From patchwork Sat Nov 23 23:54:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Foster Snowhill X-Patchwork-Id: 13883985 Received: from pv50p00im-ztdg10012001.me.com (pv50p00im-ztdg10012001.me.com [17.58.6.51]) (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 837021ABEA1 for ; Sat, 23 Nov 2024 23:55:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=17.58.6.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732406140; cv=none; b=BFj1mnVbKMTT1UEjxqjmZ+X180T+NLyyu4X0X/oNjz6HSD2oAjm4ov4WMghkk/ewYprnXzVgkoy7iDkp7YUbszmPHNC9uZGUrKu5oQG6zRpAKgYFJgnEsjsMb2E+2UlEP1nhAOZHdysXP6P1jciW/iP3y0zU500xrPb6hs3w7x4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732406140; c=relaxed/simple; bh=mSKgNv+8pEY9lOW+d989YvSCydnI59nBODLjbYnN1uc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oRJMVlAnFZ07zc74fF5xfeqvHtO4UpbVFuRPFjNiXPvOkbzeYSk5pHuFp5fvf/ysAv7hfmx9AbDJHXQhe/3BoJ4vFyWH+LmJQPtyCt1bkzf+rvgPcbZTUWHbfy/2trjP8yNQBRInwznpCMo3LJsmzAW6PPa8E+VKS3e5wmStDJg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=pen.gy; spf=pass smtp.mailfrom=pen.gy; dkim=pass (2048-bit key) header.d=pen.gy header.i=@pen.gy header.b=JbJodhNX; arc=none smtp.client-ip=17.58.6.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=pen.gy Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pen.gy Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=pen.gy header.i=@pen.gy header.b="JbJodhNX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pen.gy; s=sig1; t=1732406137; bh=NCS0BS66uf7Asgthxy+WGil5SatQ+cnWgHoOGK0eBeY=; h=From:To:Subject:Date:Message-ID:MIME-Version:x-icloud-hme; b=JbJodhNXraoXEngwxXM7ASHn1EXDfQsVrHos4K/sn9iuZmuoSE4QRiSGQrN22taq0 3HY/PFdYT5PCXLT7bsX5XUcDKGNr1DmqEdwhj3hF0yQfZeAEpfE6XRluGHI/R4LHBc nh8wFVxBdsReXUe2Lti4IfaCIjfp+NXeJE+xX8JnSI6WQZ+2rsAJ4NKoFOGcOJIf9f UwBz01xGpVIZwn3jJhqeqm12urcfI3D25Kfxww+AeaDFADGAylfjYzsDhaEomFkl/8 wVJgL2ieucf+KWRjLaPQMA5Yd/0b3soWecLjGffI+5B1ONFKZjktyE+mOwEYGI9qN3 oJ8Wjf2JzUsZQ== Received: from fossa.se1.pen.gy (pv50p00im-dlb-asmtp-mailmevip.me.com [17.56.9.10]) by pv50p00im-ztdg10012001.me.com (Postfix) with ESMTPSA id 25801A006F; Sat, 23 Nov 2024 23:55:32 +0000 (UTC) From: Foster Snowhill To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Georgi Valkov , Simon Horman , Oliver Neukum , netdev@vger.kernel.org, linux-usb@vger.kernel.org Subject: [PATCH net v3 5/6] usbnet: ipheth: refactor NCM datagram loop, fix DPE OoB read Date: Sun, 24 Nov 2024 00:54:31 +0100 Message-ID: <20241123235432.821220-5-forst@pen.gy> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20241123235432.821220-1-forst@pen.gy> References: <20241123235432.821220-1-forst@pen.gy> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Proofpoint-GUID: twy898kQTSRr558DFtDHPKr2za0R4I2r X-Proofpoint-ORIG-GUID: twy898kQTSRr558DFtDHPKr2za0R4I2r X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-11-23_19,2024-11-21_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 bulkscore=0 suspectscore=0 mlxlogscore=741 malwarescore=0 clxscore=1030 spamscore=0 mlxscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2308100000 definitions=main-2411230200 Introduce an rx_error label to reduce repetitions in the header signature checks. Store wDatagramIndex and wDatagramLength after endianness conversion to avoid repeated le16_to_cpu() calls. Rewrite the loop to return on a null trailing DPE, which is required by the CDC NCM spec. In case it is missing, fall through to rx_error. Fix an out-of-bounds DPE read, limit the number of processed DPEs to the amount that fits into the fixed-size NDP16 header. Fixes: a2d274c62e44 ("usbnet: ipheth: add CDC NCM support") Signed-off-by: Foster Snowhill --- v3: Split out from a monolithic patch in v2 as an atomic change. v2: https://lore.kernel.org/netdev/20240912211817.1707844-1-forst@pen.gy/ No code changes. Update commit message to further clarify that `ipheth` is not and does not aim to be a complete or spec-compliant CDC NCM implementation. v1: https://lore.kernel.org/netdev/20240907230108.978355-1-forst@pen.gy/ --- drivers/net/usb/ipheth.c | 44 +++++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 21 deletions(-) diff --git a/drivers/net/usb/ipheth.c b/drivers/net/usb/ipheth.c index 3f9ea6546720..122557b5e5a9 100644 --- a/drivers/net/usb/ipheth.c +++ b/drivers/net/usb/ipheth.c @@ -224,9 +224,9 @@ static int ipheth_rcvbulk_callback_ncm(struct urb *urb) struct usb_cdc_ncm_ndp16 *ncm0; struct usb_cdc_ncm_dpe16 *dpe; struct ipheth_device *dev; + u16 dg_idx, dg_len; int retval = -EINVAL; char *buf; - int len; dev = urb->context; @@ -236,40 +236,42 @@ static int ipheth_rcvbulk_callback_ncm(struct urb *urb) } ncmh = urb->transfer_buffer; - if (ncmh->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) { - dev->net->stats.rx_errors++; - return retval; - } + if (ncmh->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN)) + goto rx_error; /* On iOS, NDP16 directly follows NTH16 */ ncm0 = urb->transfer_buffer + sizeof(struct usb_cdc_ncm_nth16); - if (ncm0->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN)) { - dev->net->stats.rx_errors++; - return retval; - } + if (ncm0->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN)) + goto rx_error; dpe = ncm0->dpe16; - while (le16_to_cpu(dpe->wDatagramIndex) != 0 && - le16_to_cpu(dpe->wDatagramLength) != 0) { - if (le16_to_cpu(dpe->wDatagramIndex) < IPHETH_NCM_HEADER_SIZE || - le16_to_cpu(dpe->wDatagramIndex) >= urb->actual_length || - le16_to_cpu(dpe->wDatagramLength) > urb->actual_length - - le16_to_cpu(dpe->wDatagramIndex)) { + for (int dpe_i = 0; dpe_i < IPHETH_NDP16_MAX_DPE; ++dpe_i, ++dpe) { + dg_idx = le16_to_cpu(dpe->wDatagramIndex); + dg_len = le16_to_cpu(dpe->wDatagramLength); + + /* Null DPE must be present after last datagram pointer entry + * (3.3.1 USB CDC NCM spec v1.0) + */ + if (dg_idx == 0 && dg_len == 0) + return 0; + + if (dg_idx < IPHETH_NCM_HEADER_SIZE || + dg_idx >= urb->actual_length || + dg_len > urb->actual_length - dg_idx) { dev->net->stats.rx_length_errors++; return retval; } - buf = urb->transfer_buffer + le16_to_cpu(dpe->wDatagramIndex); - len = le16_to_cpu(dpe->wDatagramLength); + buf = urb->transfer_buffer + dg_idx; - retval = ipheth_consume_skb(buf, len, dev); + retval = ipheth_consume_skb(buf, dg_len, dev); if (retval != 0) return retval; - - dpe++; } - return 0; +rx_error: + dev->net->stats.rx_errors++; + return retval; } static void ipheth_rcvbulk_callback(struct urb *urb)