From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0DA50C433EF for ; Wed, 10 Nov 2021 18:54:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED653611C9 for ; Wed, 10 Nov 2021 18:54:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232784AbhKJS5l (ORCPT ); Wed, 10 Nov 2021 13:57:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:53386 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233677AbhKJSzb (ORCPT ); Wed, 10 Nov 2021 13:55:31 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8FD6661353; Wed, 10 Nov 2021 18:49:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636570161; bh=EEEm82jlH6LelDgraPELcEi79deedFAhsw4ZNvcvYCk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tvdcIVXaXABWw78G2gX9w47Nrr7v7r9pWTbDt9tDO1rKzULs2g//au622JP+/o/+p gEu/ygpVBDPy385PGhMeeKOsmBsgGKqa4yEm6dLRQuF+Vr7ejZDWRKIS2B6rdzZGyd VUoXejJXgHbRZ+F50FDIqSUygI2W5jxx2tZZI9b0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johan Hovold , Ian Abbott Subject: [PATCH 5.14 18/24] comedi: vmk80xx: fix transfer-buffer overflows Date: Wed, 10 Nov 2021 19:44:10 +0100 Message-Id: <20211110182003.920179667@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211110182003.342919058@linuxfoundation.org> References: <20211110182003.342919058@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johan Hovold commit a23461c47482fc232ffc9b819539d1f837adf2b1 upstream. The driver uses endpoint-sized USB transfer buffers but up until recently had no sanity checks on the sizes. Commit e1f13c879a7c ("staging: comedi: check validity of wMaxPacketSize of usb endpoints found") inadvertently fixed NULL-pointer dereferences when accessing the transfer buffers in case a malicious device has a zero wMaxPacketSize. Make sure to allocate buffers large enough to handle also the other accesses that are done without a size check (e.g. byte 18 in vmk80xx_cnt_insn_read() for the VMK8061_MODEL) to avoid writing beyond the buffers, for example, when doing descriptor fuzzing. The original driver was for a low-speed device with 8-byte buffers. Support was later added for a device that uses bulk transfers and is presumably a full-speed device with a maximum 64-byte wMaxPacketSize. Fixes: 985cafccbf9b ("Staging: Comedi: vmk80xx: Add k8061 support") Cc: stable@vger.kernel.org # 2.6.31 Signed-off-by: Johan Hovold Reviewed-by: Ian Abbott Link: https://lore.kernel.org/r/20211025114532.4599-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/comedi/drivers/vmk80xx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/comedi/drivers/vmk80xx.c +++ b/drivers/comedi/drivers/vmk80xx.c @@ -90,6 +90,8 @@ enum { #define IC3_VERSION BIT(0) #define IC6_VERSION BIT(1) +#define MIN_BUF_SIZE 64 + enum vmk80xx_model { VMK8055_MODEL, VMK8061_MODEL @@ -678,12 +680,12 @@ static int vmk80xx_alloc_usb_buffers(str struct vmk80xx_private *devpriv = dev->private; size_t size; - size = usb_endpoint_maxp(devpriv->ep_rx); + size = max(usb_endpoint_maxp(devpriv->ep_rx), MIN_BUF_SIZE); devpriv->usb_rx_buf = kzalloc(size, GFP_KERNEL); if (!devpriv->usb_rx_buf) return -ENOMEM; - size = usb_endpoint_maxp(devpriv->ep_tx); + size = max(usb_endpoint_maxp(devpriv->ep_rx), MIN_BUF_SIZE); devpriv->usb_tx_buf = kzalloc(size, GFP_KERNEL); if (!devpriv->usb_tx_buf) return -ENOMEM;