[lvc-project] [PATCH 6.1 14/29] xfs: use xfs_defer_pending objects to recover intent items

[Leah Rumancik]

Okay so a summary from my understanding, correct me if I'm wrong:

03f7767c9f612 introduced the issue in both 6.1 and 6.6.

On mainline, this is resolved by e5f1a5146ec3. This commit is painful
to apply to 6.1 but does apply to 6.6 along with the rest of the
patchset it was a part of (which is the set you just sent out for
6.6).

With the stable branches we try to balance the risk of introducing new
bugs via huge fixes with the benefit of the fix itself. Especially if
the patches don't apply cleanly, it might not be worth the risk and
effort to do the porting. Hmm, since it seems like we might not even
end up taking 03f7767c9f6120 to stable, I'd propose we just drop
03f7767c9f6120 for now. If the rest of the subsequent patches in the
original set apply cleanly, I don't think we need to drop them all. We
can then try to fix the UAF with a more targeted approach in a later
patch instead of via direct cherry-picks.

 What do you think?

- leah


>
> >
> > Also, the backport set you mentioned was based on a set from 6.6.y. I
> > don't see the suggested fix (e5f1a5146ec3) there either. If it's not
> > too much hassle, could you see if we have the same problem for 6.6.y
> > as well?
>
> Yes, the crash occurs there, too. And for 6.6 case it actually is for a
> released kernel (since v6.6.24).
>
> The remaining four patches of the original upstream series [1] - one of
> which is e5f1a5146ec3 - can be applied there without many problems,
> fortunately.
>
> I'll send them to you in a separate thread.