[PATCH 1/1] veth: don't free priv->status until dev->destructor(v2)

[Serge E. Hallyn]

Based on the commit msg on ae0e8e82205c903978a79ebf5e31c670b61fa5b4, it looks
like oopses were caused when people were reading the veth dev stats while the
module was being unloaded, causing a deref of freed memory in veth_get_stats()?
If so, I believe the following patch (still against mainline, so not on top of
my previous patch or on top of a git-revert of
ae0e8e82205c903978a79ebf5e31c670b61fa5b)) should prevent that.  All the stats
are gathered within one rcu cycle, while the device free hook first sets the
device stats struct to NULL, waits an rcu cycle before freeing it.

I haven't been able to reproduce the original oops though (been trying
to cat the stats sysfs files while rmmoding veth, to no avail, and haven't
found an original bug report or testcase), so can't verify whether this patch
prevents the original oops.

Does this look sufficient?

thanks,
-serge