From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: [PATCH net-next] htb: fix sign extension bug Date: Thu, 1 Aug 2013 22:32:07 -0700 Message-ID: <20130801223207.2a9c69e9@nehalam.linuxnetplumber.net> References: <20130801211231.1b25c3be@nehalam.linuxnetplumber.net> <20130801221936.24d4b31e@nehalam.linuxnetplumber.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Cong Wang , netdev@vger.kernel.org To: David Miller Return-path: Received: from mail-pa0-f43.google.com ([209.85.220.43]:50967 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754694Ab3HBFcQ (ORCPT ); Fri, 2 Aug 2013 01:32:16 -0400 Received: by mail-pa0-f43.google.com with SMTP id hz10so272099pad.2 for ; Thu, 01 Aug 2013 22:32:15 -0700 (PDT) In-Reply-To: <20130801221936.24d4b31e@nehalam.linuxnetplumber.net> Sender: netdev-owner@vger.kernel.org List-ID: When userspace passes a large priority value the assignment of the unsigned value hopt->prio to signed int cl->prio causes cl->prio to become negative and the comparison is with TC_HTB_NUMPRIO is always false. The result is that HTB crashes by referencing outside the array when processing packets. With this patch the large value wraps around like other values outside the normal range. See: https://bugzilla.kernel.org/show_bug.cgi?id=60669 Signed-off-by: Stephen Hemminger --- a/net/sched/sch_htb.c 2013-06-20 09:22:46.489542435 -0700 +++ b/net/sched/sch_htb.c 2013-08-01 22:12:43.736307055 -0700 @@ -100,7 +100,7 @@ struct htb_class { struct psched_ratecfg ceil; s64 buffer, cbuffer;/* token bucket depth/rate */ s64 mbuffer; /* max wait time */ - int prio; /* these two are used only by leaves... */ + u32 prio; /* these two are used only by leaves... */ int quantum; /* but stored for parent-to-leaf return */ struct tcf_proto *filter_list; /* class attached filters */