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=-13.6 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=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 3AC36C43387 for ; Tue, 8 Jan 2019 19:59:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A9DB20660 for ; Tue, 8 Jan 2019 19:59:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546977555; bh=ut/ZKF3iyuvn9FFdCEt+kJWQ6RFeWjzeCWezC/N+LNo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mLuRmZhOM9CjllsAyTz18Iprgomf3HvlU/1bGh+6cKt0Am2yVyxVAm44O9Pbfwqa5 ff2rUR5TtVbbl/5fNy1GZiOA2DeTaZB1Sw0WNMFgFAX71zhPOSEb23p/vccUIRHno/ CmRAIkkLZCLOTX89ZqnjAsdlkYi0otbhguoMuek0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731135AbfAHT7I (ORCPT ); Tue, 8 Jan 2019 14:59:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:36790 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730372AbfAHT3Y (ORCPT ); Tue, 8 Jan 2019 14:29:24 -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 97D5020883; Tue, 8 Jan 2019 19:29:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546975763; bh=ut/ZKF3iyuvn9FFdCEt+kJWQ6RFeWjzeCWezC/N+LNo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Cg5GwEIkgXyEZGPOlJHQ308OTV/zveprMIyVQiCJLufwWlzE6va6p+yT8+h1El6wf GPJosHQy+doDOMfkn8oTFuHoD0mvYVnZazxyD5XGp04tGk3zAzwf971nnjgeQC9EzV Z9w0r9/l/gLPUVEERixRZLEl5Ah4uUzfZsrWkf1E= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zhi Chen , Kalle Valo , Sasha Levin , ath10k@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.20 105/117] ath10k: fix peer stats null pointer dereference Date: Tue, 8 Jan 2019 14:26:13 -0500 Message-Id: <20190108192628.121270-105-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190108192628.121270-1-sashal@kernel.org> References: <20190108192628.121270-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Zhi Chen [ Upstream commit 2d3b55853b123c177037cf534c5aaa2650310094 ] There was a race condition in SMP that an ath10k_peer was created but its member sta was null. Following are procedures of ath10k_peer creation and member sta access in peer statistics path. 1. Peer creation: ath10k_peer_create() =>ath10k_wmi_peer_create() =>ath10k_wait_for_peer_created() ... # another kernel path, RX from firmware ath10k_htt_t2h_msg_handler() =>ath10k_peer_map_event() =>wake_up() # ar->peer_map[id] = peer //add peer to map #wake up original path from waiting ... # peer->sta = sta //sta assignment 2. RX path of statistics ath10k_htt_t2h_msg_handler() =>ath10k_update_per_peer_tx_stats() =>ath10k_htt_fetch_peer_stats() # peer->sta //sta accessing Any access of peer->sta after peer was added to peer_map but before sta was assigned could cause a null pointer issue. And because these two steps are asynchronous, no proper lock can protect them. So both peer and sta need to be checked before access. Tested: QCA9984 with firmware ver 10.4-3.9.0.1-00005 Signed-off-by: Zhi Chen Signed-off-by: Kalle Valo Signed-off-by: Sasha Levin --- drivers/net/wireless/ath/ath10k/debugfs_sta.c | 2 +- drivers/net/wireless/ath/ath10k/htt_rx.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/ath/ath10k/debugfs_sta.c b/drivers/net/wireless/ath/ath10k/debugfs_sta.c index b09cdc699c69..38afbbd9fb44 100644 --- a/drivers/net/wireless/ath/ath10k/debugfs_sta.c +++ b/drivers/net/wireless/ath/ath10k/debugfs_sta.c @@ -71,7 +71,7 @@ void ath10k_sta_update_rx_tid_stats_ampdu(struct ath10k *ar, u16 peer_id, u8 tid spin_lock_bh(&ar->data_lock); peer = ath10k_peer_find_by_id(ar, peer_id); - if (!peer) + if (!peer || !peer->sta) goto out; arsta = (struct ath10k_sta *)peer->sta->drv_priv; diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c index ffec98f7be50..2c2761d04d01 100644 --- a/drivers/net/wireless/ath/ath10k/htt_rx.c +++ b/drivers/net/wireless/ath/ath10k/htt_rx.c @@ -2832,7 +2832,7 @@ static void ath10k_htt_fetch_peer_stats(struct ath10k *ar, rcu_read_lock(); spin_lock_bh(&ar->data_lock); peer = ath10k_peer_find_by_id(ar, peer_id); - if (!peer) { + if (!peer || !peer->sta) { ath10k_warn(ar, "Invalid peer id %d peer stats buffer\n", peer_id); goto out; @@ -2885,7 +2885,7 @@ static void ath10k_fetch_10_2_tx_stats(struct ath10k *ar, u8 *data) rcu_read_lock(); spin_lock_bh(&ar->data_lock); peer = ath10k_peer_find_by_id(ar, peer_id); - if (!peer) { + if (!peer || !peer->sta) { ath10k_warn(ar, "Invalid peer id %d in peer stats buffer\n", peer_id); goto out; -- 2.19.1