From patchwork Fri Oct 9 11:58:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Berg X-Patchwork-Id: 268757 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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 6017AC433E7 for ; Fri, 9 Oct 2020 11:58:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 010262226B for ; Fri, 9 Oct 2020 11:58:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388260AbgJIL6e (ORCPT ); Fri, 9 Oct 2020 07:58:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732480AbgJIL6e (ORCPT ); Fri, 9 Oct 2020 07:58:34 -0400 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB02EC0613D2 for ; Fri, 9 Oct 2020 04:58:33 -0700 (PDT) Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94) (envelope-from ) id 1kQr2a-002FEh-Ra; Fri, 09 Oct 2020 13:58:28 +0200 From: Johannes Berg To: linux-wireless@vger.kernel.org Cc: Johannes Berg Subject: [PATCH] cfg80211: initialize wdev data earlier Date: Fri, 9 Oct 2020 13:58:22 +0200 Message-Id: <20201009135821.fdcbba3aad65.Ie9201d91dbcb7da32318812effdc1561aeaf4cdc@changeid> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Johannes Berg There's a race condition in the netdev registration in that NETDEV_REGISTER actually happens after the netdev is available, and so if we initialize things only there, we might get called with an uninitialized wdev through nl80211 - not using a wdev but using a netdev interface index. I found this while looking into a syzbot report, but it doesn't really seem to be related, and unfortunately there's no repro for it (yet). I can't (yet) explain how it managed to get into cfg80211_release_pmsr() from nl80211_netlink_notify() without the wdev having been initialized, as the latter only iterates the wdevs that are linked into the rdev, which even without the change here happened after init. However, looking at this, it seems fairly clear that the init needs to be done earlier, otherwise we might even re-init on a netns move, when data might still be pending. Signed-off-by: Johannes Berg --- net/wireless/core.c | 57 +++++++++++++++++++++++------------------- net/wireless/core.h | 5 ++-- net/wireless/nl80211.c | 3 ++- 3 files changed, 36 insertions(+), 29 deletions(-) diff --git a/net/wireless/core.c b/net/wireless/core.c index 354b0ccbdc24..e02549317126 100644 --- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -1248,8 +1248,7 @@ void cfg80211_stop_iface(struct wiphy *wiphy, struct wireless_dev *wdev, } EXPORT_SYMBOL(cfg80211_stop_iface); -void cfg80211_init_wdev(struct cfg80211_registered_device *rdev, - struct wireless_dev *wdev) +void cfg80211_init_wdev(struct wireless_dev *wdev) { mutex_init(&wdev->mtx); INIT_LIST_HEAD(&wdev->event_list); @@ -1260,6 +1259,30 @@ void cfg80211_init_wdev(struct cfg80211_registered_device *rdev, spin_lock_init(&wdev->pmsr_lock); INIT_WORK(&wdev->pmsr_free_wk, cfg80211_pmsr_free_wk); +#ifdef CONFIG_CFG80211_WEXT + wdev->wext.default_key = -1; + wdev->wext.default_mgmt_key = -1; + wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC; +#endif + + if (wdev->wiphy->flags & WIPHY_FLAG_PS_ON_BY_DEFAULT) + wdev->ps = true; + else + wdev->ps = false; + /* allow mac80211 to determine the timeout */ + wdev->ps_timeout = -1; + + if ((wdev->iftype == NL80211_IFTYPE_STATION || + wdev->iftype == NL80211_IFTYPE_P2P_CLIENT || + wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr) + wdev->netdev->priv_flags |= IFF_DONT_BRIDGE; + + INIT_WORK(&wdev->disconnect_wk, cfg80211_autodisconnect_wk); +} + +void cfg80211_register_wdev(struct cfg80211_registered_device *rdev, + struct wireless_dev *wdev) +{ /* * We get here also when the interface changes network namespaces, * as it's registered into the new one, but we don't want it to @@ -1293,6 +1316,11 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb, switch (state) { case NETDEV_POST_INIT: SET_NETDEV_DEVTYPE(dev, &wiphy_type); + wdev->netdev = dev; + /* can only change netns with wiphy */ + dev->features |= NETIF_F_NETNS_LOCAL; + + cfg80211_init_wdev(wdev); break; case NETDEV_REGISTER: /* @@ -1300,35 +1328,12 @@ static int cfg80211_netdev_notifier_call(struct notifier_block *nb, * called within code protected by it when interfaces * are added with nl80211. */ - /* can only change netns with wiphy */ - dev->features |= NETIF_F_NETNS_LOCAL; - if (sysfs_create_link(&dev->dev.kobj, &rdev->wiphy.dev.kobj, "phy80211")) { pr_err("failed to add phy80211 symlink to netdev!\n"); } - wdev->netdev = dev; -#ifdef CONFIG_CFG80211_WEXT - wdev->wext.default_key = -1; - wdev->wext.default_mgmt_key = -1; - wdev->wext.connect.auth_type = NL80211_AUTHTYPE_AUTOMATIC; -#endif - - if (wdev->wiphy->flags & WIPHY_FLAG_PS_ON_BY_DEFAULT) - wdev->ps = true; - else - wdev->ps = false; - /* allow mac80211 to determine the timeout */ - wdev->ps_timeout = -1; - - if ((wdev->iftype == NL80211_IFTYPE_STATION || - wdev->iftype == NL80211_IFTYPE_P2P_CLIENT || - wdev->iftype == NL80211_IFTYPE_ADHOC) && !wdev->use_4addr) - dev->priv_flags |= IFF_DONT_BRIDGE; - - INIT_WORK(&wdev->disconnect_wk, cfg80211_autodisconnect_wk); - cfg80211_init_wdev(rdev, wdev); + cfg80211_register_wdev(rdev, wdev); break; case NETDEV_GOING_DOWN: cfg80211_leave(rdev, wdev); diff --git a/net/wireless/core.h b/net/wireless/core.h index 67b0389fca4d..8cd4a9793298 100644 --- a/net/wireless/core.h +++ b/net/wireless/core.h @@ -208,8 +208,9 @@ struct wiphy *wiphy_idx_to_wiphy(int wiphy_idx); int cfg80211_switch_netns(struct cfg80211_registered_device *rdev, struct net *net); -void cfg80211_init_wdev(struct cfg80211_registered_device *rdev, - struct wireless_dev *wdev); +void cfg80211_init_wdev(struct wireless_dev *wdev); +void cfg80211_register_wdev(struct cfg80211_registered_device *rdev, + struct wireless_dev *wdev); static inline void wdev_lock(struct wireless_dev *wdev) __acquires(wdev) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 7fd45f6ddb05..863d414729e2 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -3798,7 +3798,8 @@ static int nl80211_new_interface(struct sk_buff *skb, struct genl_info *info) * P2P Device and NAN do not have a netdev, so don't go * through the netdev notifier and must be added here */ - cfg80211_init_wdev(rdev, wdev); + cfg80211_init_wdev(wdev); + cfg80211_register_wdev(rdev, wdev); break; default: break;