From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758269AbaIOUoh (ORCPT ); Mon, 15 Sep 2014 16:44:37 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:55096 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754731AbaIOTgs (ORCPT ); Mon, 15 Sep 2014 15:36:48 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ilya Dryomov , Sage Weil , Alex Elder Subject: [PATCH 3.16 137/158] libceph: set last_piece in ceph_msg_data_pages_cursor_init() correctly Date: Mon, 15 Sep 2014 12:26:16 -0700 Message-Id: <20140915192546.985023487@linuxfoundation.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <20140915192542.872134685@linuxfoundation.org> References: <20140915192542.872134685@linuxfoundation.org> User-Agent: quilt/0.63-1 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 3.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ilya Dryomov commit 5f740d7e1531099b888410e6bab13f68da9b1a4d upstream. Determining ->last_piece based on the value of ->page_offset + length is incorrect because length here is the length of the entire message. ->last_piece set to false even if page array data item length is <= PAGE_SIZE, which results in invalid length passed to ceph_tcp_{send,recv}page() and causes various asserts to fire. # cat pages-cursor-init.sh #!/bin/bash rbd create --size 10 --image-format 2 foo FOO_DEV=$(rbd map foo) dd if=/dev/urandom of=$FOO_DEV bs=1M &>/dev/null rbd snap create foo@snap rbd snap protect foo@snap rbd clone foo@snap bar # rbd_resize calls librbd rbd_resize(), size is in bytes ./rbd_resize bar $(((4 << 20) + 512)) rbd resize --size 10 bar BAR_DEV=$(rbd map bar) # trigger a 512-byte copyup -- 512-byte page array data item dd if=/dev/urandom of=$BAR_DEV bs=1M count=1 seek=5 The problem exists only in ceph_msg_data_pages_cursor_init(), ceph_msg_data_pages_advance() does the right thing. The size_t cast is unnecessary. Signed-off-by: Ilya Dryomov Reviewed-by: Sage Weil Reviewed-by: Alex Elder Signed-off-by: Greg Kroah-Hartman --- net/ceph/messenger.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -900,7 +900,7 @@ static void ceph_msg_data_pages_cursor_i BUG_ON(page_count > (int)USHRT_MAX); cursor->page_count = (unsigned short)page_count; BUG_ON(length > SIZE_MAX - cursor->page_offset); - cursor->last_piece = (size_t)cursor->page_offset + length <= PAGE_SIZE; + cursor->last_piece = cursor->page_offset + cursor->resid <= PAGE_SIZE; } static struct page *