Re: [PATCH iproute2] iplink: work around rtattr length limits for IFLA_VFINFO_LIST

On 1/16/21 6:21 PM, Jakub Kicinski wrote:

I wonder. There is something inherently risky about making
a precedent for user space depending on invalid kernel output.

_If_ we want to fix the kernel, IMO we should only fix the kernel.

IMHO this is a kernel bug that should be fixed. An easy fix to check the
overflow in nla_nest_end and return an error. Sadly, nla_nest_end return
code is ignored and backporting any change to fix that will be
nightmare. A warning will identify places that need to be fixed.

We can at least catch and fix this overflow which is by far the primary
known victim of the rollover.