Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932255Ab2KVVZJ (ORCPT ); Thu, 22 Nov 2012 16:25:09 -0500 Received: from mail.kernel.org ([198.145.19.201]:49621 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755218Ab2KVSkn (ORCPT ); Thu, 22 Nov 2012 13:40:43 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Sage Weil , Alex Elder , Yehuda Sadeh Subject: [ 143/171] libceph: (re)initialize bio_iter on start of message receive Date: Wed, 21 Nov 2012 16:41:29 -0800 Message-Id: <20121122004047.699116048@linuxfoundation.org> X-Mailer: git-send-email 1.8.0.197.g5a90748 In-Reply-To: <20121122004033.298367941@linuxfoundation.org> References: <20121122004033.298367941@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2073 Lines: 72 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sage Weil (cherry picked from commit a4107026976f06c9a6ce8cc84a763564ee39d901) Previously, we were opportunistically initializing the bio_iter if it appeared to be uninitialized in the middle of the read path. The problem is that a sequence like: - start reading message - initialize bio_iter - read half a message - messenger fault, reconnect - restart reading message - ** bio_iter now non-NULL, not reinitialized ** - read past end of bio, crash Instead, initialize the bio_iter unconditionally when we allocate/claim the message for read. Signed-off-by: Sage Weil Reviewed-by: Alex Elder Reviewed-by: Yehuda Sadeh Signed-off-by: Greg Kroah-Hartman --- net/ceph/messenger.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -1872,6 +1872,11 @@ static int read_partial_message(struct c else con->in_msg_pos.page_pos = 0; con->in_msg_pos.data_pos = 0; + +#ifdef CONFIG_BLOCK + if (m->bio) + init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg); +#endif } /* front */ @@ -1888,10 +1893,6 @@ static int read_partial_message(struct c if (ret <= 0) return ret; } -#ifdef CONFIG_BLOCK - if (m->bio && !m->bio_iter) - init_bio_iter(m->bio, &m->bio_iter, &m->bio_seg); -#endif /* (page) data */ while (con->in_msg_pos.data_pos < data_len) { @@ -1902,7 +1903,7 @@ static int read_partial_message(struct c return ret; #ifdef CONFIG_BLOCK } else if (m->bio) { - + BUG_ON(!m->bio_iter); ret = read_partial_message_bio(con, &m->bio_iter, &m->bio_seg, data_len, do_datacrc); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/