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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 AC3F7C43381 for ; Tue, 5 Mar 2019 16:12:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 79A5A208E4 for ; Tue, 5 Mar 2019 16:12:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551802334; bh=kMyvZn/EeojJXgkRvBvUeq4iRMH9ghlPFbl/FskKIIE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:In-Reply-To: References:List-ID:From; b=ot03XrDuuu43rBXjBUgE1p4yPKcFPKg+weHw/QJCx9t/lK+VucLk9yO4u0xv19XX0 mkm3jhm7xdL4J60R7kl7yQ6ajZtp5rV3D5pebKcwi+Hss2VT5xku7Pv4HTtguUV9vA BqEFILEmdEUzIcuNzZWsa0W2ZwifrfNm1NktRJWc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727312AbfCEQMM (ORCPT ); Tue, 5 Mar 2019 11:12:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:40382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726221AbfCEQMJ (ORCPT ); Tue, 5 Mar 2019 11:12:09 -0500 Received: from localhost.localdomain (c-98-220-238-81.hsd1.il.comcast.net [98.220.238.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0349D2171F; Tue, 5 Mar 2019 16:12:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551802329; bh=kMyvZn/EeojJXgkRvBvUeq4iRMH9ghlPFbl/FskKIIE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:In-Reply-To: References:From; b=EObyEvXWQrEWaTF5kGTaly7COdu/ra7o60ix+Y0kjw+gCST6jOTMZZv4CLSdtdET+ mBhbg3B1x6gdnJ8MEoXQ5zbrrrjFoqWIEbTY/appWiA1QSJbKOsZMX4sRQrpTXZf9u jBrgwCsiLf63QNMeSK2r7YLpqNOO66mEV8+2d1Bc= From: Tom Zanussi To: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH 2/2] tracing: Use strncpy instead of memcpy when copying comm in trace.c Date: Tue, 5 Mar 2019 10:12:00 -0600 Message-Id: <1d6ebac26570c2a29ce9fb575379f17ef5c8b81b.1551802084.git.tom.zanussi@linux.intel.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: References: In-Reply-To: References: 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. Signed-off-by: Tom Zanussi Suggested-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, -- 2.14.1