Comment 7 for bug 1775165

Hi Po-Hsu Lin,

Sorry for not updating this bug earlier.

Upstream 4.4 and 4.9 are also effected by this bug, so I went and posted the
patches to be considered for upstream -stable.

Upstream 4.4 thread: [1]
Upstream 4.9 thread: [2]

Now, I got some feedback from the original author of the upstream commits that
the scenario is more complicated than I thought, and I ended up missing a lot
of commits required to fix the problem completely.

It turns out that the fixes prevent the system from crashing, but that some
data structures silently get corrupted over time, meaning the system will
eventually require a reboot anyway.

If you are interested, you can read all about it here: [3] [4] [5]

For now, it seems the list of commits required to actually fix the problem [6]
is a little too large to include in -stable, since it changes a lot of that
subsystem dramatically, and it might introduce regressions, which I want to
avoid.

In the end Greg K-H agreed with me [7], the patches were dropped, and this
won't be getting fixed upstream.

That is the status of this bug, and it likely won't be fixed. I did try, but
there is just too much code to backport and support, its easier to tell people
to use HWE kernels if they are hitting the problem.

[1] https://www.spinics.net/lists/stable/msg296857.html
[2] https://www.spinics.net/lists/stable/msg296895.html
[3] https://www.spinics.net/lists/stable/msg296992.html
[4] https://www.spinics.net/lists/stable/msg297024.html
[5] https://www.spinics.net/lists/stable/msg297027.html
[6] https://www.spinics.net/lists/stable/msg297476.html
[7] https://www.spinics.net/lists/stable/msg297485.html