From: Julian Anastasov <ja@ssi.bg>
To: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Cc: horms@verge.net.au, netdev@vger.kernel.org,
lvs-devel@vger.kernel.org, netfilter-devel@vger.kernel.org,
linux-kernel@vger.kernel.org,
"Stéphane Graber" <stgraber@stgraber.org>,
"Christian Brauner" <brauner@kernel.org>,
"Pablo Neira Ayuso" <pablo@netfilter.org>,
"Jozsef Kadlecsik" <kadlec@netfilter.org>,
"Florian Westphal" <fw@strlen.de>
Subject: Re: [PATCH net-next v3 2/2] ipvs: allow some sysctls in non-init user namespaces
Date: Fri, 3 May 2024 16:06:24 +0300 (EEST) [thread overview]
Message-ID: <8e70d6d3-6852-7b84-81b3-5d1a798f224f@ssi.bg> (raw)
In-Reply-To: <20240418145743.248109-2-aleksandr.mikhalitsyn@canonical.com>
[-- Attachment #1: Type: text/plain, Size: 2329 bytes --]
Hello,
On Thu, 18 Apr 2024, Alexander Mikhalitsyn wrote:
> Let's make all IPVS sysctls writtable even when
> network namespace is owned by non-initial user namespace.
>
> Let's make a few sysctls to be read-only for non-privileged users:
> - sync_qlen_max
> - sync_sock_size
> - run_estimation
> - est_cpulist
> - est_nice
>
> I'm trying to be conservative with this to prevent
> introducing any security issues in there. Maybe,
> we can allow more sysctls to be writable, but let's
> do this on-demand and when we see real use-case.
>
> This patch is motivated by user request in the LXC
> project [1]. Having this can help with running some
> Kubernetes [2] or Docker Swarm [3] workloads inside the system
> containers.
>
> Link: https://github.com/lxc/lxc/issues/4278 [1]
> Link: https://github.com/kubernetes/kubernetes/blob/b722d017a34b300a2284b890448e5a605f21d01e/pkg/proxy/ipvs/proxier.go#L103 [2]
> Link: https://github.com/moby/libnetwork/blob/3797618f9a38372e8107d8c06f6ae199e1133ae8/osl/namespace_linux.go#L682 [3]
>
> Cc: Stéphane Graber <stgraber@stgraber.org>
> Cc: Christian Brauner <brauner@kernel.org>
> Cc: Julian Anastasov <ja@ssi.bg>
> Cc: Simon Horman <horms@verge.net.au>
> Cc: Pablo Neira Ayuso <pablo@netfilter.org>
> Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
> Cc: Florian Westphal <fw@strlen.de>
> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
> ---
> net/netfilter/ipvs/ip_vs_ctl.c | 21 +++++++++++++++------
> 1 file changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
> index 32be24f0d4e4..c3ba71aa2654 100644
> --- a/net/netfilter/ipvs/ip_vs_ctl.c
> +++ b/net/netfilter/ipvs/ip_vs_ctl.c
...
> @@ -4284,12 +4285,6 @@ static int __net_init ip_vs_control_net_init_sysctl(struct netns_ipvs *ipvs)
> tbl = kmemdup(vs_vars, sizeof(vs_vars), GFP_KERNEL);
> if (tbl == NULL)
> return -ENOMEM;
> -
> - /* Don't export sysctls to unprivileged users */
> - if (net->user_ns != &init_user_ns) {
> - tbl[0].procname = NULL;
> - ctl_table_size = 0;
> - }
> } else
> tbl = vs_vars;
> /* Initialize sysctl defaults */
Sorry but you have to send v4 because above if-block was
changed with net-next commit 635470eb0aa7 from today...
Regards
--
Julian Anastasov <ja@ssi.bg>
next prev parent reply other threads:[~2024-05-03 13:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-18 14:57 [PATCH net-next v3 1/2] ipvs: add READ_ONCE barrier for ipvs->sysctl_amemthresh Alexander Mikhalitsyn
2024-04-18 14:57 ` [PATCH net-next v3 2/2] ipvs: allow some sysctls in non-init user namespaces Alexander Mikhalitsyn
2024-04-21 11:06 ` Julian Anastasov
2024-05-03 13:06 ` Julian Anastasov [this message]
2024-05-06 14:17 ` Aleksandr Mikhalitsyn
2024-04-21 11:06 ` [PATCH net-next v3 1/2] ipvs: add READ_ONCE barrier for ipvs->sysctl_amemthresh Julian Anastasov
2024-04-22 7:34 ` Aleksandr Mikhalitsyn
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