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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 52227C43387 for ; Tue, 18 Dec 2018 16:41:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1830E218A2 for ; Tue, 18 Dec 2018 16:41:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545151261; bh=1Lm//mzU2e0gxuE+a3YjC4vogDBirIO5eOvwbikJxGo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mS1rBo6VUtDcWZ2QV/83CtztpF9/S7JvR/csCbPqjIk29rmQgde64AImZuJb1ahrt KXpRl4BMhEMWTm/yuc3R0ehexJzdbgqyOjZCzP/YqQpTxY+cbRLCZ4vP3kYtn5UQwL BvKD/L7TLRMayPHJjj7bpNU9eBW8VN6qGLVnR2jQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727437AbeLRQlA (ORCPT ); Tue, 18 Dec 2018 11:41:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:38132 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727394AbeLRQkx (ORCPT ); Tue, 18 Dec 2018 11:40:53 -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 7D35C218A3; Tue, 18 Dec 2018 16:40:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545151253; bh=1Lm//mzU2e0gxuE+a3YjC4vogDBirIO5eOvwbikJxGo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xP78srxL32O2h0rxcJH40BOjuxQ+dGVw+RSVOHy9HDwKRGIuhrEVEB+M3cCUY6oN3 VuoEuHLiCwjDGzWJFvStrBPi9vpL3KttXxCe/c58osJ9JNxUdKAirknFXCY3WvrSQk hrEahlAqXZ7wnKQFDyTGxi7S0oG7WIvtVFmsHn1E= 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 4.19 12/44] userfaultfd: check VM_MAYWRITE was set after verifying the uffd is registered Date: Tue, 18 Dec 2018 17:39:24 +0100 Message-Id: <20181218163928.971029930@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20181218163927.119623235@linuxfoundation.org> References: <20181218163927.119623235@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 4.19-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 @@ -1566,7 +1566,6 @@ 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 @@ -1575,6 +1574,8 @@ 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);