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 43C8379F2; Tue, 5 Dec 2023 03:41:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="P8mj8QtU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CEF0EC433C7; Tue, 5 Dec 2023 03:41:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1701747673; bh=Jd8pz4VSHjIewZv9Gha4slNuXD1WFx5XVcCIaJ+U3vw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P8mj8QtU2tLbJTJkkMAF971Klt5APp9N2TojGZkCT0eTKpBJzoOo/cG0/BsgDMhol 0LTHSaIougQE141Dct8Dls2nGV32IYIt6sakhnGkI8MZ9baR6AjbZljoIUdfHmBCm/ C7W/smNrdj134gP7nI322nVsO1801qNGyPgCDs1g= 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 Subject: [PATCH 5.15 26/67] vlan: move dev_put into vlan_dev_uninit Date: Tue, 5 Dec 2023 12:17:11 +0900 Message-ID: <20231205031521.311405664@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231205031519.853779502@linuxfoundation.org> References: <20231205031519.853779502@linuxfoundation.org> User-Agent: quilt/0.67 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 5.15-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: 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 @@ -638,7 +638,12 @@ 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, @@ -851,9 +856,6 @@ 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)