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=-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=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 A9BBAC433EF for ; Thu, 9 Sep 2021 15:01:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8BE24611B0 for ; Thu, 9 Sep 2021 15:01:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239687AbhIIPCN (ORCPT ); Thu, 9 Sep 2021 11:02:13 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:20055 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239952AbhIIPBz (ORCPT ); Thu, 9 Sep 2021 11:01:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631199646; 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=AFQ+PFFzuCsI2iNiDGJPyhOhhFIVbgjHojitNDzOvDA=; b=aXciQm1i7cNDdVEzxhTmSTgn7IWN3SSn/Aqa7h4AJsmV2gptKCQs20/hM5fGnHtNbFIubI Qfoh9V5fhwMvBsMm/IkVFddg5kj83HM2vnjpfi5aOfJa8JDmD+IrMdvVXSOX+BB17WvVUS dUpmDYpRTTgTCkbXezLfcjMLZQy+2Fo= 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-537-bR5dBWpKMIKV4m9D_tlJ8Q-1; Thu, 09 Sep 2021 11:00:42 -0400 X-MC-Unique: bR5dBWpKMIKV4m9D_tlJ8Q-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 A47FD8018A9; Thu, 9 Sep 2021 15:00:41 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.192.233]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7C75D6F923; Thu, 9 Sep 2021 15:00:17 +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 6/9] s390/pci_mmio: fully validate the VMA before calling follow_pte() Date: Thu, 9 Sep 2021 16:59:42 +0200 Message-Id: <20210909145945.12192-7-david@redhat.com> In-Reply-To: <20210909145945.12192-1-david@redhat.com> References: <20210909145945.12192-1-david@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-s390@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: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") Signed-off-by: David Hildenbrand --- arch/s390/pci/pci_mmio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c index ae683aa623ac..c5b35ea129cf 100644 --- a/arch/s390/pci/pci_mmio.c +++ b/arch/s390/pci/pci_mmio.c @@ -159,7 +159,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_write, unsigned long, mmio_addr, mmap_read_lock(current->mm); ret = -EINVAL; - vma = find_vma(current->mm, mmio_addr); + vma = vma_lookup(current->mm, mmio_addr); if (!vma) goto out_unlock_mmap; if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) @@ -298,7 +298,7 @@ SYSCALL_DEFINE3(s390_pci_mmio_read, unsigned long, mmio_addr, mmap_read_lock(current->mm); ret = -EINVAL; - vma = find_vma(current->mm, mmio_addr); + vma = vma_lookup(current->mm, mmio_addr); if (!vma) goto out_unlock_mmap; if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) -- 2.31.1