From patchwork Mon Jun 17 17:30:06 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 251936 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 699222C01FC for ; Tue, 18 Jun 2013 03:31:59 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UodHR-0001z3-8K; Mon, 17 Jun 2013 17:31:49 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UodHI-0001x0-IG for kernel-team@lists.ubuntu.com; Mon, 17 Jun 2013 17:31:40 +0000 Received: from c-67-160-231-42.hsd1.ca.comcast.net ([67.160.231.42] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UodHH-0007CM-Lz; Mon, 17 Jun 2013 17:31:40 +0000 Received: from kamal by fourier with local (Exim 4.80) (envelope-from ) id 1UodHF-00063e-2d; Mon, 17 Jun 2013 10:31:37 -0700 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 02/84] mac80211: close AP_VLAN interfaces before unregistering all Date: Mon, 17 Jun 2013 10:30:06 -0700 Message-Id: <1371490288-23167-3-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1371490288-23167-1-git-send-email-kamal@canonical.com> References: <1371490288-23167-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Cc: Kamal Mostafa , Johannes Berg , Eric Dumazet X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.8.13.3 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg commit c8aa22db0112f640ac6631347f850879c621840b upstream. Since Eric's commit efe117ab8 ("Speedup ieee80211_remove_interfaces") there's a bug in mac80211 when it unregisters with AP_VLAN interfaces up. If the AP_VLAN interface was registered after the AP it belongs to (which is the typical case) and then we get into this code path, unregister_netdevice_many() will crash because it isn't prepared to deal with interfaces being closed in the middle of it. Exactly this happens though, because we iterate the list, find the AP master this AP_VLAN belongs to and dev_close() the dependent VLANs. After this, unregister_netdevice_many() won't pick up the fact that the AP_VLAN is already down and will do it again, causing a crash. Cc: Eric Dumazet Signed-off-by: Johannes Berg Signed-off-by: Kamal Mostafa --- net/mac80211/iface.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 8be854e..00bd646 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1657,6 +1657,15 @@ void ieee80211_remove_interfaces(struct ieee80211_local *local) ASSERT_RTNL(); + /* + * Close all AP_VLAN interfaces first, as otherwise they + * might be closed while the AP interface they belong to + * is closed, causing unregister_netdevice_many() to crash. + */ + list_for_each_entry(sdata, &local->interfaces, list) + if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) + dev_close(sdata->dev); + mutex_lock(&local->iflist_mtx); list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) { list_del(&sdata->list);