From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:44182 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1164416AbeE1Kzi (ORCPT ); Mon, 28 May 2018 06:55:38 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jamal Hadi Salim , Davide Caratti , "David S. Miller" , Sasha Levin Subject: [PATCH 4.14 284/496] net/sched: fix idr leak in the error path of tcf_skbmod_init() Date: Mon, 28 May 2018 12:01:09 +0200 Message-Id: <20180528100331.808800023@linuxfoundation.org> In-Reply-To: <20180528100319.498712256@linuxfoundation.org> References: <20180528100319.498712256@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Davide Caratti [ Upstream commit f29cdfbe33d6915ba8056179b0041279a67e3647 ] tcf_skbmod_init() can fail after the idr has been successfully reserved. When this happens, every subsequent attempt to configure skbmod rules using the same idr value will systematically fail with -ENOSPC, unless the first attempt was done using the 'replace' keyword: # tc action add action skbmod swap mac index 100 RTNETLINK answers: Cannot allocate memory We have an error talking to the kernel # tc action add action skbmod swap mac index 100 RTNETLINK answers: No space left on device We have an error talking to the kernel # tc action add action skbmod swap mac index 100 RTNETLINK answers: No space left on device We have an error talking to the kernel ... Fix this in tcf_skbmod_init(), ensuring that tcf_idr_release() is called on the error path when the idr has been reserved, but not yet inserted. Also, don't test 'ovr' in the error path, to avoid a 'replace' failure implicitly become a 'delete' that leaks refcount in act_skbmod module: # rmmod act_skbmod; modprobe act_skbmod # tc action add action skbmod swap mac index 100 # tc action add action skbmod swap mac continue index 100 RTNETLINK answers: File exists We have an error talking to the kernel # tc action replace action skbmod swap mac continue index 100 RTNETLINK answers: Cannot allocate memory We have an error talking to the kernel # tc action list action skbmod # # rmmod act_skbmod rmmod: ERROR: Module act_skbmod is in use Fixes: 65a206c01e8e ("net/sched: Change act_api and act_xxx modules to use IDR") Acked-by: Jamal Hadi Salim Signed-off-by: Davide Caratti Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/sched/act_skbmod.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/sched/act_skbmod.c +++ b/net/sched/act_skbmod.c @@ -155,7 +155,7 @@ static int tcf_skbmod_init(struct net *n ASSERT_RTNL(); p = kzalloc(sizeof(struct tcf_skbmod_params), GFP_KERNEL); if (unlikely(!p)) { - if (ovr) + if (ret == ACT_P_CREATED) tcf_idr_release(*a, bind); return -ENOMEM; }