Commit e75dc677 authored Aug 21, 2013 by Daniel Gimpelevich Committed by David S. Miller Aug 21, 2013

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>

parent 35e57e1b

drivers/net/usb/hso.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -2816,13 +2816,16 @@ exit:
		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;
		}

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