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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 2D085C282C5 for ; Thu, 24 Jan 2019 19:37:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EBD5221908 for ; Thu, 24 Jan 2019 19:37:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548358679; bh=jTw6x7NZ1T7rD576reZdJ4B7JzRYGWGNMO/R5TGNqEU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Y6DoI1yctOj2MJ9piTvTuF0T+HZt1hQ7k8jrC3QJgrj+6fRmV1oJRiu/Yv1b+SODp JeQtsZNziTGgBECNxoeq2Dz25RL6vPy2P0idbC0fxwcUkCMWsep6aEszJMCM2F+Dne BDKe2z3xa432qs+bsGCdiVoBNM1NaTQQupj6+BmA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731583AbfAXTh5 (ORCPT ); Thu, 24 Jan 2019 14:37:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:37996 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732714AbfAXTh4 (ORCPT ); Thu, 24 Jan 2019 14:37:56 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3803B218FC; Thu, 24 Jan 2019 19:37:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548358675; bh=jTw6x7NZ1T7rD576reZdJ4B7JzRYGWGNMO/R5TGNqEU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P6dYPM+3y0QmMq4lpK3jWfIv5ZMJDCftvrBedNhX9X0F6yaq9TeYrCoZtKws9nCMG Nuok8a+kZVM8jbFxN2PZUZ+sRQhjMjocQKXwkKizN/6uoeTK0m43O14bF/cW9cxfYC IP27wvA16rfEwQxY2rvWlcHJvkN/A4iFPgirznvc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhi Chen , Kalle Valo , Sasha Levin Subject: [PATCH 4.19 091/106] ath10k: fix peer stats null pointer dereference Date: Thu, 24 Jan 2019 20:20:48 +0100 Message-Id: <20190124190211.826697777@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190124190206.342411005@linuxfoundation.org> References: <20190124190206.342411005@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ 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 a63c97e2c50c..6f10331e986b 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 4d1cd90d6d27..03d4cc6f35bc 100644 --- a/drivers/net/wireless/ath/ath10k/htt_rx.c +++ b/drivers/net/wireless/ath/ath10k/htt_rx.c @@ -2589,7 +2589,7 @@ 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; @@ -2642,7 +2642,7 @@ 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