Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
From:   "Eric W. Biederman" <ebiederm@xmission.com>
To:     Alexey Gladkov <legion@kernel.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Christian Brauner <christian.brauner@ubuntu.com>,
        Daniel Walsh <dwalsh@redhat.com>,
        Davidlohr Bueso <dbueso@suse.de>,
        Kirill Tkhai <ktkhai@virtuozzo.com>,
        Linux Containers <containers@lists.linux.dev>,
        Manfred Spraul <manfred@colorfullife.com>,
        Serge Hallyn <serge@hallyn.com>,
        Varad Gautam <varad.gautam@suse.com>,
        Vasily Averin <vvs@virtuozzo.com>
References: <CAHk-=wgBB8iPd0W=MQWnQJukMAPAqgsC0QX2wwiSvcct9zu_RA@mail.gmail.com>
        <cover.1650631347.git.legion@kernel.org>
        <32a29b3eb5f560e30ef24cfb86e480684b49ac62.1650631347.git.legion@kernel.org>
Date:   Mon, 02 May 2022 11:09:22 -0500
In-Reply-To: <32a29b3eb5f560e30ef24cfb86e480684b49ac62.1650631347.git.legion@kernel.org>
        (Alexey Gladkov's message of "Fri, 22 Apr 2022 14:53:38 +0200")
Message-ID: <87sfprudal.fsf@email.froward.int.ebiederm.org>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain
Subject: Re: [PATCH v1 2/4] ipc: Use proper ipc namespace
Precedence: bulk

Alexey Gladkov <legion@kernel.org> writes:

> As Eric Biederman pointed out, changing the namespace broke checkpoint
> restore. I have reverted my previous changes.

Can you remind me the bug that is being fixed here?

I am probably just going to fast to see it, but it would be good to have
it described in the commit comment.

Thanks,
Eric

>
> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
> Signed-off-by: Alexey Gladkov <legion@kernel.org>
> ---
>  ipc/ipc_sysctl.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
>
> diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
> index eb7ba8e0a355..ff99d0305a5b 100644
> --- a/ipc/ipc_sysctl.c
> +++ b/ipc/ipc_sysctl.c
> @@ -72,7 +72,7 @@ static int proc_ipc_sem_dointvec(struct ctl_table *table, int write,
>  static int proc_ipc_dointvec_minmax_checkpoint_restore(struct ctl_table *table,
>  		int write, void *buffer, size_t *lenp, loff_t *ppos)
>  {
> -	struct ipc_namespace *ns = table->extra1;
> +	struct ipc_namespace *ns = current->nsproxy->ipc_ns;
>  	struct ctl_table ipc_table;
>  
>  	if (write && !checkpoint_restore_ns_capable(ns->user_ns))
> @@ -244,15 +244,12 @@ bool setup_ipc_sysctls(struct ipc_namespace *ns)
>  #ifdef CONFIG_CHECKPOINT_RESTORE
>  			} else if (tbl[i].data == &init_ipc_ns.ids[IPC_SEM_IDS].next_id) {
>  				tbl[i].data = &ns->ids[IPC_SEM_IDS].next_id;
> -				tbl[i].extra1 = ns;
>  
>  			} else if (tbl[i].data == &init_ipc_ns.ids[IPC_MSG_IDS].next_id) {
>  				tbl[i].data = &ns->ids[IPC_MSG_IDS].next_id;
> -				tbl[i].extra1 = ns;
>  
>  			} else if (tbl[i].data == &init_ipc_ns.ids[IPC_SHM_IDS].next_id) {
>  				tbl[i].data = &ns->ids[IPC_SHM_IDS].next_id;
> -				tbl[i].extra1 = ns;
>  #endif
>  			} else {
>  				tbl[i].data = NULL;