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 BDA83C3A5A1 for ; Thu, 22 Aug 2019 17:41:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9637120870 for ; Thu, 22 Aug 2019 17:41:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566495693; bh=lP9m1NorUH5z/y3KWy07mtIG+q/fbsq/E5dtd35zv0E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KI4lIkz7vhzuuqsl5UHPJvco/LHfjftOWt1tdxc/2bNS9dfTzjxTGMwYjL2E4sPfP FVYiPIVE4aftoBcCjthd1UlAX0IH/9bCO2mw9S+ZcXBaxrQUpauNlMoXevj7VcODyw yrK8aGU2CU+PTGanGfKA/e7tPGSyKVxtxmtOthkY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392383AbfHVRlc (ORCPT ); Thu, 22 Aug 2019 13:41:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:44776 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391762AbfHVRX6 (ORCPT ); Thu, 22 Aug 2019 13:23:58 -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 2E7A621743; Thu, 22 Aug 2019 17:23:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494637; bh=lP9m1NorUH5z/y3KWy07mtIG+q/fbsq/E5dtd35zv0E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sLkzJyb05u55xwBhUtGh+JLqGH/XQpCQ0HV+cs4dO48ASv5CoJLNTSTletxwdvfQ/ OD9yi2clKuoMSTcByJT1PWqPOV7DYcABjjuiH55+E2QrQVALEk0/yvyA6J7ajPlvQ5 BmuabPb6IZWJzJhDi9hauZyDbyD1AoLlRbj/btuY= 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 4.9 070/103] perf header: Fix divide by zero error if f_header.attr_size==0 Date: Thu, 22 Aug 2019 10:18:58 -0700 Message-Id: <20190822171731.710829593@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190822171728.445189830@linuxfoundation.org> References: <20190822171728.445189830@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 283148104ffbe..693dcd4ea6a38 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2854,6 +2854,13 @@ 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