From patchwork Thu Sep 9 14:59:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12483387 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 7CE9AC433FE for ; Thu, 9 Sep 2021 15:00:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 670EB6113E for ; Thu, 9 Sep 2021 15:00:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236642AbhIIPBg (ORCPT ); Thu, 9 Sep 2021 11:01:36 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33444 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237343AbhIIPB3 (ORCPT ); Thu, 9 Sep 2021 11:01:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631199619; 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=dVKGaWY+racbC655LqIRlEVT602/lkSjwE1pL7UEtiWoWq3I7gzuhx+iHTA0aTTClKHi8N BOLdd/VOZmqSYKuS0WG/+pGUVNmxXIn7Sw5mqXJKQdJA3Fpg9eATDiGS825DiZndex5HTh WKU9IIZIjai/0cCmmIEavtR/DEv7fhg= 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-197-J-Q8Tv1KN0mvtRrQVZeeOA-1; Thu, 09 Sep 2021 11:00:18 -0400 X-MC-Unique: J-Q8Tv1KN0mvtRrQVZeeOA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 317161006AA0; Thu, 9 Sep 2021 15:00:17 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.192.233]) by smtp.corp.redhat.com (Postfix) with ESMTP id AF17B6F923; Thu, 9 Sep 2021 15:00:12 +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 Subject: [PATCH RFC 5/9] s390/uv: fully validate the VMA before calling follow_page() Date: Thu, 9 Sep 2021 16:59:41 +0200 Message-Id: <20210909145945.12192-6-david@redhat.com> In-Reply-To: <20210909145945.12192-1-david@redhat.com> References: <20210909145945.12192-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 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: Liam R. Howlett --- 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; /*