Re: [PATCH V4 for-next 3/4] IB/core: Export ib_create/destroy_flow through uverbs

[Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>]

On Wed, Aug 28, 2013 at 03:47:54PM +0300, Matan Barak wrote:
> +
> +	if (cmd.comp_mask)
> +		return -EINVAL;

So, how do you propose to interoperate with new user space/old
kernels?

How will user space know what comp_mask values the kernel will
support?

The notion that was established in the verbs patches is that extra
structure fields are ignored by old software.

> +	if ((cmd.flow_attr.type == IB_FLOW_ATTR_SNIFFER &&
> +	     !capable(CAP_NET_ADMIN)) || !capable(CAP_NET_RAW))
> +		return -EPERM;
> +
> +	if (cmd.flow_attr.num_of_specs < 0 ||
> +	    cmd.flow_attr.num_of_specs > IB_FLOW_SPEC_SUPPORT_LAYERS)
> +		return -EINVAL;
> +
> +	kern_attr_size = cmd.flow_attr.size - sizeof(cmd) -
> +			 sizeof(struct ib_uverbs_cmd_hdr_ex);
> +
> +	if (cmd.flow_attr.size < 0 || cmd.flow_attr.size > in_len ||
> +	    kern_attr_size < 0 || kern_attr_size >
> +	    (cmd.flow_attr.num_of_specs * sizeof(struct ib_kern_spec)))
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Watch out for integer overflow here..

Jason
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