From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.white.stw.pengutronix.de (mx1.white.stw.pengutronix.de [185.203.200.13]) (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 D3DEB3D3CE6; Wed, 29 Jul 2026 10:29:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.200.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785320971; cv=none; b=QUHHD5ZEYDzj9QGykoFSMD9JM2TYC6kBpWslgIRlbf2FYwVScYviL7s/j14AaQVHmH/SVIAwnzNHM4VlTyzsYWLAmOgBopy8p7CNieBUCEJNMenOZUHqK6IOZehuosdTaFY4ovzosi0G58kZfGasBX8AfTBmx46uxeFGlTRtt1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785320971; c=relaxed/simple; bh=60xJvWw3VwifiLzvhCenIBNnd4tNUOIRYTdCuGrJ2SM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QBB8l+MDaSIspOkMKEqKCiL1pdSCy6ghgNlx9h4wR0IlI42LZpt+tGB5+L1ps/Y7EGISPrMxD4Pkj5+cbbcZU57WAZEJZR/k9wD+ePYOVQI7E/gxl0J49RrxZXui570+Nc2cMQiFlDnY+9V3uRvTQNAYZGtBFcGaZMuArShrRZo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.200.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de (drehscheibe.grey.stw.pengutronix.de [IPv6:2a0a:edc0:0:c01:1d::a2]) (Authenticated sender: relay-from-drehscheibe.grey.stw.pengutronix.de) by mx1.white.stw.pengutronix.de (Postfix) with ESMTPSA id D2828201D85; Wed, 29 Jul 2026 12:29:25 +0200 (CEST) Received: from moin.white.stw.pengutronix.de ([2a0a:edc0:0:b01:1d::7b] helo=bjornoya.blackshift.org) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1wp1XR-001rmr-23; Wed, 29 Jul 2026 12:29:25 +0200 Received: from blackshift.org (p4ffb2dc6.dip0.t-ipconnect.de [79.251.45.198]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519MLKEM768 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: mkl-all@blackshift.org) by smtp.blackshift.org (Postfix) with ESMTPSA id 0975E575DE2; Wed, 29 Jul 2026 10:28:12 +0000 (UTC) From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Pengpeng Hou , stable@vger.kernel.org, Marc Kleine-Budde Subject: [PATCH net 20/20] can: ems_usb: validate CPC message lengths Date: Wed, 29 Jul 2026 12:13:00 +0200 Message-ID: <20260729102802.505168-21-mkl@pengutronix.de> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260729102802.505168-1-mkl@pengutronix.de> References: <20260729102802.505168-1-mkl@pengutronix.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Pengpeng Hou ems_usb_read_bulk_callback() walks CPC messages packed in one USB receive buffer. Check that each declared message fits in the URB payload. Also require the type-specific payload to cover the fields used by the CAN, state, error and overrun handlers. Signed-off-by: Pengpeng Hou Link: https://patch.msgid.link/20260706092752.79600-1-pengpeng@iscas.ac.cn Fixes: 702171adeed3 ("ems_usb: Added support for EMS CPC-USB/ARM7 CAN/USB interface") Cc: stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde --- drivers/net/can/usb/ems_usb.c | 43 +++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c index 9b25dda7c183..24cf8f651f8f 100644 --- a/drivers/net/can/usb/ems_usb.c +++ b/drivers/net/can/usb/ems_usb.c @@ -409,6 +409,40 @@ static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg) netif_rx(skb); } +static bool ems_usb_rx_msg_len_valid(struct ems_cpc_msg *msg) +{ + size_t len = msg->length; + size_t can_len; + + switch (msg->type) { + case CPC_MSG_TYPE_CAN_STATE: + return len >= sizeof(msg->msg.can_state); + + case CPC_MSG_TYPE_CAN_FRAME: + case CPC_MSG_TYPE_EXT_CAN_FRAME: + case CPC_MSG_TYPE_RTR_FRAME: + case CPC_MSG_TYPE_EXT_RTR_FRAME: + if (len < CPC_CAN_MSG_MIN_SIZE) + return false; + + if (msg->type == CPC_MSG_TYPE_RTR_FRAME || + msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) + return true; + + can_len = can_cc_dlc2len(msg->msg.can_msg.length & 0xf); + return len >= CPC_CAN_MSG_MIN_SIZE + can_len; + + case CPC_MSG_TYPE_CAN_FRAME_ERROR: + return len >= sizeof(msg->msg.error); + + case CPC_MSG_TYPE_OVERRUN: + return len >= sizeof(msg->msg.overrun); + + default: + return true; + } +} + /* * callback for bulk IN urb */ @@ -451,6 +485,15 @@ static void ems_usb_read_bulk_callback(struct urb *urb) } msg = (struct ems_cpc_msg *)&ibuf[start]; + if (msg->length > + urb->actual_length - start - CPC_MSG_HEADER_LEN) { + netdev_err(netdev, "format error\n"); + break; + } + if (!ems_usb_rx_msg_len_valid(msg)) { + netdev_err(netdev, "format error\n"); + break; + } switch (msg->type) { case CPC_MSG_TYPE_CAN_STATE: -- 2.53.0