From: ebiederm@xmission•com (Eric W. Biederman)
To: Andy Lutomirski <luto@amacapital•net>
Cc: security@kernel•org, linux-kernel@vger•kernel.org,
netdev@vger•kernel.org
Subject: Re: [PATCH 2/2] Rename nsproxy.pid_ns to nsproxy.pid_ns_for_children
Date: Mon, 26 Aug 2013 18:02:42 -0700 [thread overview]
Message-ID: <87y57olzd9.fsf@xmission.com> (raw)
In-Reply-To: <a5db0606160dbd1412828be0d91a4a115a84abf6.1377196394.git.luto@amacapital.net> (Andy Lutomirski's message of "Thu, 22 Aug 2013 11:39:16 -0700")
Andy Lutomirski <luto@amacapital•net> writes:
> nsproxy.pid_ns is *not* the task's pid namespace. The name should clarify
> that.
>
> This makes it more obvious that setns on a pid namespace is weird --
> it won't change the pid namespace shown in procfs.
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission•com>
> Signed-off-by: Andy Lutomirski <luto@amacapital•net>
> ---
> include/linux/nsproxy.h | 6 +++++-
> kernel/fork.c | 5 +++--
> kernel/nsproxy.c | 27 ++++++++++++++-------------
> kernel/pid_namespace.c | 4 ++--
> 4 files changed, 24 insertions(+), 18 deletions(-)
>
> diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h
> index 10e5947..b4ec59d 100644
> --- a/include/linux/nsproxy.h
> +++ b/include/linux/nsproxy.h
> @@ -14,6 +14,10 @@ struct fs_struct;
> * A structure to contain pointers to all per-process
> * namespaces - fs (mount), uts, network, sysvipc, etc.
> *
> + * The pid namespace is an exception -- it's accessed using
> + * task_active_pid_ns. The pid namespace here is the
> + * namespace that children will use.
> + *
> * 'count' is the number of tasks holding a reference.
> * The count for each namespace, then, will be the number
> * of nsproxies pointing to it, not the number of tasks.
> @@ -27,7 +31,7 @@ struct nsproxy {
> struct uts_namespace *uts_ns;
> struct ipc_namespace *ipc_ns;
> struct mnt_namespace *mnt_ns;
> - struct pid_namespace *pid_ns;
> + struct pid_namespace *pid_ns_for_children;
> struct net *net_ns;
> };
> extern struct nsproxy init_nsproxy;
> diff --git a/kernel/fork.c b/kernel/fork.c
> index e23bb19..bf46287 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1177,7 +1177,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
> * don't allow the creation of threads.
> */
> if ((clone_flags & (CLONE_VM|CLONE_NEWPID)) &&
> - (task_active_pid_ns(current) != current->nsproxy->pid_ns))
> + (task_active_pid_ns(current) !=
> + current->nsproxy->pid_ns_for_children))
> return ERR_PTR(-EINVAL);
>
> retval = security_task_create(clone_flags);
> @@ -1351,7 +1352,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
>
> if (pid != &init_struct_pid) {
> retval = -ENOMEM;
> - pid = alloc_pid(p->nsproxy->pid_ns);
> + pid = alloc_pid(p->nsproxy->pid_ns_for_children);
> if (!pid)
> goto bad_fork_cleanup_io;
> }
> diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
> index 364ceab..997cbb9 100644
> --- a/kernel/nsproxy.c
> +++ b/kernel/nsproxy.c
> @@ -29,15 +29,15 @@
> static struct kmem_cache *nsproxy_cachep;
>
> struct nsproxy init_nsproxy = {
> - .count = ATOMIC_INIT(1),
> - .uts_ns = &init_uts_ns,
> + .count = ATOMIC_INIT(1),
> + .uts_ns = &init_uts_ns,
> #if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC)
> - .ipc_ns = &init_ipc_ns,
> + .ipc_ns = &init_ipc_ns,
> #endif
> - .mnt_ns = NULL,
> - .pid_ns = &init_pid_ns,
> + .mnt_ns = NULL,
> + .pid_ns_for_children = &init_pid_ns,
> #ifdef CONFIG_NET
> - .net_ns = &init_net,
> + .net_ns = &init_net,
> #endif
> };
>
> @@ -85,9 +85,10 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
> goto out_ipc;
> }
>
> - new_nsp->pid_ns = copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns);
> - if (IS_ERR(new_nsp->pid_ns)) {
> - err = PTR_ERR(new_nsp->pid_ns);
> + new_nsp->pid_ns_for_children =
> + copy_pid_ns(flags, user_ns, tsk->nsproxy->pid_ns_for_children);
> + if (IS_ERR(new_nsp->pid_ns_for_children)) {
> + err = PTR_ERR(new_nsp->pid_ns_for_children);
> goto out_pid;
> }
>
> @@ -100,8 +101,8 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
> return new_nsp;
>
> out_net:
> - if (new_nsp->pid_ns)
> - put_pid_ns(new_nsp->pid_ns);
> + if (new_nsp->pid_ns_for_children)
> + put_pid_ns(new_nsp->pid_ns_for_children);
> out_pid:
> if (new_nsp->ipc_ns)
> put_ipc_ns(new_nsp->ipc_ns);
> @@ -174,8 +175,8 @@ void free_nsproxy(struct nsproxy *ns)
> put_uts_ns(ns->uts_ns);
> if (ns->ipc_ns)
> put_ipc_ns(ns->ipc_ns);
> - if (ns->pid_ns)
> - put_pid_ns(ns->pid_ns);
> + if (ns->pid_ns_for_children)
> + put_pid_ns(ns->pid_ns_for_children);
> put_net(ns->net_ns);
> kmem_cache_free(nsproxy_cachep, ns);
> }
> diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
> index 6917e8e..601bb36 100644
> --- a/kernel/pid_namespace.c
> +++ b/kernel/pid_namespace.c
> @@ -349,8 +349,8 @@ static int pidns_install(struct nsproxy *nsproxy, void *ns)
> if (ancestor != active)
> return -EINVAL;
>
> - put_pid_ns(nsproxy->pid_ns);
> - nsproxy->pid_ns = get_pid_ns(new);
> + put_pid_ns(nsproxy->pid_ns_for_children);
> + nsproxy->pid_ns_for_children = get_pid_ns(new);
> return 0;
> }
next prev parent reply other threads:[~2013-08-27 1:02 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-22 18:39 [PATCH 0/2] Rename nsproxy.pid_ns and fix a related security bug Andy Lutomirski
2013-08-22 18:39 ` [PATCH 1/2] net: Check the correct namespace when spoofing pid over SCM_RIGHTS Andy Lutomirski
2013-08-27 1:02 ` Eric W. Biederman
2013-08-22 18:39 ` [PATCH 2/2] Rename nsproxy.pid_ns to nsproxy.pid_ns_for_children Andy Lutomirski
2013-08-22 18:56 ` Oleg Nesterov
2013-08-27 1:02 ` Eric W. Biederman [this message]
2013-08-26 19:59 ` [PATCH 0/2] Rename nsproxy.pid_ns and fix a related security bug David Miller
2013-08-27 1:03 ` Eric W. Biederman
2013-08-27 17:53 ` David Miller
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