Commit cb84f568 authored Sep 30, 2017 by Dan Carpenter Committed by Felipe Balbi Oct 11, 2017

usb: misc: usbtest: Fix overflow in usbtest_do_ioctl()



There used to be a test against "if (param->sglen > MAX_SGLEN)" but it
was removed during a refactor.  It leads to an integer overflow and a
stack overflow in test_queue() if we try to create a too large urbs[]
array on the stack.

There is a second integer overflow in test_queue() as well if
"param->iterations" is too high.  I don't immediately see that it's
harmful but I've added a check to prevent it and silence the static
checker warning.

Fixes: 18fc4ebd ("usb: misc: usbtest: Remove timeval usage")
Acked-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

parent 29c7f3e6

drivers/usb/misc/usbtest.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -1964,6 +1964,9 @@ test_queue(struct usbtest_dev dev, struct usbtest_param_32 param,
		int status = 0;
		struct urb *urbs[param->sglen];

		if (!param->sglen \|\| param->iterations > UINT_MAX / param->sglen)
		return -EINVAL;

		memset(&context, 0, sizeof(context));
		context.count = param->iterations * param->sglen;
		context.dev = dev;
		@@ -2087,6 +2090,8 @@ usbtest_do_ioctl(struct usb_interface intf, struct usbtest_param_32 param)

		if (param->iterations <= 0)
		return -EINVAL;
		if (param->sglen > MAX_SGLEN)
		return -EINVAL;
		/*
		* Just a bunch of test cases that every HCD is expected to handle.
		*