From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:33988 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728759AbeK3BdX (ORCPT ); Thu, 29 Nov 2018 20:33:23 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Janosch Frank , David Hildenbrand , Dan Carpenter Subject: [PATCH 4.14 094/100] s390/mm: Check for valid vma before zapping in gmap_discard Date: Thu, 29 Nov 2018 15:13:04 +0100 Message-Id: <20181129140106.874898228@linuxfoundation.org> In-Reply-To: <20181129140058.768942700@linuxfoundation.org> References: <20181129140058.768942700@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Janosch Frank commit 1843abd03250115af6cec0892683e70cf2297c25 upstream. Userspace could have munmapped the area before doing unmapping from the gmap. This would leave us with a valid vmaddr, but an invalid vma from which we would try to zap memory. Let's check before using the vma. Fixes: 1e133ab296f3 ("s390/mm: split arch/s390/mm/pgtable.c") Signed-off-by: Janosch Frank Reviewed-by: David Hildenbrand Reported-by: Dan Carpenter Message-Id: <20180816082432.78828-1-frankja@linux.ibm.com> Signed-off-by: Janosch Frank Signed-off-by: Greg Kroah-Hartman --- arch/s390/mm/gmap.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/s390/mm/gmap.c +++ b/arch/s390/mm/gmap.c @@ -689,6 +689,8 @@ void gmap_discard(struct gmap *gmap, uns vmaddr |= gaddr & ~PMD_MASK; /* Find vma in the parent mm */ vma = find_vma(gmap->mm, vmaddr); + if (!vma) + continue; size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK)); zap_page_range(vma, vmaddr, size); }