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authorJohan Hovold <johan@kernel.org>2021-10-27 11:35:29 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-10-30 10:54:47 +0200
commit536de747bc48262225889a533db6650731ab25d3 (patch)
tree3df2148b413d031ca41cbc158920d8165d4c6924 /drivers/comedi
parent907767da8f3a925b060c740e0b5c92ea7dbec440 (diff)
downloadlinux-536de747bc48262225889a533db6650731ab25d3.tar.bz2
comedi: dt9812: fix DMA buffers on stack
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 <abbotti@mev.co.uk> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20211027093529.30896-3-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/comedi')
-rw-r--r--drivers/comedi/drivers/dt9812.c115
1 files 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 <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
+#include <linux/slab.h>
#include <linux/uaccess.h>
#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)