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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F58BCCA47C for ; Tue, 7 Jun 2022 20:12:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357796AbiFGUMv (ORCPT ); Tue, 7 Jun 2022 16:12:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359208AbiFGUJj (ORCPT ); Tue, 7 Jun 2022 16:09:39 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 871E01C4F0F; Tue, 7 Jun 2022 11:27:07 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2291361252; Tue, 7 Jun 2022 18:27:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05E32C385A2; Tue, 7 Jun 2022 18:27:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654626426; bh=r4Cxs6mC/j3Ia4H5h56qzcI8TWV9ryZCS5RxCwnAKOw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gON4QeA1WcKS7igaQ4w3hV1G4O2ABIk/Q/xXA1KSWV5TRmaie3a1/qwo8Jj4R0X+S puu/2a0QVYKCrpDd0RWJAZaTnCrXGJ+fnW40/qkvohv/bx/w0zzJvvQ2DfQoUbkfs0 m1+l4m2r2NguI632K2LEyUp2Iqf7darbgYssxzRQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ben Greear , Felix Fietkau , Sasha Levin Subject: [PATCH 5.17 373/772] mt76: fix tx status related use-after-free race on station removal Date: Tue, 7 Jun 2022 18:59:25 +0200 Message-Id: <20220607165000.006614205@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607164948.980838585@linuxfoundation.org> References: <20220607164948.980838585@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Felix Fietkau [ Upstream commit fcfe1b5e162bf473c1d47760962cec8523c00466 ] There is a small race window where ongoing tx activity can lead to a skb getting added to the status tracking idr after that idr has already been cleaned up, which will keep the wcid linked in the status poll list. Fix this by only adding status skbs if the wcid pointer is still assigned in dev->wcid, which gets cleared early by mt76_sta_pre_rcu_remove Fixes: bd1e3e7b693c ("mt76: introduce packet_id idr") Tested-by: Ben Greear Signed-off-by: Felix Fietkau Signed-off-by: Sasha Levin --- drivers/net/wireless/mediatek/mt76/mac80211.c | 2 ++ drivers/net/wireless/mediatek/mt76/tx.c | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/mediatek/mt76/mac80211.c b/drivers/net/wireless/mediatek/mt76/mac80211.c index 6023ff6dc059..cbda0f57ff9a 100644 --- a/drivers/net/wireless/mediatek/mt76/mac80211.c +++ b/drivers/net/wireless/mediatek/mt76/mac80211.c @@ -1344,7 +1344,9 @@ void mt76_sta_pre_rcu_remove(struct ieee80211_hw *hw, struct ieee80211_vif *vif, struct mt76_wcid *wcid = (struct mt76_wcid *)sta->drv_priv; mutex_lock(&dev->mutex); + spin_lock_bh(&dev->status_lock); rcu_assign_pointer(dev->wcid[wcid->idx], NULL); + spin_unlock_bh(&dev->status_lock); mutex_unlock(&dev->mutex); } EXPORT_SYMBOL_GPL(mt76_sta_pre_rcu_remove); diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wireless/mediatek/mt76/tx.c index 6b8c9dc80542..ccaf9a31fbc4 100644 --- a/drivers/net/wireless/mediatek/mt76/tx.c +++ b/drivers/net/wireless/mediatek/mt76/tx.c @@ -120,7 +120,7 @@ mt76_tx_status_skb_add(struct mt76_dev *dev, struct mt76_wcid *wcid, memset(cb, 0, sizeof(*cb)); - if (!wcid) + if (!wcid || !rcu_access_pointer(dev->wcid[wcid->idx])) return MT_PACKET_ID_NO_ACK; if (info->flags & IEEE80211_TX_CTL_NO_ACK) -- 2.35.1