netdev - Re: [Patch nf v2 1/3] xt_hashlimit: avoid OOM for user-controlled vmalloc

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Message-ID: <20200207145734.qhy53bxrqocvjb2d@salvia>
Date:   Fri, 7 Feb 2020 15:57:34 +0100
From:   Pablo Neira Ayuso <pablo@...filter.org>
To:     Cong Wang <xiyou.wangcong@...il.com>
Cc:     netdev@...r.kernel.org, fw@...len.de,
        netfilter-devel@...r.kernel.org,
        syzbot+adf6c6c2be1c3a718121@...kaller.appspotmail.com,
        Jozsef Kadlecsik <kadlec@...filter.org>
Subject: Re: [Patch nf v2 1/3] xt_hashlimit: avoid OOM for user-controlled
 vmalloc

On Sun, Feb 02, 2020 at 08:30:51PM -0800, Cong Wang wrote:
> The hashtable size could be controlled by user, so use flags
> GFP_USER | __GFP_NOWARN to avoid OOM warning triggered by user-space.
> 
> Also add __GFP_NORETRY to avoid retrying, as this is just a
> best effort and the failure is already handled gracefully.

I think OOM is unlikely to happen now that cfg->size is capped in
your patch 3/3.