linux-kernel - Re: [PATCH memcg v6] net: set proper memcg for net

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]

Message-ID: <CALvZod7+tpgKSQpMAgNKDtcsimcSjoh4rbKmUsy3G=QcRHci+Q@mail.gmail.com>
Date:   Mon, 6 Jun 2022 22:58:45 -0700
From:   Shakeel Butt <shakeelb@...gle.com>
To:     Vasily Averin <vvs@...nvz.org>
Cc:     Qian Cai <quic_qiancai@...cinc.com>,
        Roman Gushchin <roman.gushchin@...ux.dev>,
        Andrew Morton <akpm@...ux-foundation.org>, kernel@...nvz.org,
        LKML <linux-kernel@...r.kernel.org>,
        Linux MM <linux-mm@...ck.org>,
        Michal Koutný <mkoutny@...e.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Michal Hocko <mhocko@...e.com>,
        Florian Westphal <fw@...len.de>,
        "David S. Miller" <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        Paolo Abeni <pabeni@...hat.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Cgroups <cgroups@...r.kernel.org>
Subject: Re: [PATCH memcg v6] net: set proper memcg for net_init hooks allocations

On Mon, Jun 6, 2022 at 11:45 AM Vasily Averin <vvs@...nvz.org> wrote:
>
[...]
>
> As far as I understand this report means that 'init_net' have incorrect
> virtual address on arm64.

So, the two call stacks tell the addresses belong to the kernel
modules (nfnetlink and nf_tables) whose underlying memory is allocated
through vmalloc and virt_to_page() does not work on vmalloc()
addresses.

>
> Roman, Shakeel, I need your help
>
> Should we perhaps verify kaddr via virt_addr_valid() before using virt_to_page()
> If so, where it should be checked?

I think virt_addr_valid() check in mem_cgroup_from_obj() should work
but I think it is expensive on the arm64 platform. The cheaper and a
bit hacky way to avoid such addresses is to directly use
is_vmalloc_addr() directly.