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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.19 05/43] net: vlan: avoid leaks on register_vlan_dev() failures
Date:   Fri, 15 Jan 2021 13:27:35 +0100
Message-Id: <20210115121957.312655457@linuxfoundation.org>
In-Reply-To: <20210115121957.037407908@linuxfoundation.org>
References: <20210115121957.037407908@linuxfoundation.org>
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From: Jakub Kicinski <kuba@kernel.org>

[ Upstream commit 55b7ab1178cbf41f979ff83236d3321ad35ed2ad ]

VLAN checks for NETREG_UNINITIALIZED to distinguish between
registration failure and unregistration in progress.

Since commit cb626bf566eb ("net-sysfs: Fix reference count leak")
registration failure may, however, result in NETREG_UNREGISTERED
as well as NETREG_UNINITIALIZED.

This fix is similer to cebb69754f37 ("rtnetlink: Fix
memory(net_device) leak when ->newlink fails")

Fixes: cb626bf566eb ("net-sysfs: Fix reference count leak")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/8021q/vlan.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -277,7 +277,8 @@ static int register_vlan_device(struct n
 	return 0;
 
 out_free_newdev:
-	if (new_dev->reg_state == NETREG_UNINITIALIZED)
+	if (new_dev->reg_state == NETREG_UNINITIALIZED ||
+	    new_dev->reg_state == NETREG_UNREGISTERED)
 		free_netdev(new_dev);
 	return err;
 }