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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,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 79D7EC606BF for ; Mon, 8 Jul 2019 14:37:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 48A9E21479 for ; Mon, 8 Jul 2019 14:37:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562596674; bh=oWp+oDcJJXv6d/8Lw2X3XDx1l88oBrL3Uk5WmOCPSkY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=iIRrcfg1kFIZubVTDqTS2fBvLlUtaFdz85KCsTdZQKPpEYRRkXuohj1VSObd79ZiS 1kMVXM+FGgKK0cuOpO0V3ycND/GdCvXGfiw8z9foy+scyqWR3zTVisE2pSXXvDuZ97 NJSP1ai9wW4xKTaAQZCo4iHmYEqKtB390DKpJkLk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729968AbfGHOhw (ORCPT ); Mon, 8 Jul 2019 10:37:52 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:38502 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728998AbfGHOhw (ORCPT ); Mon, 8 Jul 2019 10:37:52 -0400 Received: by mail-qt1-f193.google.com with SMTP id n11so18218116qtl.5 for ; Mon, 08 Jul 2019 07:37:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=xlxx8z2Kd6mbVhAes5Vdim+URDBLB+ELlLVS4awXZ9Y=; b=QCtZWFEv/LtisRrIoUoYOtwD3/m8z59j1MfwvEa140ZnPFZrcxcNolkffkei5eAXMV ZWmer8DsRRKIQZ6JjDANKYtq6RWKGK4Ico5sCJyye/vnoEfMvoqp7ZKNEd8cJqFRr2US kHONahrCz49ZK7/lxWQZqiaOWeZa9RmQPHx3LmHM+lYpHMqjF1nO76882BA93LL9B5VR cAVM7nuU8XeqD4d0QsfeiqHP4PuPO9oTic+mlxUMtkoVm9+FqIwg5WhwiwJlpD6DrcBP UqJxgKd0IRFYaKkLuMJXtO8YCnzkJYJ9i4SLoidzjGl26wOT64vM0whibmPGmxkQ24Xs s+fQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=xlxx8z2Kd6mbVhAes5Vdim+URDBLB+ELlLVS4awXZ9Y=; b=MrLpa0zCMO7u72JGg/S8mhyr3fOAtaQp6l6kQvUzuDtc0fMJa1KLD2L69b6WR5J2Bh 6Zzy/V7swycnpRl46ztkdSjtQUvRwEdqAMqfVT7HVzI4UkYdqrs0QvysS3SprFYVlu7g U71DUlxAITh1hO1Rx5AOybG7HHnzVtCoewlu28aKdX+tayuLQ61LbWnkycR8dKhbXgKr gYkurKErj5et5IfLHTwuRi74goG+04S8hIKia8YGCml+eWkJZ599SDoTosl8Ku1T8NuO 6Ec4y+JdMDdPOx5LGwE8YNEmQs+KBge35Y9DQRxaI3J8AB+WNLvT0Xih9/mN7yPS9+4n D8gg== X-Gm-Message-State: APjAAAXzaB6c2NB7JjeqJlAAV6xWnusROb7yIrSZJJQzjeS4j9kQJNC0 M2DMTibvWBji3R+SlP5XCEE= X-Google-Smtp-Source: APXvYqyxDMinPFx1mhUvSh89llFUSIQMspgV3DMd8UeIuHnZU0mc22OT2kYYzqlAu+Bq2GLeP16tTA== X-Received: by 2002:ac8:f3b:: with SMTP id e56mr14584643qtk.123.1562596671308; Mon, 08 Jul 2019 07:37:51 -0700 (PDT) Received: from localhost ([2620:10d:c091:500::2:fa50]) by smtp.gmail.com with ESMTPSA id 67sm7655862qkh.108.2019.07.08.07.37.50 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 08 Jul 2019 07:37:50 -0700 (PDT) Date: Mon, 8 Jul 2019 07:37:48 -0700 From: Tejun Heo To: Peng Wang Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] kernfs: fix potential null pointer dereference Message-ID: <20190708143748.GZ657710@devbig004.ftw2.facebook.com> References: <20190705134730.20833-1-rocking@whu.edu.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190705134730.20833-1-rocking@whu.edu.cn> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 05, 2019 at 09:47:30PM +0800, Peng Wang wrote: > diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c > index a387534c9577..ea3fc972c48b 100644 > --- a/fs/kernfs/dir.c > +++ b/fs/kernfs/dir.c > @@ -430,7 +430,7 @@ struct kernfs_node *kernfs_get_active(struct kernfs_node *kn) > */ > void kernfs_put_active(struct kernfs_node *kn) > { > - struct kernfs_root *root = kernfs_root(kn); > + struct kernfs_root *root; > int v; > > if (unlikely(!kn)) > @@ -442,6 +442,7 @@ void kernfs_put_active(struct kernfs_node *kn) > if (likely(v != KN_DEACTIVATED_BIAS)) > return; > > + root = kernfs_root(kn); > wake_up_all(&root->deactivate_waitq); Maybe just remove the root variable altogether? Other than that, Acked-by: Tejun Heo Thanks. -- tejun