From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 4.6 197/203] tmpfs: dont undo fallocate past its last page Date: Mon, 25 Jul 2016 13:56:52 -0700 Message-Id: <20160725203437.442084208@linuxfoundation.org> In-Reply-To: <20160725203429.221747288@linuxfoundation.org> References: <20160725203429.221747288@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.6-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 @@ -2238,7 +2238,7 @@ static long shmem_fallocate(struct file /* Remove the !PageUptodate pages we added */ shmem_undo_range(inode, (loff_t)start << PAGE_SHIFT, - (loff_t)index << PAGE_SHIFT, true); + ((loff_t)index << PAGE_SHIFT) - 1, true); goto undone; }