From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792592156; b=2TzLRHk1A7isPclMTFOZ09QG88pa5HI7NvMiIs6cTsBXsaiChaOUj3aNgFSfOwXGOAEY YBf/7BR4Z1sIt+/VOdxx4vRCKV8o5BzUK8J3ZnJD8c8kcD1REVgg3XVFAkoxMpTOaTWQj PBncGqx8AOlqeQu6T5r7LbgmukEIqgQXIQoYmJpidrbdecUEK0FlzzulOgu1K7AMRvVRj pHSj2Mv8gnyGAf2DLaOP6erA/EQht0OQDfyJSAlZ+5fOZbQ3O7wzCCgNurt8SdtJSl1l3 MSmPY0XnkwMWfvVCcrg48/n10nej0dlfceLuAOR81mPbNn+w8b+7K//ouMOZWr15drw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792592156; h=Received:DKIM-Signature:Received:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=V6OicTVbtcTLzSS+UWGSsMNxNz1ZsX9m5t8h/aO5CmY=; b=Sj1E1+nkckxJyq1hQGf+bTQbcA5c+Yau7EL7jP2If+8PMrg+fL+KGhOuhpB5d5lFQqLP zo3hnFVApOlSiAebp8ctoippal+SN4qqyZmEfe3wTEm8Z0r/93YmGjDoa+eEgtaXPO2xO D8C1e8KOFkuWCR55aTN82r8OZLhA6kZxcGl40EEdYVDB9KsIU+CTVvZMqLz39zayBOZyq V429C7Tma60o+JQ/+TmrUNwNLTK0/K9gZDEw5kV5K8Bri9TZoMlvVCNH5/Q/m8zT+EnhV Sn7l0e++iiHhGHElVh7Gj38gU+kNHK6CxbiSG8LYd1lQ97nGX68VrcJCVPKBSwNV/LQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=jYn2KVjo; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7A152606A33B; Wed, 21 Oct 2026 14:15:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=jYn2KVjo Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32F4D1F000D3; Wed, 21 Oct 2026 14:15:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792592150; bh=V6OicTVbtcTLzSS+UWGSsMNxNz1ZsX9m5t8h/aO5CmY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jYn2KVjo7Z4y7FW3CtnSMVUkvWYq6S8KFPsgWkh2tLQSgKGhgofFfSRxou2It7VkE QiwYzAj/5Ob+k8X9rEZlFyVkDC6DiBkFJX1eFKnuESThD8ZxArYmCWIJM1XlPOWX4K I9+wVac09GCaZbENfFZKpqDVwbRYnvZwEjS+snU86S1/Y7SHz4cPK1cKVmWNn+8NDY 0ba2K+HCNRwQqn/LQiR/p3Mkp3xPeLMHIOEN2gYR5uzHrvb0UttV7sQmaym9GI6nrR 8FXFR8/s67vNtnrQs9dbCPwPUg12EEJmuh82R55AqcZZoRPM3hqICeN3no6HKNj8Eu r46kRMHL5Yk+w== Received: from johan by xi.lan with local (Exim 4.99.5) (envelope-from ) id 1xJX6Z-00000009kqB-2L13; Wed, 21 Oct 2026 16:15:47 +0200 From: Johan Hovold To: Johan Hovold Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 02/11] USB: serial: io_edgeport: fix potential fifo corruption Date: Wed, 21 Oct 2026 16:11:45 +0200 Message-ID: <20261021141154.2324793-3-johan@kernel.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261021141154.2324793-1-johan@kernel.org> References: <20261021141154.2324793-1-johan@kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The device buffer size is determined during open() and the driver allocates a TX FIFO of corresponding size. Add the missing sanity check to prevent memory corruption in case a malicious device sends a second open response with a different buffer size. This issue was flagged by Sashiko when reviewing a related fix. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Link: https://sashiko.dev/#/patchset/20260714101316.823942-1-shpark061104%40gmail.com?part=1 Signed-off-by: Johan Hovold --- drivers/usb/serial/io_edgeport.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c index cdf41e86ba44..0cc4f41299e0 100644 --- a/drivers/usb/serial/io_edgeport.c +++ b/drivers/usb/serial/io_edgeport.c @@ -878,7 +878,11 @@ static int edge_open(struct tty_struct *tty, struct usb_serial_port *port) } /* initialize our port settings */ + spin_lock_irq(&edge_port->ep_lock); edge_port->txCredits = 0; /* Can't send any data yet */ + edge_port->maxTxCredits = 0; + spin_unlock_irq(&edge_port->ep_lock); + /* Must always set this bit to enable ints! */ edge_port->shadowMCR = MCR_MASTER_IE; edge_port->chaseResponsePending = false; @@ -1750,6 +1754,7 @@ static void process_rcvd_status(struct edgeport_serial *edge_serial, struct tty_struct *tty; struct device *dev; __u8 code = edge_serial->rxStatusCode; + unsigned long flags; /* switch the port pointer to the one being currently talked about */ if (edge_serial->rxPort >= edge_serial->serial->num_ports) @@ -1793,10 +1798,17 @@ static void process_rcvd_status(struct edgeport_serial *edge_serial, } if (code == IOSP_STATUS_OPEN_RSP) { + spin_lock_irqsave(&edge_port->ep_lock, flags); + /* reject stray open responses to avoid FIFO corruption */ + if (edge_port->maxTxCredits != 0) { + spin_unlock_irqrestore(&edge_port->ep_lock, flags); + return; + } edge_port->txCredits = GET_TX_BUFFER_SIZE(byte3); edge_port->maxTxCredits = edge_port->txCredits; dev_dbg(dev, "%s - Port %u Open Response Initial MSR = %02x TxBufferSize = %d\n", __func__, edge_serial->rxPort, byte2, edge_port->txCredits); + spin_unlock_irqrestore(&edge_port->ep_lock, flags); handle_new_msr(edge_port, byte2); /* send the current line settings to the port so we are -- 2.55.0