Linux kernel maintainer Greg Kroah-Hartman and several other senior Linux figures have published a “Linux Kernel Community Enforcement Statement” to be included in future Linux documentation, in order to ensure contributions to the kernel don't fall foul of copyright claims that have already seen a single developer win "at least a few million Euros.”
In a post released on Monday, October 16th, Kroah-Hartman explained the Statement's needed because not everyone who contributes to the kernel understands the obligations the GNU Public Licence 2.0 (GPL 2.0), and the licence has “ambiguities … that no one in our community has ever considered part of compliance.”
Those ambiguities, he writes, have been used by a developer named Patrick McHardy to run multiple copyright enforcement lawsuits.
McHardy is a former contributor to a project called Netfilter that brings useful networking functionality such as network address translation to Linux. However the project suspended him from its core team in 2016 over “license enforcement activities” that contravened the project's own policies. He's also been criticised by the Software Freedom Conservancy for “prioritizing financial gain over compliance.”
Lawyer Heather Meeker believes that McHardy wrote “well under .25% of the code in the kernel” but has parlayed that into around 50 copyright complaints about Linux companies' use of Netfilter. Most of his actions take place in Germany, where local law makes such claims easier to mount.
Kroah-Hartman says “It is not possible to know an exact figure due to the secrecy of Patrick’s actions, but we are aware of activity that has resulted in payments of at least a few million Euros. We are also aware that these actions, which have continued for at least four years, have threatened the confidence in our ecosystem.”
To restore that confidence, the Statement “adopts the same termination provisions we are all familiar with from GPL-3.0 as an Additional Permission giving companies confidence that they will have time to come into compliance if a failure is identified.”
Those provisions are:
However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation.
Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice.
“Their ability to rely on this Additional Permission will hopefully re-establish user confidence and help direct enforcement activity back to the original purpose we have all sought over the years – actual compliance”, say Kroah-Hartman and his co-authors wrote.
The Register has approached McHardy for comment, but as he's reportedly a reluctant correspondent when asked about his legal activities we don't hold out much hope of a reply. If he does respond, we'll either update this story or write a new one.
If you've received a demand from McHardy, Netfilter recommends taking it seriously and ensuring compliance with the GPL. ®