c197d63627
Fix nla_policy definition by specifying an exact length type attribute
to CTINFO action paraneter block structure. Without this change,
netlink parsing will fail validation and the action will not be
instantiated.
8cb081746c03 ("netlink: make validation more configurable for future")
introduced much stricter checking to attributes being passed via
netlink. Existing actions were updated to use less restrictive
deprecated versions of nla_parse_nested.
As a new module, act_ctinfo should be designed to use the strict
checking model otherwise, well, what was the point of implementing it.
Confession time: Until very recently, development of this module has
been done on 'net-next' tree to 'clean compile' level with run-time
testing on backports to 4.14 & 4.19 kernels under openwrt. This is how
I managed to miss the run-time impacts of the new strict
nla_parse_nested function. I hopefully have learned something from this
(glances toward laptop running a net-next kernel)
There is however a still outstanding implication on iproute2 user space
in that it needs to be told to pass nested netlink messages with the
nested attribute actually set. So even with this kernel fix to do
things correctly you still cannot instantiate a new 'strict'
nla_parse_nested based action such as act_ctinfo with iproute2's tc.
Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.