[083/141] USB: mos7720: fix DMA to stack

Steven Rostedt
2013-07-03T19:03:18Z

[-- Attachment #1: 0083-USB-mos7720-fix-DMA-to-stack.patch --]
[-- Type: text/plain, Size: 1543 bytes --]

3.6.11.6 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Johan Hovold <jhovold@gmail.com>

[ Upstream commit 72ea18a558ed7a63a50bb121ba60d73b5b38ae30 ]

The read_mos_reg function is called with stack-allocated buffers, which
must not be used for control messages.

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
drivers/usb/serial/mos7720.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
index eb84767..5b824d9 100644
--- a/drivers/usb/serial/mos7720.c
+++ b/drivers/usb/serial/mos7720.c
@@ -234,11 +234,22 @@ static int read_mos_reg(struct usb_serial *serial, unsigned int serial_portnum,
__u8 requesttype = (__u8)0xc0;
__u16 index = get_reg_index(reg);
__u16 value = get_reg_value(reg, serial_portnum);
- int status = usb_control_msg(usbdev, pipe, request, requesttype, value,
- index, data, 1, MOS_WDR_TIMEOUT);
- if (status < 0)
+ u8 *buf;
+ int status;
+
+ buf = kmalloc(1, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ status = usb_control_msg(usbdev, pipe, request, requesttype, value,
+ index, buf, 1, MOS_WDR_TIMEOUT);
+ if (status == 1)
+ *data = *buf;
+ else if (status < 0)
dev_err(&usbdev->dev,
"mos7720: usb_control_msg() failed: %d", status);
+ kfree(buf);
+
return status;
}

--
1.7.10.4