From patchwork Thu Sep 9 16:22:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12483441 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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 E6877C433FE for ; Thu, 9 Sep 2021 16:23:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3640611CC for ; Thu, 9 Sep 2021 16:23:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238050AbhIIQZC (ORCPT ); Thu, 9 Sep 2021 12:25:02 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:55322 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236758AbhIIQYw (ORCPT ); Thu, 9 Sep 2021 12:24:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631204622; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XLdqt4rseRM/GIF92UYXv6b/tK6ZasqjgOzH1i0jC0Y=; b=Afd+zzcPwkXWFq+yYB8hAz3zSdNh7u5RabTv3TRF+B2utAYK9e6i5yZ13ddQq3Rh4dkMIl R9w+mzWbeSpro1u41+1XFkXnkqZq9wOOMt/d8mtYCqett2s+cY5GjqgvP1es9HwNxqNO0k PivDrRO4Q13rz6Qrrry/C9pvtVvwpmI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-249-dD2LMHwWPuOGAojgNHBPhg-1; Thu, 09 Sep 2021 12:23:42 -0400 X-MC-Unique: dD2LMHwWPuOGAojgNHBPhg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EC3BC802E3F; Thu, 9 Sep 2021 16:23:10 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.192.233]) by smtp.corp.redhat.com (Postfix) with ESMTP id BC80C77718; Thu, 9 Sep 2021 16:23:07 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-s390@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, David Hildenbrand , Christian Borntraeger , Janosch Frank , Cornelia Huck , Claudio Imbrenda , Heiko Carstens , Vasily Gorbik , Niklas Schnelle , Gerald Schaefer , Ulrich Weigand Subject: [PATCH resend RFC 5/9] s390/uv: fully validate the VMA before calling follow_page() Date: Thu, 9 Sep 2021 18:22:44 +0200 Message-Id: <20210909162248.14969-6-david@redhat.com> In-Reply-To: <20210909162248.14969-1-david@redhat.com> References: <20210909162248.14969-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org We should not walk/touch page tables outside of VMA boundaries when holding only the mmap sem in read mode. Evil user space can modify the VMA layout just before this function runs and e.g., trigger races with page table removal code since commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap"). find_vma() does not check if the address is >= the VMA start address; use vma_lookup() instead. Fixes: 214d9bbcd3a6 ("s390/mm: provide memory management functions for protected KVM guests") Signed-off-by: David Hildenbrand Reviewed-by: Claudio Imbrenda --- arch/s390/kernel/uv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c index aeb0a15bcbb7..193205fb2777 100644 --- a/arch/s390/kernel/uv.c +++ b/arch/s390/kernel/uv.c @@ -227,7 +227,7 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb) uaddr = __gmap_translate(gmap, gaddr); if (IS_ERR_VALUE(uaddr)) goto out; - vma = find_vma(gmap->mm, uaddr); + vma = vma_lookup(gmap->mm, uaddr); if (!vma) goto out; /*