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=-9.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 0B95CC04EBD for ; Tue, 16 Oct 2018 04:12:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C855D2145D for ; Tue, 16 Oct 2018 04:12:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Nx0m/PD6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C855D2145D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727948AbeJPMBK (ORCPT ); Tue, 16 Oct 2018 08:01:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:47972 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727858AbeJPMBJ (ORCPT ); Tue, 16 Oct 2018 08:01:09 -0400 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 EE4342145D; Tue, 16 Oct 2018 04:12:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539663167; bh=QVoFIwyHcjvVWOSMrzErhKNN8Z6L0WQbnkU/3FNVh2k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nx0m/PD6iuU6VMQfxWqRlIQFSnKgHvMlmi+jPXRyYlY9eQunGgCp088ZMvvvBng5R Pzb1+IWJwKsWm2239R1AW5CNm5seONOdATA6ERuRIeOcb4r3NjWAkd6S3mXMe12hme VKqCWzwHZnntC9xorecgXQSmNKL9ABW3ijhrJD0Q= From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Martin Willi , Johannes Berg , Sasha Levin Subject: [PATCH AUTOSEL 4.18 025/100] mac80211_hwsim: fix locking when iterating radios during ns exit Date: Tue, 16 Oct 2018 00:11:06 -0400 Message-Id: <20181016041221.135528-25-sashal@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181016041221.135528-1-sashal@kernel.org> References: <20181016041221.135528-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Martin Willi [ Upstream commit 628980e5c8f038f730582c6ee50b7410741cd96e ] The cleanup of radios during namespace exit has recently been reworked to directly delete a radio while temporarily releasing the spinlock, fixing a race condition between the work-queue execution and namespace exits. However, the temporary unlock allows unsafe modifications on the iterated list, resulting in a potential crash when continuing the iteration of additional radios. Move radios about to destroy to a temporary list, and clean that up after releasing the spinlock once iteration is complete. Fixes: 8cfd36a0b53a ("mac80211_hwsim: fix use-after-free bug in hwsim_exit_net") Signed-off-by: Martin Willi Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- drivers/net/wireless/mac80211_hwsim.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 80e2c8595c7c..6b90bef58293 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -3523,6 +3523,7 @@ static __net_init int hwsim_init_net(struct net *net) static void __net_exit hwsim_exit_net(struct net *net) { struct mac80211_hwsim_data *data, *tmp; + LIST_HEAD(list); spin_lock_bh(&hwsim_radio_lock); list_for_each_entry_safe(data, tmp, &hwsim_radios, list) { @@ -3533,17 +3534,19 @@ static void __net_exit hwsim_exit_net(struct net *net) if (data->netgroup == hwsim_net_get_netgroup(&init_net)) continue; - list_del(&data->list); + list_move(&data->list, &list); rhashtable_remove_fast(&hwsim_radios_rht, &data->rht, hwsim_rht_params); hwsim_radios_generation++; - spin_unlock_bh(&hwsim_radio_lock); + } + spin_unlock_bh(&hwsim_radio_lock); + + list_for_each_entry_safe(data, tmp, &list, list) { + list_del(&data->list); mac80211_hwsim_del_radio(data, wiphy_name(data->hw->wiphy), NULL); - spin_lock_bh(&hwsim_radio_lock); } - spin_unlock_bh(&hwsim_radio_lock); ida_simple_remove(&hwsim_netgroup_ida, hwsim_net_get_netgroup(net)); } -- 2.17.1