From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4BF5825D8F9; Tue, 11 Mar 2025 15:14:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741706044; cv=none; b=ZYf7qGCmBh5dAgSCfKZBD6HZjP9gz/hyxBEf5w4GSjA0ViNWvXerYWQKpRHIp1KFheb+joJ8erxD73zTV6uOYkf0XFrNLcjZhwL077N4wvBpw82k/LAT8aljDgfHQdwXiKyMHOAkjHDSsHilxkfDNMowspI1DnuGipRuYVgDLhs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741706044; c=relaxed/simple; bh=EZ6dvufOJZQ8DdjjLmMTnWyWTPUFyJu3A1LJJe0oFZ8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sRAwNPCfP/oUoe+bXBWVZ7t8bzOz+jyz5Dz8ckDjv1jTizhHjGCVYQrx7jZ50co8bKQwEtgYpHMyr4HgfW8tl/CQAbEDWU4MumugeApAZZC+2kRWfvt5rTRRNT+dFjRKXWmK5QXHIJsqphX9jkt6w7na1uod+McE88Jre3oi9dk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JuqD8zvW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JuqD8zvW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C263CC4CEE9; Tue, 11 Mar 2025 15:14:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741706044; bh=EZ6dvufOJZQ8DdjjLmMTnWyWTPUFyJu3A1LJJe0oFZ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JuqD8zvW5UJp4gmXlhzjKyOMO9FeL6vo0FvzQBcMzq/qsJAuyTE/hb7zlgfVJEDcv MF1KHhFLgQL4LdtpmEipSw8bTEocLY34aujJd1lX63MO60CMshQAG4Fo225p8/fLtq vvcwqKmRfes3dbcor2RA11g5/0fhf17UGCuHtiVU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shuang Li , Xin Long , "David S. Miller" , Olivier Matz , Ivan Delalande Subject: [PATCH 5.4 225/328] vlan: move dev_put into vlan_dev_uninit Date: Tue, 11 Mar 2025 15:59:55 +0100 Message-ID: <20250311145723.855037451@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250311145714.865727435@linuxfoundation.org> References: <20250311145714.865727435@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long commit d6ff94afd90b0ce8d1715f8ef77d4347d7a7f2c0 upstream. Shuang Li reported an QinQ issue by simply doing: # ip link add dummy0 type dummy # ip link add link dummy0 name dummy0.1 type vlan id 1 # ip link add link dummy0.1 name dummy0.1.2 type vlan id 2 # rmmod 8021q unregister_netdevice: waiting for dummy0.1 to become free. Usage count = 1 When rmmods 8021q, all vlan devs are deleted from their real_dev's vlan grp and added into list_kill by unregister_vlan_dev(). dummy0.1 is unregistered before dummy0.1.2, as it's using for_each_netdev() in __rtnl_kill_links(). When unregisters dummy0.1, dummy0.1.2 is not unregistered in the event of NETDEV_UNREGISTER, as it's been deleted from dummy0.1's vlan grp. However, due to dummy0.1.2 still holding dummy0.1, dummy0.1 will keep waiting in netdev_wait_allrefs(), while dummy0.1.2 will never get unregistered and release dummy0.1, as it delays dev_put until calling dev->priv_destructor, vlan_dev_free(). This issue was introduced by Commit 563bcbae3ba2 ("net: vlan: fix a UAF in vlan_dev_real_dev()"), and this patch is to fix it by moving dev_put() into vlan_dev_uninit(), which is called after NETDEV_UNREGISTER event but before netdev_wait_allrefs(). Fixes: 563bcbae3ba2 ("net: vlan: fix a UAF in vlan_dev_real_dev()") Reported-by: Shuang Li Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Olivier Matz Signed-off-by: Ivan Delalande Signed-off-by: Greg Kroah-Hartman --- net/8021q/vlan_dev.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -606,7 +606,12 @@ void vlan_dev_free_egress_priority(const static void vlan_dev_uninit(struct net_device *dev) { + struct vlan_dev_priv *vlan = vlan_dev_priv(dev); + vlan_dev_free_egress_priority(dev); + + /* Get rid of the vlan's reference to real_dev */ + dev_put(vlan->real_dev); } static netdev_features_t vlan_dev_fix_features(struct net_device *dev, @@ -798,9 +803,6 @@ static void vlan_dev_free(struct net_dev free_percpu(vlan->vlan_pcpu_stats); vlan->vlan_pcpu_stats = NULL; - - /* Get rid of the vlan's reference to real_dev */ - dev_put(vlan->real_dev); } void vlan_setup(struct net_device *dev)