From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760820Ab2BJW7l (ORCPT ); Fri, 10 Feb 2012 17:59:41 -0500 Received: from mail-pw0-f46.google.com ([209.85.160.46]:42369 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932736Ab2BJWop (ORCPT ); Fri, 10 Feb 2012 17:44:45 -0500 MIME-Version: 1.0 Message-Id: <20120210223443.021194570@clark.kroah.org> User-Agent: quilt/0.51-15.1 Date: Fri, 10 Feb 2012 14:33:35 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Li Wang , Yunchuan Wen , Cong Wang , Tyler Hicks Subject: [patch 31/55] eCryptfs: Infinite loop due to overflow in ecryptfs_write() In-Reply-To: <20120210223500.GA24178@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Wang commit 684a3ff7e69acc7c678d1a1394fe9e757993fd34 upstream. ecryptfs_write() can enter an infinite loop when truncating a file to a size larger than 4G. This only happens on architectures where size_t is represented by 32 bits. This was caused by a size_t overflow due to it incorrectly being used to store the result of a calculation which uses potentially large values of type loff_t. [tyhicks@canonical.com: rewrite subject and commit message] Signed-off-by: Li Wang Signed-off-by: Yunchuan Wen Reviewed-by: Cong Wang Signed-off-by: Tyler Hicks Signed-off-by: Greg Kroah-Hartman --- fs/ecryptfs/read_write.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/fs/ecryptfs/read_write.c +++ b/fs/ecryptfs/read_write.c @@ -130,7 +130,7 @@ int ecryptfs_write(struct inode *ecryptf pgoff_t ecryptfs_page_idx = (pos >> PAGE_CACHE_SHIFT); size_t start_offset_in_page = (pos & ~PAGE_CACHE_MASK); size_t num_bytes = (PAGE_CACHE_SIZE - start_offset_in_page); - size_t total_remaining_bytes = ((offset + size) - pos); + loff_t total_remaining_bytes = ((offset + size) - pos); if (fatal_signal_pending(current)) { rc = -EINTR; @@ -141,7 +141,7 @@ int ecryptfs_write(struct inode *ecryptf num_bytes = total_remaining_bytes; if (pos < offset) { /* remaining zeros to write, up to destination offset */ - size_t total_remaining_zeros = (offset - pos); + loff_t total_remaining_zeros = (offset - pos); if (num_bytes > total_remaining_zeros) num_bytes = total_remaining_zeros;