From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754126AbcHUPeR (ORCPT ); Sun, 21 Aug 2016 11:34:17 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:55691 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754027AbcHUPeN (ORCPT ); Sun, 21 Aug 2016 11:34:13 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Anthony Romano , Vlastimil Babka , Hugh Dickins , Brandon Philips , Andrew Morton , Linus Torvalds , Willy Tarreau Subject: [PATCH 3.10 045/180] tmpfs: don't undo fallocate past its last page Date: Sun, 21 Aug 2016 17:29:35 +0200 Message-Id: <1471793510-13022-46-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1471793510-13022-1-git-send-email-w@1wt.eu> References: <1471793510-13022-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: Willy Tarreau --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/shmem.c b/mm/shmem.c index 4e4a734..e163e40 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1950,7 +1950,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset, /* 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; } -- 2.8.0.rc2.1.gbe9624a