bridge: netfilter: fix information leak

Struct tmp is copied from userspace.  It is not checked whether the "name"
field is NULL terminated.  This may lead to buffer overflow and passing
contents of kernel stack as a module name to try_then_request_module() and,
consequently, to modprobe commandline.  It would be seen by all userspace
processes.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
static int ebt_standard_compat_to_user(void __user *dst, const void *src)
{
	compat_int_t cv = *(int *)src;

	if (cv >= 0)
		cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
	return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
}

static int ebt_standard_compat_to_user(void __user *dst, const void *src)
{
	compat_int_t cv = *(int *)src;

	if (cv >= 0)
		cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv);
	return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
}
