From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754654AbcGYVTM (ORCPT ); Mon, 25 Jul 2016 17:19:12 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:46619 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754649AbcGYVRr (ORCPT ); Mon, 25 Jul 2016 17:17:47 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anthony Romano , Vlastimil Babka , Hugh Dickins , Brandon Philips , Andrew Morton , Linus Torvalds Subject: [PATCH 4.4 143/146] tmpfs: dont undo fallocate past its last page Date: Mon, 25 Jul 2016 13:56:38 -0700 Message-Id: <20160725203527.342652472@linuxfoundation.org> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20160725203521.340401316@linuxfoundation.org> References: <20160725203521.340401316@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Anthony Romano commit b9b4bb26af017dbe930cd4df7f9b2fc3a0497bfe upstream. When fallocate is interrupted it will undo a range that extends one byte past its range of allocated pages. This can corrupt an in-use page by zeroing out its first byte. Instead, undo using the inclusive byte range. Fixes: 1635f6a74152f1d ("tmpfs: undo fallocation on failure") Link: http://lkml.kernel.org/r/1462713387-16724-1-git-send-email-anthony.romano@coreos.com Signed-off-by: Anthony Romano Cc: Vlastimil Babka Cc: Hugh Dickins Cc: Brandon Philips Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2155,7 +2155,7 @@ static long shmem_fallocate(struct file /* Remove the !PageUptodate pages we added */ shmem_undo_range(inode, (loff_t)start << PAGE_CACHE_SHIFT, - (loff_t)index << PAGE_CACHE_SHIFT, true); + ((loff_t)index << PAGE_CACHE_SHIFT) - 1, true); goto undone; }