From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 09FF2C432C0 for ; Fri, 22 Nov 2019 06:10:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D7A1D2068F for ; Fri, 22 Nov 2019 06:10:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574403046; bh=kqpzJnTxRpyBYOpXv54CkIzJJid5vTn2KtSckSJ5ySM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0cF5wR1tEUQaC95TN+tO79Mn9JkjLyVroIc172g0O0yhPdMIYj/eJJZut3eV5U7St H/Jc4wNV3M+o+s07vf0AFZ6VJdGEOTEiU9FjcmDre9LG88kl2tDe+n75q7Asz5P8B5 xTx2OSYk/YJQCMdrxd3l8gH6i7JdvAwiv9aCVbL4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727912AbfKVGKp (ORCPT ); Fri, 22 Nov 2019 01:10:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:34542 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729235AbfKVF4o (ORCPT ); Fri, 22 Nov 2019 00:56:44 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C731020717; Fri, 22 Nov 2019 05:56:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574402203; bh=kqpzJnTxRpyBYOpXv54CkIzJJid5vTn2KtSckSJ5ySM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BfWndtXbE7g4b9bTBIx3U2cVoDNBLmYiPPGFn8mH9fHgCn+uEayVeKgrzFnvK/6IQ YGq8t+nd9/I/R1J1DvplSpodb1NcuK8sPfuww4COsAH9E862NM0hJLjY3djXJNRQMW FdnDH9uHzsZhS/v1A2tajweBO7VhGtY8iX76hUtA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Petr Machata , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 052/127] vxlan: Fix error path in __vxlan_dev_create() Date: Fri, 22 Nov 2019 00:54:30 -0500 Message-Id: <20191122055544.3299-51-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191122055544.3299-1-sashal@kernel.org> References: <20191122055544.3299-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Petr Machata [ Upstream commit 6db9246871394b3a136cd52001a0763676563840 ] When a failure occurs in rtnl_configure_link(), the current code calls unregister_netdevice() to roll back the earlier call to register_netdevice(), and jumps to errout, which calls vxlan_fdb_destroy(). However unregister_netdevice() calls transitively ndo_uninit, which is vxlan_uninit(), and that already takes care of deleting the default FDB entry by calling vxlan_fdb_delete_default(). Since the entry added earlier in __vxlan_dev_create() is exactly the default entry, the cleanup code in the errout block always leads to double free and thus a panic. Besides, since vxlan_fdb_delete_default() always destroys the FDB entry with notification enabled, the deletion of the default entry is notified even before the addition was notified. Instead, move the unregister_netdevice() call after the manual destroy, which solves both problems. Fixes: 0241b836732f ("vxlan: fix default fdb entry netlink notify ordering during netdev create") Signed-off-by: Petr Machata Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/vxlan.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 6d26bbd190dd6..153a81ece9fe4 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -3217,6 +3217,7 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev, struct vxlan_net *vn = net_generic(net, vxlan_net_id); struct vxlan_dev *vxlan = netdev_priv(dev); struct vxlan_fdb *f = NULL; + bool unregister = false; int err; err = vxlan_dev_configure(net, dev, conf, false, extack); @@ -3242,12 +3243,11 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev, err = register_netdevice(dev); if (err) goto errout; + unregister = true; err = rtnl_configure_link(dev, NULL); - if (err) { - unregister_netdevice(dev); + if (err) goto errout; - } /* notify default fdb entry */ if (f) @@ -3255,9 +3255,16 @@ static int __vxlan_dev_create(struct net *net, struct net_device *dev, list_add(&vxlan->next, &vn->vxlan_list); return 0; + errout: + /* unregister_netdevice() destroys the default FDB entry with deletion + * notification. But the addition notification was not sent yet, so + * destroy the entry by hand here. + */ if (f) vxlan_fdb_destroy(vxlan, f, false); + if (unregister) + unregister_netdevice(dev); return err; } -- 2.20.1