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=-6.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 7B297C43387 for ; Thu, 20 Dec 2018 09:39:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C1AE20811 for ; Thu, 20 Dec 2018 09:39:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545298751; bh=7gMbO2YH8hCjRUVTK6xgeC9bZyFKIplnKnUxALmO66U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cl4YWBv/vpNhK9Cv3eC+1h309ONH3lIlVND9HaGxYGmJdQtlPkOvSl5Am/3Ngh2fe ueLOI2RmGP5j1T04QSrNd7XXlWVeKVDFK55wexz5peTM40I5fwAouy/s9J9OoQEc9l LljbQjbtGzMM/7nc79WR5zJzbR7pQZEBGK3KfWhE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732894AbeLTJiL (ORCPT ); Thu, 20 Dec 2018 04:38:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:54288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732084AbeLTJ0X (ORCPT ); Thu, 20 Dec 2018 04:26:23 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 4F577218C3; Thu, 20 Dec 2018 09:26:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545297982; bh=7gMbO2YH8hCjRUVTK6xgeC9bZyFKIplnKnUxALmO66U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=euP06A7K8J6UyeKFRxiOa/f7A682jnYxtgvSusBbCnqH8k6ULacRnKf0LAFeZQgKD mvOHAsOMNkO1h/0eHILtYaFGKD5ytjh0bU63OU2oBFX161WPL1aGkNYxUHxJA0vKz8 Uc696FggYqGgtxvOEfOVYdhqbrcrVeU0Fqq5q0aE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrea Arcangeli , syzbot+06c7092e7d71218a2c16@syzkaller.appspotmail.com, Mike Rapoport , Hugh Dickins , Peter Xu , Andrew Morton , Linus Torvalds Subject: [PATCH 4.14 04/72] userfaultfd: check VM_MAYWRITE was set after verifying the uffd is registered Date: Thu, 20 Dec 2018 10:18:03 +0100 Message-Id: <20181220085922.508932777@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20181220085922.332225035@linuxfoundation.org> References: <20181220085922.332225035@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrea Arcangeli commit 01e881f5a1fca4677e82733061868c6d6ea05ca7 upstream. Calling UFFDIO_UNREGISTER on virtual ranges not yet registered in uffd could trigger an harmless false positive WARN_ON. Check the vma is already registered before checking VM_MAYWRITE to shut off the false positive warning. Link: http://lkml.kernel.org/r/20181206212028.18726-2-aarcange@redhat.com Cc: Fixes: 29ec90660d68 ("userfaultfd: shmem/hugetlbfs: only allow to register VM_MAYWRITE vmas") Signed-off-by: Andrea Arcangeli Reported-by: syzbot+06c7092e7d71218a2c16@syzkaller.appspotmail.com Acked-by: Mike Rapoport Acked-by: Hugh Dickins Acked-by: Peter Xu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/userfaultfd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1567,7 +1567,6 @@ static int userfaultfd_unregister(struct cond_resched(); BUG_ON(!vma_can_userfault(vma)); - WARN_ON(!(vma->vm_flags & VM_MAYWRITE)); /* * Nothing to do: this vma is already registered into this @@ -1576,6 +1575,8 @@ static int userfaultfd_unregister(struct if (!vma->vm_userfaultfd_ctx.ctx) goto skip; + WARN_ON(!(vma->vm_flags & VM_MAYWRITE)); + if (vma->vm_start > start) start = vma->vm_start; vma_end = min(end, vma->vm_end);