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From e75dc677ff8d06ffa61bef6fee436227ae5440c6 Mon Sep 17 00:00:00 2001
From: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
Date: Wed, 21 Aug 2013 01:43:19 -0700
Subject: [PATCH 2/2] 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>
---
drivers/net/usb/hso.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -2838,13 +2838,16 @@ 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;
}
@@ -2895,6 +2898,7 @@ static int hso_get_config_data(struct us
if (config_data[16] & 0x1)
result |= HSO_INFO_CRC_BUG;
+ kfree(config_data);
return result;
}
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