From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) (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 A45372EEE9E for ; Wed, 24 Jun 2026 03:05:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.61.82.184 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782270355; cv=none; b=pA73fsvb4QGzMVhaQuGeLQnO5+r4NSKBGAmsYOOGE3pgdpir+jg3yS9Nw2V3xD7WfbAknWhaivcgxxDIc6vuZJ1uE5ecP7Ah/daq4BIWEfMAg4thgZKEvSLuaWLjwb6JVW7PAN5BU3z+irv2dBxO5YueAsg6NgljHJ93uOf4noI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782270355; c=relaxed/simple; bh=yklzPpBnEGLl9MOs8d6uAhHYK0T1lxAMcDlCJtu5fUI=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=N0YFcUFPjzwcgchnBcmDNqQ3fok4kP2agkimgD3wfL/EQ8F2gjWfoiRgWE569E6YeSd0yPhqNEe68WBSU/IV5ZDhpORmUYFmSOBl881pkw/TmXIH5/LoysBn+QWulSQQ+bnY0l9h6Pd+9V2outP3souVSPMYm+HQVCVivg58MjQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com; spf=pass smtp.mailfrom=mediatek.com; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b=RMq5bKH7; arc=none smtp.client-ip=210.61.82.184 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mediatek.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="RMq5bKH7" X-UUID: 96919ea86f7911f18dc8c9802ae25ab1-20260624 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:CC:To:From; bh=2eZ75O7x3e8enqehiGd6zaRF5hMlFKzbSAUTfVWZPS0=; b=RMq5bKH73vlxy+mxM475ghj3XMcz1DuouaDwnWSmilw3Uq7OqChFA4d/t2//xxZxzuH0STAW/pJVhj7CEoYRV4CqTIje4/roJ2nF/4S5sC89Fzp3RSn/pCq3r1FbzrmcwtmLHwsYLBjA8r6VvkiR7tKknx7BgwD1DUukru2enhg=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.17,REQID:e8dedd6f-6d14-488a-a408-9f9393b9f487,IP:0,U RL:0,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTION: release,TS:0 X-CID-META: VersionHash:d497b38,CLOUDID:8d415428-5828-476d-aebd-a08d0b641e9a,B ulkID:nil,BulkQuantity:0,SF:102|836|865|888|898,TC:-5,Content:0|15|50,EDM: -3,IP:nil,URL:0,File:130,RT:0,Bulk:nil,QS:nil,BEC:-1,COL:0,OSI:0,OSA:0,AV: 0,LES:1,SPR:NO,DKR:0,DKP:0,BRR:0,BRE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: 96919ea86f7911f18dc8c9802ae25ab1-20260624 Received: from mtkmbs13n1.mediatek.inc [(172.21.101.193)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 192216690; Wed, 24 Jun 2026 11:05:43 +0800 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by MTKMBS09N2.mediatek.inc (172.21.101.94) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.29; Wed, 24 Jun 2026 11:05:42 +0800 Received: from mtksitap99.mediatek.inc (10.233.130.16) by mtkmbs11n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.2562.29 via Frontend Transport; Wed, 24 Jun 2026 11:05:42 +0800 From: Eason Lai To: , CC: , , , , , , , , , , , , Eason Lai Subject: [PATCH v4 1/1] wifi: mt76: mt792x: fix use-after-free in mt76_rx_poll_complete Date: Wed, 24 Jun 2026 11:05:11 +0800 Message-ID: <20260624030511.1197942-1-eason.lai@mediatek.com> X-Mailer: git-send-email 2.45.2 Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain From: Eason Lai A use-after-free issue occurs in mt76_rx_poll_complete due to a race condition. The STA has already been removed, but the rx_status still had a pointer to the wcid in the STA. Set the links' wcid pointers to be NULL for a MLD in mt7925_sta_pre_rcu_remove() BUG: KASAN: invalid-access in mt76_rx_poll_complete+0x280/0x470 Call trace: dump_backtrace+0xec/0x128 show_stack+0x18/0x28 dump_stack_lvl+0x40/0xc8 print_report+0x1b8/0x710 kasan_report+0xe0/0x144 do_bad_area+0x120/0x260 do_tag_check_fault+0x20/0x34 do_mem_abort+0x54/0xa8 el1_abort+0x3c/0x5c el1h_64_sync_handler+0x40/0xcc el1h_64_sync+0x7c/0x80 mt76_rx_poll_complete+0x280/0x470 mt76_dma_rx_poll+0x114/0x51c mt792x_poll_rx+0x60/0xf8 napi_threaded_poll_loop+0xe0/0x450 napi_threaded_poll+0x80/0x9c kthread+0x11c/0x158 ret_from_fork+0x10/0x20 Fixes: c948b5da6bbe ("wifi: mt76: mt7925: add Mediatek Wi-Fi7 driver for mt7925 chips") Signed-off-by: Eason Lai --- v2: fix mt76x02 build errors v3: fix mt76x02 build error due to variable set but not used v4: fix use-after-free in MLO --- .../net/wireless/mediatek/mt76/mt7925/main.c | 36 ++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/main.c b/drivers/net/wireless/mediatek/mt76/mt7925/main.c index 73d3722739d0..e3fb6392eda2 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7925/main.c +++ b/drivers/net/wireless/mediatek/mt76/mt7925/main.c @@ -2410,6 +2410,40 @@ static void mt7925_channel_switch_rx_beacon(struct ieee80211_hw *hw, } } +static void mt7925_sta_pre_rcu_remove(struct ieee80211_hw *hw, + struct ieee80211_vif *vif, + struct ieee80211_sta *sta) +{ + struct mt76_phy *phy = hw->priv; + struct mt76_dev *dev = phy->dev; + struct mt76_wcid *wcid = (struct mt76_wcid *)sta->drv_priv; + + mutex_lock(&dev->mutex); + spin_lock_bh(&dev->status_lock); + + if (ieee80211_vif_is_mld(vif)) { + struct mt792x_sta *msta = (struct mt792x_sta *)sta->drv_priv; + struct mt792x_vif *mvif = (struct mt792x_vif *)vif->drv_priv; + unsigned long valid = mvif->valid_links; + struct mt792x_link_sta *mlink; + unsigned int link_id; + + for_each_set_bit(link_id, &valid, IEEE80211_MLD_MAX_NUM_LINKS) { + mlink = mt792x_sta_to_link(msta, link_id); + if (!mlink || !mlink->wcid.sta) + continue; + if (mlink->wcid.idx < ARRAY_SIZE(dev->wcid)) + rcu_assign_pointer(dev->wcid[mlink->wcid.idx], + NULL); + } + } else { + rcu_assign_pointer(dev->wcid[wcid->idx], NULL); + } + + spin_unlock_bh(&dev->status_lock); + mutex_unlock(&dev->mutex); +} + const struct ieee80211_ops mt7925_ops = { .tx = mt792x_tx, .start = mt7925_start, @@ -2422,7 +2456,7 @@ const struct ieee80211_ops mt7925_ops = { .start_ap = mt7925_start_ap, .stop_ap = mt7925_stop_ap, .sta_state = mt76_sta_state, - .sta_pre_rcu_remove = mt76_sta_pre_rcu_remove, + .sta_pre_rcu_remove = mt7925_sta_pre_rcu_remove, .set_key = mt7925_set_key, .sta_set_decap_offload = mt7925_sta_set_decap_offload, #if IS_ENABLED(CONFIG_IPV6) -- 2.45.2