From: Florian Westphal <fw@strlen.de>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: netdev@vger.kernel.org, fw@strlen.de,
netfilter-devel@vger.kernel.org,
syzbot+adf6c6c2be1c3a718121@syzkaller.appspotmail.com,
Pablo Neira Ayuso <pablo@netfilter.org>,
Jozsef Kadlecsik <kadlec@netfilter.org>
Subject: Re: [Patch nf v2 1/3] xt_hashlimit: avoid OOM for user-controlled vmalloc
Date: Mon, 3 Feb 2020 13:16:12 +0100 [thread overview]
Message-ID: <20200203121612.GR795@breakpoint.cc> (raw)
In-Reply-To: <20200203043053.19192-2-xiyou.wangcong@gmail.com>
Cong Wang <xiyou.wangcong@gmail.com> 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.
>
> Reported-and-tested-by: syzbot+adf6c6c2be1c3a718121@syzkaller.appspotmail.com
> Cc: Pablo Neira Ayuso <pablo@netfilter.org>
> Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
> Cc: Florian Westphal <fw@strlen.de>
> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
> ---
> net/netfilter/xt_hashlimit.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
> index bccd47cd7190..5d9943b37c42 100644
> --- a/net/netfilter/xt_hashlimit.c
> +++ b/net/netfilter/xt_hashlimit.c
> @@ -293,8 +293,8 @@ static int htable_create(struct net *net, struct hashlimit_cfg3 *cfg,
> if (size < 16)
> size = 16;
> }
> - /* FIXME: don't use vmalloc() here or anywhere else -HW */
> - hinfo = vmalloc(struct_size(hinfo, hash, size));
> + hinfo = __vmalloc(struct_size(hinfo, hash, size),
> + GFP_USER | __GFP_NOWARN | __GFP_NORETRY, PAGE_KERNEL);
Sorry for not noticing this earlier: should that be GFP_KERNEL_ACCOUNT
instead of GFP_USER?
next prev parent reply other threads:[~2020-02-03 12:16 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-03 4:30 [Patch nf v2 0/3] netfilter: xt_hashlimit: a few improvements Cong Wang
2020-02-03 4:30 ` [Patch nf v2 1/3] xt_hashlimit: avoid OOM for user-controlled vmalloc Cong Wang
2020-02-03 12:16 ` Florian Westphal [this message]
2020-02-03 18:54 ` Cong Wang
2020-02-03 20:18 ` Florian Westphal
2020-02-07 14:57 ` Pablo Neira Ayuso
2020-02-03 4:30 ` [Patch nf v2 2/3] xt_hashlimit: reduce hashlimit_mutex scope for htable_put() Cong Wang
2020-02-07 14:54 ` Pablo Neira Ayuso
2020-02-03 4:30 ` [Patch nf v2 3/3] xt_hashlimit: limit the max size of hashtable Cong Wang
2020-02-03 12:06 ` Florian Westphal
2020-02-07 14:56 ` Pablo Neira Ayuso
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