From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755931Ab2GEIdM (ORCPT ); Thu, 5 Jul 2012 04:33:12 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:14259 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754507Ab2GEIdI (ORCPT ); Thu, 5 Jul 2012 04:33:08 -0400 X-IronPort-AV: E=Sophos;i="4.77,530,1336320000"; d="scan'208";a="5334298" From: Gao feng To: davem@davemloft.net Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, nhorman@tuxdriver.com, tj@kernel.org, lizefan@huawei.com, Gao feng Subject: [PATCH] cgroup: fix panic in netprio_cgroup Date: Thu, 5 Jul 2012 16:31:42 +0800 Message-Id: <1341477102-16988-1-git-send-email-gaofeng@cn.fujitsu.com> X-Mailer: git-send-email 1.7.7.6 X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/07/05 16:33:06, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/07/05 16:33:08, Serialize complete at 2012/07/05 16:33:08 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org we set max_prioidx to the first zero bit index of prioidx_map in function get_prioidx. So when we delete the low index netprio cgroup and adding a new netprio cgroup again,the max_prioidx will be set to the low index. when we set the high index cgroup's net_prio.ifpriomap,the function write_priomap will call update_netdev_tables to alloc memory which size is sizeof(struct netprio_map) + sizeof(u32) * (max_prioidx + 1), so the size of array that map->priomap point to is max_prioidx +1, which is low than what we actually need. fix this by adding check in get_prioidx,only set max_prioidx when max_prioidx low than the new prioidx. Signed-off-by: Gao feng --- net/core/netprio_cgroup.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c index 5b8aa2f..586f7d9 100644 --- a/net/core/netprio_cgroup.c +++ b/net/core/netprio_cgroup.c @@ -50,7 +50,8 @@ static int get_prioidx(u32 *prio) } set_bit(prioidx, prioidx_map); spin_unlock_irqrestore(&prioidx_map_lock, flags); - atomic_set(&max_prioidx, prioidx); + if (atomic_read(&max_prioidx) < prioidx) + atomic_set(&max_prioidx, prioidx); *prio = prioidx; return 0; } -- 1.7.7.6