lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Wed, 26 Feb 2020 11:07:49 -0800 (PST)
From:   David Miller <davem@...emloft.net>
To:     shakeelb@...gle.com
Cc:     edumazet@...gle.com, guro@...com, hannes@...xchg.org,
        tj@...nel.org, gthelen@...gle.com, mhocko@...nel.org,
        vdavydov.dev@...il.com, akpm@...ux-foundation.org,
        cgroups@...r.kernel.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [PATCH v3] cgroup: memcg: net: do not associate sock with
 unrelated cgroup

From: Shakeel Butt <shakeelb@...gle.com>
Date: Thu, 20 Feb 2020 17:46:04 -0800

> We are testing network memory accounting in our setup and noticed
> inconsistent network memory usage and often unrelated cgroups network
> usage correlates with testing workload. On further inspection, it
> seems like mem_cgroup_sk_alloc() and cgroup_sk_alloc() are broken in
> IRQ context specially for cgroup v1.
> 
> mem_cgroup_sk_alloc() and cgroup_sk_alloc() can be called in IRQ context
> and kind of assumes that this can only happen from sk_clone_lock()
> and the source sock object has already associated cgroup. However in
> cgroup v1, where network memory accounting is opt-in, the source sock
> can be unassociated with any cgroup and the new cloned sock can get
> associated with unrelated interrupted cgroup.
> 
> Cgroup v2 can also suffer if the source sock object was created by
> process in the root cgroup or if sk_alloc() is called in IRQ context.
> The fix is to just do nothing in interrupt.
> 
> WARNING: Please note that about half of the TCP sockets are allocated
> from the IRQ context, so, memory used by such sockets will not be
> accouted by the memcg.

Then if we do this then we have to have some kind of subsequent change
to attach these sockets to the correct cgroup, right?

Powered by blists - more mailing lists