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 D6118C433F5 for ; Wed, 10 Nov 2021 18:56:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF65960FC2 for ; Wed, 10 Nov 2021 18:56:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234020AbhKJS7i (ORCPT ); Wed, 10 Nov 2021 13:59:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:54864 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233702AbhKJS5d (ORCPT ); Wed, 10 Nov 2021 13:57:33 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0496561A35; Wed, 10 Nov 2021 18:50:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636570222; bh=ZYvJ7ogo0gIRKKqhMit7XvxuzwMWtcL54MW/24Up8+E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EMowdoqJWoCRbqiyg2xrQLet9ks2EgOqJ8vGlJmDXjohplEkU93XyLRjb4ekla0aR 7efVXYQV0L3dvn7ksqXMUD4abcmb8HP7NHaTGnWJokH7SCP6LvkdBpv64z541QWci2 e4uMX4GljxcE58n1MzFnkbUdkaX+h2N1R8tdkk98= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ian Abbott , Johan Hovold Subject: [PATCH 5.15 17/26] comedi: dt9812: fix DMA buffers on stack Date: Wed, 10 Nov 2021 19:44:16 +0100 Message-Id: <20211110182004.238851070@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211110182003.700594531@linuxfoundation.org> References: <20211110182003.700594531@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 536de747bc48262225889a533db6650731ab25d3 upstream. USB transfer buffers are typically mapped for DMA and must not be allocated on the stack or transfers will fail. Allocate proper transfer buffers in the various command helpers and return an error on short transfers instead of acting on random stack data. Note that this also fixes a stack info leak on systems where DMA is not used as 32 bytes are always sent to the device regardless of how short the command is. Fixes: 63274cd7d38a ("Staging: comedi: add usb dt9812 driver") Cc: stable@vger.kernel.org # 2.6.29 Reviewed-by: Ian Abbott Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20211027093529.30896-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/comedi/drivers/dt9812.c | 115 +++++++++++++++++++++++++++++----------- 1 file changed, 86 insertions(+), 29 deletions(-) --- a/drivers/comedi/drivers/dt9812.c +++ b/drivers/comedi/drivers/dt9812.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include "../comedi_usb.h" @@ -237,22 +238,42 @@ static int dt9812_read_info(struct comed { struct usb_device *usb = comedi_to_usb_dev(dev); struct dt9812_private *devpriv = dev->private; - struct dt9812_usb_cmd cmd; + struct dt9812_usb_cmd *cmd; + size_t tbuf_size; int count, ret; + void *tbuf; - cmd.cmd = cpu_to_le32(DT9812_R_FLASH_DATA); - cmd.u.flash_data_info.address = + tbuf_size = max(sizeof(*cmd), buf_size); + + tbuf = kzalloc(tbuf_size, GFP_KERNEL); + if (!tbuf) + return -ENOMEM; + + cmd = tbuf; + + cmd->cmd = cpu_to_le32(DT9812_R_FLASH_DATA); + cmd->u.flash_data_info.address = cpu_to_le16(DT9812_DIAGS_BOARD_INFO_ADDR + offset); - cmd.u.flash_data_info.numbytes = cpu_to_le16(buf_size); + cmd->u.flash_data_info.numbytes = cpu_to_le16(buf_size); /* DT9812 only responds to 32 byte writes!! */ ret = usb_bulk_msg(usb, usb_sndbulkpipe(usb, devpriv->cmd_wr.addr), - &cmd, 32, &count, DT9812_USB_TIMEOUT); + cmd, sizeof(*cmd), &count, DT9812_USB_TIMEOUT); if (ret) - return ret; + goto out; + + ret = usb_bulk_msg(usb, usb_rcvbulkpipe(usb, devpriv->cmd_rd.addr), + tbuf, buf_size, &count, DT9812_USB_TIMEOUT); + if (!ret) { + if (count == buf_size) + memcpy(buf, tbuf, buf_size); + else + ret = -EREMOTEIO; + } +out: + kfree(tbuf); - return usb_bulk_msg(usb, usb_rcvbulkpipe(usb, devpriv->cmd_rd.addr), - buf, buf_size, &count, DT9812_USB_TIMEOUT); + return ret; } static int dt9812_read_multiple_registers(struct comedi_device *dev, @@ -261,22 +282,42 @@ static int dt9812_read_multiple_register { struct usb_device *usb = comedi_to_usb_dev(dev); struct dt9812_private *devpriv = dev->private; - struct dt9812_usb_cmd cmd; + struct dt9812_usb_cmd *cmd; int i, count, ret; + size_t buf_size; + void *buf; + + buf_size = max_t(size_t, sizeof(*cmd), reg_count); + + buf = kzalloc(buf_size, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + cmd = buf; - cmd.cmd = cpu_to_le32(DT9812_R_MULTI_BYTE_REG); - cmd.u.read_multi_info.count = reg_count; + cmd->cmd = cpu_to_le32(DT9812_R_MULTI_BYTE_REG); + cmd->u.read_multi_info.count = reg_count; for (i = 0; i < reg_count; i++) - cmd.u.read_multi_info.address[i] = address[i]; + cmd->u.read_multi_info.address[i] = address[i]; /* DT9812 only responds to 32 byte writes!! */ ret = usb_bulk_msg(usb, usb_sndbulkpipe(usb, devpriv->cmd_wr.addr), - &cmd, 32, &count, DT9812_USB_TIMEOUT); + cmd, sizeof(*cmd), &count, DT9812_USB_TIMEOUT); if (ret) - return ret; + goto out; - return usb_bulk_msg(usb, usb_rcvbulkpipe(usb, devpriv->cmd_rd.addr), - value, reg_count, &count, DT9812_USB_TIMEOUT); + ret = usb_bulk_msg(usb, usb_rcvbulkpipe(usb, devpriv->cmd_rd.addr), + buf, reg_count, &count, DT9812_USB_TIMEOUT); + if (!ret) { + if (count == reg_count) + memcpy(value, buf, reg_count); + else + ret = -EREMOTEIO; + } +out: + kfree(buf); + + return ret; } static int dt9812_write_multiple_registers(struct comedi_device *dev, @@ -285,19 +326,27 @@ static int dt9812_write_multiple_registe { struct usb_device *usb = comedi_to_usb_dev(dev); struct dt9812_private *devpriv = dev->private; - struct dt9812_usb_cmd cmd; + struct dt9812_usb_cmd *cmd; int i, count; + int ret; - cmd.cmd = cpu_to_le32(DT9812_W_MULTI_BYTE_REG); - cmd.u.read_multi_info.count = reg_count; + cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); + if (!cmd) + return -ENOMEM; + + cmd->cmd = cpu_to_le32(DT9812_W_MULTI_BYTE_REG); + cmd->u.read_multi_info.count = reg_count; for (i = 0; i < reg_count; i++) { - cmd.u.write_multi_info.write[i].address = address[i]; - cmd.u.write_multi_info.write[i].value = value[i]; + cmd->u.write_multi_info.write[i].address = address[i]; + cmd->u.write_multi_info.write[i].value = value[i]; } /* DT9812 only responds to 32 byte writes!! */ - return usb_bulk_msg(usb, usb_sndbulkpipe(usb, devpriv->cmd_wr.addr), - &cmd, 32, &count, DT9812_USB_TIMEOUT); + ret = usb_bulk_msg(usb, usb_sndbulkpipe(usb, devpriv->cmd_wr.addr), + cmd, sizeof(*cmd), &count, DT9812_USB_TIMEOUT); + kfree(cmd); + + return ret; } static int dt9812_rmw_multiple_registers(struct comedi_device *dev, @@ -306,17 +355,25 @@ static int dt9812_rmw_multiple_registers { struct usb_device *usb = comedi_to_usb_dev(dev); struct dt9812_private *devpriv = dev->private; - struct dt9812_usb_cmd cmd; + struct dt9812_usb_cmd *cmd; int i, count; + int ret; + + cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); + if (!cmd) + return -ENOMEM; - cmd.cmd = cpu_to_le32(DT9812_RMW_MULTI_BYTE_REG); - cmd.u.rmw_multi_info.count = reg_count; + cmd->cmd = cpu_to_le32(DT9812_RMW_MULTI_BYTE_REG); + cmd->u.rmw_multi_info.count = reg_count; for (i = 0; i < reg_count; i++) - cmd.u.rmw_multi_info.rmw[i] = rmw[i]; + cmd->u.rmw_multi_info.rmw[i] = rmw[i]; /* DT9812 only responds to 32 byte writes!! */ - return usb_bulk_msg(usb, usb_sndbulkpipe(usb, devpriv->cmd_wr.addr), - &cmd, 32, &count, DT9812_USB_TIMEOUT); + ret = usb_bulk_msg(usb, usb_sndbulkpipe(usb, devpriv->cmd_wr.addr), + cmd, sizeof(*cmd), &count, DT9812_USB_TIMEOUT); + kfree(cmd); + + return ret; } static int dt9812_digital_in(struct comedi_device *dev, u8 *bits)