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5d124e99c2
This patch fixes copy_namespaces()'s error path. when new nsproxy (new_ns) is created pointers to namespaces (ipc, uts) are copied from the old nsproxy. Later in copy_utsname, copy_ipcs, etc. according namespaces are get-ed. On error path needed namespaces are put-ed, so there's no need to put new nsproxy itelf as it woud cause putting namespaces for the second time. Found when incorporating namespaces into OpenVZ kernel. Signed-off-by: Pavel Emelianov <xemul@openvz.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
140 lines
2.7 KiB
C
140 lines
2.7 KiB
C
/*
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* Copyright (C) 2006 IBM Corporation
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*
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* Author: Serge Hallyn <serue@us.ibm.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*
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* Jun 2006 - namespaces support
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* OpenVZ, SWsoft Inc.
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* Pavel Emelianov <xemul@openvz.org>
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*/
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#include <linux/module.h>
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#include <linux/version.h>
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#include <linux/nsproxy.h>
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#include <linux/init_task.h>
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#include <linux/namespace.h>
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#include <linux/utsname.h>
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struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
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static inline void get_nsproxy(struct nsproxy *ns)
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{
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atomic_inc(&ns->count);
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}
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void get_task_namespaces(struct task_struct *tsk)
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{
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struct nsproxy *ns = tsk->nsproxy;
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if (ns) {
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get_nsproxy(ns);
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}
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}
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/*
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* creates a copy of "orig" with refcount 1.
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* This does not grab references to the contained namespaces,
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* so that needs to be done by dup_namespaces.
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*/
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static inline struct nsproxy *clone_namespaces(struct nsproxy *orig)
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{
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struct nsproxy *ns;
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ns = kmalloc(sizeof(struct nsproxy), GFP_KERNEL);
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if (ns) {
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memcpy(ns, orig, sizeof(struct nsproxy));
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atomic_set(&ns->count, 1);
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}
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return ns;
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}
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/*
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* copies the nsproxy, setting refcount to 1, and grabbing a
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* reference to all contained namespaces. Called from
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* sys_unshare()
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*/
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struct nsproxy *dup_namespaces(struct nsproxy *orig)
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{
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struct nsproxy *ns = clone_namespaces(orig);
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if (ns) {
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if (ns->namespace)
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get_namespace(ns->namespace);
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if (ns->uts_ns)
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get_uts_ns(ns->uts_ns);
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if (ns->ipc_ns)
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get_ipc_ns(ns->ipc_ns);
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}
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return ns;
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}
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/*
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* called from clone. This now handles copy for nsproxy and all
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* namespaces therein.
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*/
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int copy_namespaces(int flags, struct task_struct *tsk)
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{
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struct nsproxy *old_ns = tsk->nsproxy;
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struct nsproxy *new_ns;
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int err = 0;
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if (!old_ns)
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return 0;
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get_nsproxy(old_ns);
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if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC)))
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return 0;
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new_ns = clone_namespaces(old_ns);
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if (!new_ns) {
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err = -ENOMEM;
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goto out;
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}
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tsk->nsproxy = new_ns;
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err = copy_namespace(flags, tsk);
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if (err)
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goto out_ns;
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err = copy_utsname(flags, tsk);
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if (err)
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goto out_uts;
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err = copy_ipcs(flags, tsk);
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if (err)
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goto out_ipc;
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out:
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put_nsproxy(old_ns);
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return err;
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out_ipc:
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if (new_ns->uts_ns)
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put_uts_ns(new_ns->uts_ns);
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out_uts:
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if (new_ns->namespace)
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put_namespace(new_ns->namespace);
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out_ns:
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tsk->nsproxy = old_ns;
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kfree(new_ns);
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goto out;
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}
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void free_nsproxy(struct nsproxy *ns)
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{
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if (ns->namespace)
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put_namespace(ns->namespace);
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if (ns->uts_ns)
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put_uts_ns(ns->uts_ns);
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if (ns->ipc_ns)
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put_ipc_ns(ns->ipc_ns);
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kfree(ns);
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}
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