The group, Grsecurity which has filed the lawsuit under its trading name Open Source Security, sells its patch to subscribers and has taken offence at Bruce Perens' characterisation of its efforts as presenting "a contributory infringement and breach of contract risk".
Perens issued a statement on 28 June, detailing his reasons why users should avoid using the Grsecurity patch. "It (the patch) is a derivative work of the Linux kernel which touches the kernel internals in many different places. It is inseparable from Linux and cannot work without it," he wrote.
"It would fail a fair-use test (obviously, ask offline if you don’t understand). Because of its strongly derivative nature of the kernel, it must be under the GPL version 2 licence, or a license compatible with the GPL and with terms no more restrictive than the GPL. Earlier versions were distributed under GPL version 2."
Linux creator Linus Torvalds has, in the past, described the Grsecurity patch as "pure garbage".
Asked about how Grsecurity dealt with a particular issue, Torvalds responded: "Don't bother with Grsecurity. Their approach has always been 'we don't care if we break anything, we'll just claim it's because we're extra secure'.
"The thing is a joke, and they are clowns. When they started talking about people taking advantage of them, I stopped trying to be polite about their bullshit. Their patches are pure garbage."
In the lawsuit, Grsecurity argued that the subscription agreement gave it the right to terminate a client's subscription, thereby only limiting that person's access to future updates or versions (that is, patches that have not yet been developed, created, or released), if the patches are redistributed outside of the explicit obligations under the GPLv2 to the client’s customers.
"There is no explicit or implicit term, section, or clause in the GPLv2 that is applicable over future versions or updates of the Patches that have not yet been developed, created, or released by plaintiff," Grsecurity claimed.
"The subscription agreement does not apply further restrictions on a client’s ability to redistribute the patches in their possession, or restrict their ability to exercise their rights for patches in their possession, in accordance with the terms and conditions of the GPLv2."
In his post,Perens had written: "Grsecurity’s stable patch access agreement adds a term to the GPL prohibiting distribution or creating a penalty for distribution. GPL section 6 specifically prohibits any addition of terms. Thus, the GPL licence, which allows Grsecurity to create its derivative work of the Linux kernel, terminates, and the copyright of the Linux kernel is infringed."