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=-6.8 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 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 770A8C5ACD8 for ; Wed, 18 Mar 2020 11:02:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4907B20772 for ; Wed, 18 Mar 2020 11:02:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584529328; bh=ZNJbZkH0nXoHrj4DDwLg8d1qU7rSUHWk+hrUrCsVZWI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=cnkxZzyT4KnY/VCCVXYZXXpApZD0vAeJUoQVtaqbgd58N3fu6r355LLlx2EEYmEmv TjThFpuD2VVWnDyhO5hynMjNzMecmFOFdyG9wSGKQcNqvejEKxBgzLKgIShuJSFH1m sR/cjiEHYjrt13ycCASa2NKoI+Q1SnvpMGVXEwyY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727736AbgCRLCH (ORCPT ); Wed, 18 Mar 2020 07:02:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:47810 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727687AbgCRLCG (ORCPT ); Wed, 18 Mar 2020 07:02:06 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 BAA0E2076D; Wed, 18 Mar 2020 11:02:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584529326; bh=ZNJbZkH0nXoHrj4DDwLg8d1qU7rSUHWk+hrUrCsVZWI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=z1anWoqPAz0ydzDH4yHNE+g9oIyu5kuia5JrJZB6ql+zFhErDrFEJaML4T/jNdWXb CG6BzUJIFjNncmVTqoo9xd+U9Dn0jRNIeRdll160Q0bp96E8CyZSCa5o9Y9JWXGc/0 vWRLbmvfUqjoPGSF8WA48HQnwDDF9WEgbzaS5r8c= Date: Wed, 18 Mar 2020 12:02:04 +0100 From: Greg Kroah-Hartman To: Xiyu Yang Cc: Arnd Bergmann , Xin Tan , Alexios Zavras , Vishnu DASA , Thomas Gleixner , Allison Randal , Ira Weiny , Mike Marshall , linux-kernel@vger.kernel.org, yuanxzhang@fudan.edu.cn, kjlu@umn.edu Subject: Re: [PATCH] VMCI: Fix NULL pointer dereference on context ptr Message-ID: <20200318110204.GB2305113@kroah.com> References: <1584426607-89366-1-git-send-email-xiyuyang19@fudan.edu.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1584426607-89366-1-git-send-email-xiyuyang19@fudan.edu.cn> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 17, 2020 at 02:29:57PM +0800, Xiyu Yang wrote: > The refcount wrapper function vmci_ctx_get() may return NULL > context ptr. Thus, we need to add a NULL pointer check > before its dereference. > > Signed-off-by: Xiyu Yang > Signed-off-by: Xin Tan > --- > drivers/misc/vmw_vmci/vmci_context.c | 2 ++ > drivers/misc/vmw_vmci/vmci_queue_pair.c | 17 +++++++++++------ > 2 files changed, 13 insertions(+), 6 deletions(-) > > diff --git a/drivers/misc/vmw_vmci/vmci_context.c b/drivers/misc/vmw_vmci/vmci_context.c > index 16695366ec92..a20878fba374 100644 > --- a/drivers/misc/vmw_vmci/vmci_context.c > +++ b/drivers/misc/vmw_vmci/vmci_context.c > @@ -898,6 +898,8 @@ void vmci_ctx_rcv_notifications_release(u32 context_id, > bool success) > { > struct vmci_ctx *context = vmci_ctx_get(context_id); > + if (context == NULL) > + return; Same comment as on your other patch. And is this a v2? > > spin_lock(&context->lock); > if (!success) { > diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c > index 8531ae781195..2ecb22d08692 100644 > --- a/drivers/misc/vmw_vmci/vmci_queue_pair.c > +++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c > @@ -1575,11 +1575,14 @@ static int qp_broker_attach(struct qp_broker_entry *entry, > */ > > create_context = vmci_ctx_get(entry->create_id); > - supports_host_qp = vmci_ctx_supports_host_qp(create_context); > - vmci_ctx_put(create_context); > + if (!create_context) { > + supports_host_qp = > + vmci_ctx_supports_host_qp(create_context); > + vmci_ctx_put(create_context); > > - if (!supports_host_qp) > - return VMCI_ERROR_INVALID_RESOURCE; > + if (!supports_host_qp) > + return VMCI_ERROR_INVALID_RESOURCE; > + } > } > > if ((entry->qp.flags & ~VMCI_QP_ASYMM) != (flags & ~VMCI_QP_ASYMM_PEER)) > @@ -1808,7 +1811,8 @@ static int qp_alloc_host_work(struct vmci_handle *handle, > pr_devel("queue pair broker failed to alloc (result=%d)\n", > result); > } > - vmci_ctx_put(context); > + if (context) > + vmci_ctx_put(context); can't vmci_ctx_put() take a NULL pointer? If not, fix this that way please. thanks, greg k-h