From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 97D13386441; Wed, 23 Sep 2026 14:39:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790174399; cv=none; b=MX8cQ/UTSlLk2a0dpSXfI8j0hne2SGn3c8fsxC651I0oIPofHRqsRrAvJNsjRjj6FIO8iUo+frQBCt6DDO2n9ZaaC86H0ouzrlcPA5szpga7ypKHqUAaZgvAjhZkBVdfaeq+2vTocWUvaS97fHFiwWdMUVnGCtv5poG0OAhjb2o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790174399; c=relaxed/simple; bh=LDgLLm2A7XjS972H+fP+8b0Npe3ZwiQ2FxLY6DjCnL8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=g4EauphKANp6fIjRLJNmMDqr0yPmSMUlCscTkHhyM46aocay0O3u4kDTBx0f89lnA2mcjc9Buhv63njGW6J722hKuCUFk8vk9VPVaVigwHzwQsie5zY2wCj8sTOwTkaRxrIXpqJPbIoncoIypZ6Tp8I2ru7DppUfxZIKvx9/sps= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PC6WAbkT; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="PC6WAbkT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F251F1F000FF; Wed, 23 Sep 2026 14:39:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790174398; bh=8TMYlmS91MjbWtXlo6Z+QLnE3dK97X+oPsXvD+dWblQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PC6WAbkT82t47Rl72c9w1BvR7bmrpU3Sy1eS5Ym/hXESdYlEbtVP8tBfVFqJ88w9j /LRu7JHgJWRbdRo7TbirVUPQ4yIUlpXtPFD7g/r2BprqFJo8K8GBMlfzZLmHjtRrcQ YbDIk92NgFknEO/2fJjed8ekhWyQLCKHJ+hbiz+g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Johannes Berg , Sasha Levin Subject: [PATCH 6.18 070/398] wifi: mac80211: unlist vifs when their netdev is unregistered Date: Wed, 23 Sep 2026 16:02:24 +0200 Message-ID: <20260923140645.248282868@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg [ Upstream commit eee2efd82867b623982ac51925b5a1812a74c50d ] mac80211 only removes vifs from the local->interfaces list when an interface is removed via ieee80211_if_remove(), before it unregisters the netdev. However, it's possible for a netdev to be unregistered without going through that: When the netns that holds the wiphy is destroyed, the wiphy is supposed to move to the init_ns, but that can run into allocation failures. Then, mac80211 has an interface listed that doesn't exist, and will eventually hit BUG: failure at net/wireless/core.h:141/wiphy_to_rdev()! ... _cfg80211_unregister_wdev+0x24/0x36a [cfg80211] cfg80211_unregister_wdev+0x15/0x1d [cfg80211] ieee80211_remove_interfaces+0x1ff/0x257 [mac80211] ieee80211_unregister_hw+0x73/0x1d1 [mac80211] mac80211_hwsim_del_radio+0x114/0x166 [mac80211_hwsim] Remove the interface from the list in ->ndo_uninit if it's still around to avoid this. Assisted-by: LLM Fixes: 463d018323851 ("cfg80211: make aware of net namespaces") Link: https://patch.msgid.link/20260904170220.038ad73e6c04.I990abca78483e058746b6f42b4796717c3028164@changeid Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- net/mac80211/iface.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 82eff9e867c1f..3da26d4d75fc3 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -885,9 +885,33 @@ static void ieee80211_teardown_sdata(struct ieee80211_sub_if_data *sdata) ieee80211_link_stop(&sdata->deflink); } +/* + * The netdev can be unregistered without mac80211 doing it, e.g. by the netdev + * core when cfg80211 couldn't move it out of a network namespace that's being + * destroyed. Drop it from the interface list either way. + */ +static void ieee80211_unlist_sdata(struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_local *local = sdata->local; + struct ieee80211_sub_if_data *iter; + + ASSERT_RTNL(); + + list_for_each_entry(iter, &local->interfaces, list) { + if (iter != sdata) + continue; + guard(mutex)(&local->iflist_mtx); + list_del_rcu(&sdata->list); + return; + } +} + static void ieee80211_uninit(struct net_device *dev) { - ieee80211_teardown_sdata(IEEE80211_DEV_TO_SUB_IF(dev)); + struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); + + ieee80211_unlist_sdata(sdata); + ieee80211_teardown_sdata(sdata); } static int ieee80211_netdev_setup_tc(struct net_device *dev, -- 2.53.0