From patchwork Wed Oct 27 09:35:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 12586833 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 66460C433FE for ; Wed, 27 Oct 2021 09:37:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4BCEF61056 for ; Wed, 27 Oct 2021 09:37:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241235AbhJ0JjY (ORCPT ); Wed, 27 Oct 2021 05:39:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:42322 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238859AbhJ0JjV (ORCPT ); Wed, 27 Oct 2021 05:39:21 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B79A161052; Wed, 27 Oct 2021 09:36:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1635327416; bh=w34sjWWnoH8USWkb6Lh268jrY7MkvGw0X2nThpeO9xA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DkF4yEox6FYj5CQPjGSPS+w20CY1G4DBKhOEc4JVyouLq3zydt9aX4R81SSZW1IDl VJKYYr5iTwNq65yDsqz9EYGK1QFtYI+vMu3VE9mFdzn554rYg8u7/mYDXSHw5/8aq4 7lQXs92tcvu/a1IxngXuubjd66eSqEoyoIutS0u0uf1xjLSrX8M2N1IZlBayje6XB/ 25ro00xwNYSx12RR6YoUai48t9ylZ8FfOM/FPn7lS4fXCCI8Kp36JedTTKcuA8vJq9 0T1LHPaKn2y3R/ggWyWqXgf0LLdZH65GIcKxgCZXYXbi7CyRi50Argnr/lmqE82OSW u0q5QL40F2Qcg== Received: from johan by xi.lan with local (Exim 4.94.2) (envelope-from ) id 1mffMP-00083c-5x; Wed, 27 Oct 2021 11:36:41 +0200 From: Johan Hovold To: Ian Abbott , H Hartley Sweeten Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , stable@vger.kernel.org Subject: [PATCH v2 2/2] comedi: dt9812: fix DMA buffers on stack Date: Wed, 27 Oct 2021 11:35:29 +0200 Message-Id: <20211027093529.30896-3-johan@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211027093529.30896-1-johan@kernel.org> References: <20211027093529.30896-1-johan@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org 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 Signed-off-by: Johan Hovold Reviewed-by: Ian Abbott --- drivers/comedi/drivers/dt9812.c | 115 ++++++++++++++++++++++++-------- 1 file changed, 86 insertions(+), 29 deletions(-) diff --git a/drivers/comedi/drivers/dt9812.c b/drivers/comedi/drivers/dt9812.c index 634f57730c1e..704b04d2980d 100644 --- 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 comedi_device *dev, { 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_registers(struct comedi_device *dev, { 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; - cmd.cmd = cpu_to_le32(DT9812_R_MULTI_BYTE_REG); - cmd.u.read_multi_info.count = reg_count; + 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; 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; + + 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 usb_bulk_msg(usb, usb_rcvbulkpipe(usb, devpriv->cmd_rd.addr), - value, reg_count, &count, DT9812_USB_TIMEOUT); + return ret; } static int dt9812_write_multiple_registers(struct comedi_device *dev, @@ -285,19 +326,27 @@ static int dt9812_write_multiple_registers(struct comedi_device *dev, { 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_W_MULTI_BYTE_REG); - cmd.u.read_multi_info.count = reg_count; + 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 comedi_device *dev, { 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)