> I also fear about what Oracle could do, as they are copyright holders of parts of Linux
They have already published commits to Linux under the GPL, they cannot just "take it back". The worst Oracle does is stop contributing to the kernel, which they rarely do to begin with. The "worst" Oracle can do is sue third parties that violate the GPL on their part of the kernel - which would predominantly be proprietary vendors.
They are also the copyright holder of a huge chunk of ZFS' code. So they can also sue Canonical over their violation of the CDDL which oracle (as the copyright holder) has licensed ZFS under.
Can you point to the area in which Canonical is in violation of the CDDL? I can't see that they are. They may be in violation of the GPL, but the CDDL seems fine. Specifically[0]:
"1.3. Covered Software means (a) the Original Software, or (b) Modifications, or (c) the combination of files containing Original Software with files containing Modifications, in each case including portions thereof."
"Any Covered Software that You distribute or otherwise make available in Executable form must also be made available in Source Code form and that Source Code form must be distributed only under the terms of this License."
The binary module they are distributing is the 'covered software' and they are making the source code and their modifications to that source code available via CDDL. They appear to be meeting their CDDL license burden.
In other words, Linux Kernel developers could sue because the GPL license terms aren't met, but Oracle couldn't sue because the CDDL license terms are being met.
n other words, Linux Kernel developers could sue because the GPL license terms aren't met, but Oracle couldn't sue because the CDDL license terms are being met.
As Oracle has contributed to the Linux kernel as well, they are in a position to sue over GPL violation.
Indeed, but generally people seem to be coming at it from the Oracle suing over the CDDL side.
Additionally, if I understand correctly, in order to have a chance to sue, Oracle would have to show that the code in question violates their actual copyright, which is only in code that the wrote/contributed. So Oracle would likely need to prove that the ZFS code interfaces/touches/uses their copyrighted code, otherwise they would not have standing (in the US). I have no clue if that interaction occurs or not.
They have already published commits to Linux under the GPL, they cannot just "take it back". The worst Oracle does is stop contributing to the kernel, which they rarely do to begin with. The "worst" Oracle can do is sue third parties that violate the GPL on their part of the kernel - which would predominantly be proprietary vendors.