Re: [PATCH net] net: memcontrol: charge allocated memory after mem_cgroup_sk_alloc()

On Thu, Feb 01, 2018 at 10:16:55AM -0500, David Miller wrote:

From: Roman Gushchin <redacted>
Date: Wed, 31 Jan 2018 21:54:08 +0000

quoted

So I really start thinking that reverting 9f1c2674b328
("net: memcontrol: defer call to mem_cgroup_sk_alloc()")
and fixing the original issue differently might be easier
and a proper way to go. Does it makes sense?

You'll need to work that out with Eric Dumazet who added the
change in question which you think we should revert.

Eric,

can you, please, provide some details about the use-after-free problem
that you've fixed with commit 9f1c2674b328 ("net: memcontrol: defer call
to mem_cgroup_sk_alloc()" ? Do you know how to reproduce it?

Deferring mem_cgroup_sk_alloc() breaks socket memory accounting
and makes it much more fragile in general. So, I wonder, if there are
solutions for the use-after-free problem.

Thank you!

Roman