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 4C86D34D385; Thu, 30 Jul 2026 14:46:09 +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=1785422770; cv=none; b=HaEZgRcTyDwNio8Nb8c8uBlY8RXt1NlDwU9mb4ml844IlrL2YLDsb0TQjl089yyn3R5FjWD5ypXujBwqJ+krBNzZpSgCIMt3CkXkMSnM9QBYtv7jG6/dssIBa0Uq6Ft/q58SI4ALWdmHOz77p4qUlu0Ca2MwFAA6cOlzifqFQi0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785422770; c=relaxed/simple; bh=gLloH1QMELvuD48IUubx6cGPa270GZeuBnp0OMra230=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=T84fCfxaLmZLxOmwf0r26ES5Yd2T+6Viz5Hjal+DY5RDNxOWQJMngcmYlcU8tAN8JoTHHpKr4jcDhzJzE1fR6jd2UA5Mf6gKBGEaheUy3MsrxpbZPW07wuDZc2c1Zne3EjVGAvXnuXbuWFyFJHC91egQ2/u1fubgmJMzOFDVgBo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=2DeVv48O; 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="2DeVv48O" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7A861F000E9; Thu, 30 Jul 2026 14:46:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785422769; bh=MKLTjPo0MxO/khkoyXCoRNC1a7RsjLMVxCmWwUb5v6A=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=2DeVv48OQoOsNzTQ+kqYz+MK4Beji490QM7crYAJYlvwvGX6VH2KlqAYesaP323Ie GBHuY6HwMGICaJAByK9xoNwGZtjbJm6ynWScTdJwioxzsQz6OnvZsDxBC+xXsWmW2t di1CU5OnSL+D1rmHK3Dva0300TVRZC3dqUVhOSG4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Devin Wittmayer , Felix Fietkau Subject: [PATCH 7.1 548/744] wifi: mt76: mt7921: drop TXRX_NOTIFY on non-mmio buses Date: Thu, 30 Jul 2026 16:13:41 +0200 Message-ID: <20260730141455.923707733@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141444.267951807@linuxfoundation.org> References: <20260730141444.267951807@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 7.1-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;