From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx.swemel.ru (mx.swemel.ru [95.143.211.150]) (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 AF8333955C3; Tue, 1 Sep 2026 09:04:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.143.211.150 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788253463; cv=none; b=P+F1FfgMz/JqiQP6S3aXRfPnzJt5XydVq9Cw/QCmJL9ShcHLjDpRj6mvmcZZ8L09ZW406R/noxXVbxewD1mGCodasvzhyI11rZjUaQaAgAVSioGhzgpTLJm399Kqp+kBIylWJUJbQaxIyDrURR85DHAFMvPIENZ9sNzLKqgF720= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788253463; c=relaxed/simple; bh=LTI8q0Epg6Ut8DoCocYaTVrkvbZWppAJSxZWpWWifWE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=cb6lR8FMO37ggKwj/kUEynKQqh3v3X27pqcmPmDjJMK4/I6zZAu1dvWLh5RpLgnvwQ6x382lUdHhAEVZ+QGw0MaR9jLMjpeu1jxXBnevylmp2XjUCzkaOHcYNkhBVin7cnghureFdGzcFhKfteEVOa00UUxl5mu9C6bXvov44gw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=swemel.ru; spf=pass smtp.mailfrom=swemel.ru; dkim=pass (1024-bit key) header.d=swemel.ru header.i=@swemel.ru header.b=bdXY9cRu; arc=none smtp.client-ip=95.143.211.150 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=swemel.ru Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=swemel.ru Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=swemel.ru header.i=@swemel.ru header.b="bdXY9cRu" From: Denis Arefev DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=swemel.ru; s=mail; t=1788253448; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=5RrptSmK1QMQpguF6j6YC9fFHhdiNT6BCnOECykAPBI=; b=bdXY9cRux1f0eydM3Nho/qef0dC9qkFezjTeFlVfdr1tMHx8v/kScmmEzjvf8svAd+s/mZ nu2SKTmB20PJUeGZM6Yna2bsoPnAXvZdO/fEHG1BmoWX6hjpXrmlIs2ufoWOP5SrY9082c Onx9Obp55ivVZcprhXvcG2JsnQevNfc= To: stable@vger.kernel.org, Greg Kroah-Hartman Cc: Wolfgang Grandegger , Marc Kleine-Budde , "David S. Miller" , Jakub Kicinski , Pengpeng Hou , Sebastian Haas , linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 5.10] can: ems_usb: validate CPC message lengths Date: Tue, 1 Sep 2026 12:04:06 +0300 Message-ID: <20260901090408.10353-1-arefev@swemel.ru> 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 commit 02925f51377f2a42a6724f00549167499c9302e5 upstream. 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 [Denis Arefev: adapted for 5.10: use get_can_dlc() instead of can_cc_dlc2len(), the latter was introduced in 6.x along with include/linux/can/length.h; get_can_dlc() has identical semantics for classic CAN frames (min(dlc, CAN_MAX_DLEN))] Signed-off-by: Denis Arefev --- Backport fix for CVE-2026-74460 Link: https://nvd.nist.gov/vuln/detail/CVE-2026-74460 --- 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 65aa1100e894..a645962da37a 100644 --- a/drivers/net/can/usb/ems_usb.c +++ b/drivers/net/can/usb/ems_usb.c @@ -402,6 +402,40 @@ 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 = get_can_dlc(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 */ @@ -444,6 +478,15 @@ 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: -- 2.43.0