hso: Fix stack corruption on some architectures

As Sergei Shtylyov explained in the #mipslinux IRC channel:
[Mon 2013-08-19 12:28:21 PM PDT] <headless> guys, are you sure it's not "DMA off stack" case?
[Mon 2013-08-19 12:28:35 PM PDT] <headless> it's a known stack corruptor on non-coherent arches
[Mon 2013-08-19 12:31:48 PM PDT] <DonkeyHotei> headless: for usb/ehci?
[Mon 2013-08-19 12:34:11 PM PDT] <DonkeyHotei> headless: explain
[Mon 2013-08-19 12:35:38 PM PDT] <headless> usb_control_msg() (or other such func) should not use buffer on stack. DMA from/to stack is prohibited
[Mon 2013-08-19 12:35:58 PM PDT] <headless> and EHCI uses DMA on control xfers (as well as all the others)

Signed-off-by: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Gimpelevich 2013-08-21 01:43:19 -07:00 committed by David S. Miller
parent 35e57e1b49
commit e75dc677ff

View File

@ -2816,13 +2816,16 @@ struct hso_shared_int *hso_create_shared_int(struct usb_interface *interface)
static int hso_get_config_data(struct usb_interface *interface)
{
struct usb_device *usbdev = interface_to_usbdev(interface);
u8 config_data[17];
u8 *config_data = kmalloc(17, GFP_KERNEL);
u32 if_num = interface->altsetting->desc.bInterfaceNumber;
s32 result;
if (!config_data)
return -ENOMEM;
if (usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0),
0x86, 0xC0, 0, 0, config_data, 17,
USB_CTRL_SET_TIMEOUT) != 0x11) {
kfree(config_data);
return -EIO;
}
@ -2873,6 +2876,7 @@ static int hso_get_config_data(struct usb_interface *interface)
if (config_data[16] & 0x1)
result |= HSO_INFO_CRC_BUG;
kfree(config_data);
return result;
}