+79C2FN7BZ155esRhZWdppNVcM+VE25yrzRcvtjbH E2sF7OxYVsb/AZIfb+nYz/65DAyA67a38XzcDrDdXysBzWkLmxi60UGPQaS1NLZIcl Lknf5kSvCo0wt6EraRpahn3G5X6qRQ+OrCfVYS+Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391835AbfHVRZG (ORCPT ); Thu, 22 Aug 2019 13:25:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:46670 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404291AbfHVRYm (ORCPT ); Thu, 22 Aug 2019 13:24:42 -0400 Received: from localhost (wsip-184-188-36-2.sd.sd.cox.net [184.188.36.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2EE1123405; Thu, 22 Aug 2019 17:24:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494681; bh=q/HJ4AnTe5uwkoNVoSG0CmxitIRVdUXr5MAmYEai4A0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DHIag41GfVk1r/w+NwMoYN5lNQ3ScclcEf5Z7i+7BLA+BGxOwYv79bQEg8TxN2lpf MfVKArEb7lhiYMdcm3Hey00d74lUlaEYczZquhsjtV9jIpPug3+/bi0DeAMQUvme0V 0YuUIyxFUdkga92uNuFASgLEhIhqdDROGDa/4H+8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vince Weaver , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Peter Zijlstra , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 4.14 26/71] perf header: Fix divide by zero error if f_header.attr_size==0 Date: Thu, 22 Aug 2019 10:19:01 -0700 Message-Id: <20190822171728.886027331@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190822171726.131957995@linuxfoundation.org> References: <20190822171726.131957995@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 7622236ceb167aa3857395f9bdaf871442aa467e ] So I have been having lots of trouble with hand-crafted perf.data files causing segfaults and the like, so I have started fuzzing the perf tool. First issue found: If f_header.attr_size is 0 in the perf.data file, then perf will crash with a divide-by-zero error. Committer note: Added a pr_err() to tell the user why the command failed. Signed-off-by: Vince Weaver Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1907231100440.14532@macbook-air Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/util/header.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index c892a28e7b048..baec3e9833256 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2901,6 +2901,13 @@ int perf_session__read_header(struct perf_session *session) file->path); } + if (f_header.attr_size == 0) { + pr_err("ERROR: The %s file's attr size field is 0 which is unexpected.\n" + "Was the 'perf record' command properly terminated?\n", + file->path); + return -EINVAL; + } + nr_attrs = f_header.attrs.size / f_header.attr_size; lseek(fd, f_header.attrs.offset, SEEK_SET); -- 2.20.1