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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 8D80AC433E9 for ; Tue, 26 Jan 2021 06:02:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EF9122AAC for ; Tue, 26 Jan 2021 06:02:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728856AbhAZGCC (ORCPT ); Tue, 26 Jan 2021 01:02:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:45212 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728739AbhAYNZt (ORCPT ); Mon, 25 Jan 2021 08:25:49 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C084822E03; Mon, 25 Jan 2021 13:24:48 +0000 (UTC) Subject: Re: [PATCH] m68k: let clk_enable() return immediately if clk is NULL To: Defang Bo , geert@linux-m68k.org Cc: linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org References: <1609121265-207018-1-git-send-email-bodefang@126.com> From: Greg Ungerer Message-ID: <963a69d9-34ac-085b-3756-95cc376fb7ca@linux-m68k.org> Date: Mon, 25 Jan 2021 23:24:45 +1000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <1609121265-207018-1-git-send-email-bodefang@126.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-m68k@vger.kernel.org Hi Defang, On 28/12/20 12:07 pm, Defang Bo wrote: > Similar to commit<742859adc721>("m68k: let clk_disable() return immediately if clk is NULL"). > there should be a check for clk to prevent NULL pointer dereference. > > Signed-off-by: Defang Bo I have applied this to the m68knommu git tree, for-next branch - with blank line added as per Geert's suggestion. Regards Greg > --- > arch/m68k/coldfire/clk.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/arch/m68k/coldfire/clk.c b/arch/m68k/coldfire/clk.c > index 7bc666e..6decd11 100644 > --- a/arch/m68k/coldfire/clk.c > +++ b/arch/m68k/coldfire/clk.c > @@ -90,6 +90,9 @@ EXPORT_SYMBOL(clk_get); > int clk_enable(struct clk *clk) > { > unsigned long flags; > + if (!clk) > + return -EINVAL; > + > spin_lock_irqsave(&clk_lock, flags); > if ((clk->enabled++ == 0) && clk->clk_ops) > clk->clk_ops->enable(clk); >