[PATCH 2/2] hso: Fix stack corruption on some architectures
From: Daniel Gimpelevich <hidden>
Date: 2013-08-21 08:43:27
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 <redacted> --- drivers/net/usb/hso.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 5fb36ed..86292e6 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c@@ -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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1.7.9.5