From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id 181A76B027B for ; Wed, 16 Nov 2016 12:29:56 -0500 (EST) Received: by mail-pg0-f72.google.com with SMTP id 3so159489103pgd.3 for ; Wed, 16 Nov 2016 09:29:56 -0800 (PST) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTPS id a84si5667342pfe.117.2016.11.16.09.29.55 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 16 Nov 2016 09:29:55 -0800 (PST) Subject: [PATCH] device-dax: fail all private mapping attempts From: Dan Williams Date: Wed, 16 Nov 2016 09:26:53 -0800 Message-ID: <147931721349.37471.4835899844582504197.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: linux-nvdimm@lists.01.org Cc: linux-mm@kvack.org, Dave Hansen , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Pawel Lebioda The device-dax implementation originally tried to be tricky and allow private read-only mappings, but in the process allowed writable MAP_PRIVATE + MAP_NORESERVE mappings. For simplicity and predictability just fail all private mapping attempts since device-dax memory is statically allocated and will never support overcommit. Cc: Cc: Dave Hansen Fixes: dee410792419 ("/dev/dax, core: file operations and dax-mmap") Reported-by: Pawel Lebioda Signed-off-by: Dan Williams --- drivers/dax/dax.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dax/dax.c b/drivers/dax/dax.c index 0e499bfca41c..3d94ff20fdca 100644 --- a/drivers/dax/dax.c +++ b/drivers/dax/dax.c @@ -270,8 +270,8 @@ static int check_vma(struct dax_dev *dax_dev, struct vm_area_struct *vma, if (!dax_dev->alive) return -ENXIO; - /* prevent private / writable mappings from being established */ - if ((vma->vm_flags & (VM_NORESERVE|VM_SHARED|VM_WRITE)) == VM_WRITE) { + /* prevent private mappings from being established */ + if ((vma->vm_flags & VM_SHARED) != VM_SHARED) { dev_info(dev, "%s: %s: fail, attempted private mapping\n", current->comm, func); return -EINVAL; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org