From patchwork Wed Nov 6 19:04:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 11230887 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 84AED1986 for ; Wed, 6 Nov 2019 19:04:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5908C21882 for ; Wed, 6 Nov 2019 19:04:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="H5IPwGRG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728670AbfKFTEJ (ORCPT ); Wed, 6 Nov 2019 14:04:09 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:53930 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727410AbfKFTEJ (ORCPT ); Wed, 6 Nov 2019 14:04:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573067048; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=mWTSqOOTt3Dk2ZPvesbfsapc/5QXTzyY0nl7eR6Zqto=; b=H5IPwGRGnMVmVXMXRnJYf9j+trPtCon5B6RnCIR06KlMitfBCrTH5cIPnQgYV2gZTPYF7E Qpx89o2dBgVxZydikS9UGJMyz8+DNGXrrwgtMPg9QUrVlgwI//9zlpxeJUc5E8o4k7sYXi wcQr1+hL05e24tO3Qc2yJ9QAVLxWEMM= 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-434-y9o0P_5YOvyqcIpOWoYuDA-1; Wed, 06 Nov 2019 14:04:05 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9C63D800C72; Wed, 6 Nov 2019 19:04:03 +0000 (UTC) Received: from max.com (unknown [10.40.206.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3FD991001B35; Wed, 6 Nov 2019 19:04:02 +0000 (UTC) From: Andreas Gruenbacher To: linux-xfs@vger.kernel.org Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, Christoph Hellwig , Andreas Gruenbacher Subject: [PATCH] iomap: Fix overflow in iomap_page_mkwrite Date: Wed, 6 Nov 2019 20:04:00 +0100 Message-Id: <20191106190400.20969-1-agruenba@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-MC-Unique: y9o0P_5YOvyqcIpOWoYuDA-1 X-Mimecast-Spam-Score: 0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On architectures where ssize_t is wider than pgoff_t, the expression ((page->index + 1) << PAGE_SHIFT) can overflow. Rewrite to use the page offset, which we already compute here anyway. Signed-off-by: Andreas Gruenbacher Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong --- fs/iomap/buffered-io.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index e25901ae3ff4..a30ea7ecb790 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1040,20 +1040,19 @@ vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops) lock_page(page); size = i_size_read(inode); - if ((page->mapping != inode->i_mapping) || - (page_offset(page) > size)) { + offset = page_offset(page); + if (page->mapping != inode->i_mapping || offset > size) { /* We overload EFAULT to mean page got truncated */ ret = -EFAULT; goto out_unlock; } /* page is wholly or partially inside EOF */ - if (((page->index + 1) << PAGE_SHIFT) > size) + if (offset > size - PAGE_SIZE) length = offset_in_page(size); else length = PAGE_SIZE; - offset = page_offset(page); while (length > 0) { ret = iomap_apply(inode, offset, length, IOMAP_WRITE | IOMAP_FAULT, ops, page,