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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 AD537C43381 for ; Wed, 6 Mar 2019 10:17:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8787B20840 for ; Wed, 6 Mar 2019 10:17:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730242AbfCFKRb (ORCPT ); Wed, 6 Mar 2019 05:17:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:52830 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730170AbfCFKRV (ORCPT ); Wed, 6 Mar 2019 05:17:21 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 E397420828; Wed, 6 Mar 2019 10:17:20 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.92-RC5) (envelope-from ) id 1h1Tbz-0002A9-Tp; Wed, 06 Mar 2019 05:17:19 -0500 Message-Id: <20190306101719.811308335@goodmis.org> User-Agent: quilt/0.65 Date: Wed, 06 Mar 2019 05:16:59 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Tom Zanussi Subject: [for-next][PATCH 2/2] tracing: Use strncpy instead of memcpy when copying comm in trace.c References: <20190306101657.474580583@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tom Zanussi Because there may be random garbage beyond a string's null terminator, code that might use the entire comm array e.g. histogram keys, can give unexpected results if that garbage is copied in too, so avoid that possibility by using strncpy instead of memcpy. Link: http://lkml.kernel.org/r/1d6ebac26570c2a29ce9fb575379f17ef5c8b81b.1551802084.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Suggested-by: Steven Rostedt (VMware) Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3835f7ed3293..e9cc47e59d25 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1497,7 +1497,7 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) max_data->critical_start = data->critical_start; max_data->critical_end = data->critical_end; - memcpy(max_data->comm, tsk->comm, TASK_COMM_LEN); + strncpy(max_data->comm, tsk->comm, TASK_COMM_LEN); max_data->pid = tsk->pid; /* * If tsk == current, then use current_uid(), as that does not use @@ -1923,7 +1923,7 @@ static inline char *get_saved_cmdlines(int idx) static inline void set_cmdline(int idx, const char *cmdline) { - memcpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN); + strncpy(get_saved_cmdlines(idx), cmdline, TASK_COMM_LEN); } static int allocate_cmdlines_buffer(unsigned int val, -- 2.20.1