From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krishna Kumar Subject: [RFC] [PATCH] ipv6: Fix potential hang in mif6_add Date: Wed, 02 May 2012 11:39:57 +0530 Message-ID: <20120502060957.30368.34595.sendpatchset@localhost.localdomain> Cc: netdev@vger.kernel.org, Krishna Kumar To: davem@davemloft.net Return-path: Received: from e23smtp03.au.ibm.com ([202.81.31.145]:33798 "EHLO e23smtp03.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751503Ab2EBGKq (ORCPT ); Wed, 2 May 2012 02:10:46 -0400 Received: from /spool/local by e23smtp03.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 2 May 2012 06:01:01 +1000 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay03.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q426A0218192242 for ; Wed, 2 May 2012 16:10:00 +1000 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q426A0Xf000960 for ; Wed, 2 May 2012 16:10:00 +1000 Sender: netdev-owner@vger.kernel.org List-ID: Fix a potential "waiting for %s to become free" hang. mif6_add() called ip6mr_reg_vif to allocate/register a netdevice, which also took an extra reference on the device. On error, mif6_add should drop this reference before unregistering the device. (untested, noticed from code walkthrough) Signed-off-by: Krishna Kumar --- net/ipv6/ip6mr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -ruNp org/net/ipv6/ip6mr.c new/net/ipv6/ip6mr.c --- org/net/ipv6/ip6mr.c 2012-04-19 09:03:34.000000000 +0530 +++ new/net/ipv6/ip6mr.c 2012-05-02 10:51:01.953110994 +0530 @@ -937,8 +937,8 @@ static int mif6_add(struct net *net, str return -ENOBUFS; err = dev_set_allmulti(dev, 1); if (err) { - unregister_netdevice(dev); dev_put(dev); + unregister_netdevice(dev); return err; } break;