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 C0E6F4E235D; Wed, 30 Sep 2026 16:00:14 +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=1790784022; cv=none; b=eMUnOvPqC5Z6QMc315gFQ0HAx3KgZh6yM2n5h5HGK/OjqvEO9BqEsDlMppxTkq6XQOAPdbru7hKngdFDo1cXLOr6jj+Q/kKJysGdr0EppoDATWJxkvKoWm+oJrHfQT84/keu46ZT54KtF+AT6jUFbauA9q110gTrhEEd0g1pFok= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790784022; c=relaxed/simple; bh=kJItOpETsDiEFAsyHPnr9ix3lAHMIgJmHGHlN2U/w4o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eIIjxxm7j5+EHTPYvpHyicFSJ5VD1RZ4vKqYjykxBW9I0zge63wKNMjE2tlbVxWch/rZu+Lw7FvDPAK04M53X7NFLbBIlHP2YKT6OqEfFbvQFqdTpLOdRqq4N2gTa6/zYarzKwp+O1R6ZhlKIue7mQrNdkY5EmVrS7zZZBVf3V8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Jb6acRkE; 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="Jb6acRkE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD40A1F00893; Wed, 30 Sep 2026 16:00:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790784014; bh=OJlg8fjDj9ZoJhqE90NXNCSw3sODU0cGyqamfYiSLiI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Jb6acRkEX1mefEuOJU0zYw2EAG7dOhORb7uUafQHX/J/dku0m9GbKOTYZdGWoDMJC /v3TNlCP1eJKLgOq2/ZYduaSdOE16sbs6S5kJVcS3/Av1xWHEOH0ifkJbBMy6biN1i GgFokISieJSs8iAM3/xjD0YA1wiJzHqGKGbSoHBE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pengpeng Hou , Marc Kleine-Budde , Denis Arefev Subject: [PATCH 5.10 595/595] can: ems_usb: validate CPC message lengths Date: Wed, 30 Sep 2026 17:28:08 +0200 Message-ID: <20260930152400.535786822@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152347.700140858@linuxfoundation.org> References: <20260930152347.700140858@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/usb/ems_usb.c | 43 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) --- 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_us 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(s } 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: