From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E1ED4374A0E; Thu, 30 Jul 2026 15:18:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785424696; cv=none; b=NBYzapawl48W4i9KbyPdKsdRxktdPVPGywlUHiGjKb+UKVE4cJaqRbxMx2Xg5B2xwf1FzL8iviFesAcEu9BOoe3P4H5W3rDRcnESiibFHTuKMTWB8sjWbU0HG93Ey5RaQ/Gv61nYHUWw5mQzRBSAf+wr9EwEvHtX42QdvIBNQ58= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785424696; c=relaxed/simple; bh=ChlBbf/uQBAirJ2hnmOkSPdoczMhR//rwjPxXD9rJtw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ltB0CZUa/l9m+vhnO9PeESCmaRObSfdqS3Aswb3yov8MvrffCSk1oI+aN6OOrsbanc7de8UVA4eErJyM0DbUTUv8zoulxaonoRndrOfKDED182ae2/ReefMIviF84oKQnSWJ3e5bU+IZYSIHaUDo7qZn6KAJ2mTiIF+6NR4QbNg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=B01t6XTg; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="B01t6XTg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4770F1F00A3A; Thu, 30 Jul 2026 15:18:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785424694; bh=hMykx5iUOgmNf0xCcWR4E4LbUm6VxqLjJ/hmiAuRGjI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=B01t6XTgsn3xHam+tbN1AmA3IiV+isj4f6jqVbeXOxjImnktVaZ2500bY94z69k9g NpzP11iWbpy0O6BGae5if0idHIHZIIQP44TI7/qjXZjC1RwFdiTsr/lSubHUY1Zv1f /38BL27p4oMW52CdeucATq2a0gqk1DLcqRmZH5l4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Devin Wittmayer , Felix Fietkau Subject: [PATCH 6.18 457/675] wifi: mt76: mt7921: drop TXRX_NOTIFY on non-mmio buses Date: Thu, 30 Jul 2026 16:13:07 +0200 Message-ID: <20260730141454.845002723@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141445.110192266@linuxfoundation.org> References: <20260730141445.110192266@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Devin Wittmayer commit da4082e91acabc1498611ed8ccc53f0610baefc6 upstream. PKT_TYPE_TXRX_NOTIFY is an mmio-only event, but mt7921_rx_check() and mt7921_queue_rx_skb() dispatch it to mt7921_mac_tx_free() on every bus. mt7921_mac_tx_free() cleans the DMA tx queues with mt76_queue_tx_cleanup(), which calls queue_ops->tx_cleanup(). Only the mmio queue ops implement that callback; on USB and SDIO it is NULL, so a TXRX_NOTIFY there calls a NULL pointer in the RX worker: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:0x0 Call Trace: mt7921_mac_tx_free+0x64/0x310 [mt7921_common] mt7921_rx_check+0x5f/0xf0 [mt7921_common] mt76u_rx_worker+0x1b9/0x620 [mt76_usb] Drop the event on non-mmio buses via mt76_is_mmio(), as in commit 5683e1488aa9 ("wifi: mt76: connac: do not check WED status for non-mmio devices"). Fixes: 48fab5bbef40 ("mt76: mt7921: introduce mt7921s support") Cc: stable@vger.kernel.org Signed-off-by: Devin Wittmayer Link: https://patch.msgid.link/20260627191336.20223-2-lucid_duck@justthetip.ca Signed-off-by: Felix Fietkau Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/mediatek/mt76/mt7921/mac.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c @@ -569,8 +569,9 @@ bool mt7921_rx_check(struct mt76_dev *md switch (type) { case PKT_TYPE_TXRX_NOTIFY: - /* PKT_TYPE_TXRX_NOTIFY can be received only by mmio devices */ - mt7921_mac_tx_free(dev, data, len); /* mmio */ + if (!mt76_is_mmio(mdev)) + return false; + mt7921_mac_tx_free(dev, data, len); return false; case PKT_TYPE_TXS: for (rxd += 2; rxd + 8 <= end; rxd += 8) @@ -599,7 +600,10 @@ void mt7921_queue_rx_skb(struct mt76_dev switch (type) { case PKT_TYPE_TXRX_NOTIFY: - /* PKT_TYPE_TXRX_NOTIFY can be received only by mmio devices */ + if (!mt76_is_mmio(mdev)) { + napi_consume_skb(skb, 1); + break; + } mt7921_mac_tx_free(dev, skb->data, skb->len); napi_consume_skb(skb, 1); break;