Re: [PATCH v2] aoe: fix the potential use-after-free problem in more places

[Valentin Kleibel]

Hi Joey,

> > We've tested your patch on our servers and ran into an issue.
> > With heavy I/O load the aoe device had stale I/Os (e.g. rsync waiting
> > indefinetly on one core) that can be "fixed" by running aoe-revalidate on
> > that device.
[...]> For the reference count debugging, I have sent a patch series here:
> [RFC PATCH 0/2] tracking the references of net_device in aoe
> https://lore.kernel.org/lkml/20241002040616.25193-1-jlee@xxxxxxxx/T/#t
>
> Base on my testing, the number of dev_hold(nd) and dev_put(nd) are balance
> in aoe after the this 'aoe: fix the potential use-after-free problem in more places'
> patch be applied on v6.11 kernel. I have tested add/modify/delete files in remote
> target by aoe. My testing is not a heavy I/O testing. But the result is
> balance.
>
> Could you please help to try the above debug patch series for looking at the
> refcnt value in aoe in your side?

Thanks for your work, i can confirm refcnt value is balanced and the 
issue is fixed now.

However, the I/O waiting issue reported before is still there, and 
occurs more often now.
This problem started with the first patch CVE-2023-6270 applied in 
commit f98364e92662.
This only happens with heavy I/O on our "older" storage systems with 
spinning disks. Unfortunately we do not know how we could debug this, 
have you got any hints what we could do?

Thanks,
Valentin

PS: sorry for the delay, I'm now back from a long vacation