Re: [PATCH] drivers/char/mem.c: Add /dev/ioports, supporting 16-bit and 32-bit ports

[Arnd Bergmann]

On Friday 09 May 2014 12:19:16 Josh Triplett wrote:

> +	if (!access_ok(VERIFY_WRITE, buf, count))
> +		return -EFAULT;
> +	if (port > 65535)
> +		return 0;

This should probably test against IO_SPACE_LIMIT, which may be zero,
something larger than 65536 or even ULONG_MAX, depending on the
architecture.

In cases where this IO_SPACE_LIMIT is zero or ULONG_MAX, we should
probably disallow access completely. The former case is for architectures
that don't have any I/O ports, the other is either a mistake, or is
used when inb is defined as readb, and the port numbers are just virtual
addresses.

	Arnd
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/