// SPDX-License-Identifier: GPL-2.0-only/* * Copyright (C) 2006 IBM Corporation * * Author: Serge Hallyn <serue@us.ibm.com> * * Jun 2006 - namespaces support * OpenVZ, SWsoft Inc. * Pavel Emelianov <xemul@openvz.org> */ #include <linux/slab.h>#include <linux/export.h>#include <linux/nsproxy.h>#include <linux/init_task.h>#include <linux/mnt_namespace.h>#include <linux/utsname.h>#include <linux/pid_namespace.h>#include <net/net_namespace.h>#include <linux/ipc_namespace.h>#include <linux/time_namespace.h>#include <linux/fs_struct.h>#include <linux/proc_fs.h>#include <linux/proc_ns.h>#include <linux/file.h>#include <linux/syscalls.h>#include <linux/cgroup.h>#include <linux/perf_event.h> static struct kmem_cache *nsproxy_cachep; struct nsproxy init_nsproxy = { .count = REFCOUNT_INIT(1), .uts_ns = &init_uts_ns,#if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC) .ipc_ns = &init_ipc_ns,#endif .mnt_ns = NULL, .pid_ns_for_children = &init_pid_ns,#ifdef CONFIG_NET .net_ns = &init_net,#endif#ifdef CONFIG_CGROUPS .cgroup_ns = &init_cgroup_ns,#endif#ifdef CONFIG_TIME_NS .time_ns = &init_time_ns, .time_ns_for_children = &init_time_ns,#endif}; static inline struct nsproxy *create_nsproxy(void){ struct nsproxy *nsproxy; nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL); if (nsproxy) refcount_set(&nsproxy->count, 1); return nsproxy;} /* * Create new nsproxy and all of its the associated namespaces. * Return the newly created nsproxy. Do not attach this to the task, * leave it to the caller to do proper locking and attach it to task. */static struct nsproxy *create_new_namespaces(unsigned long flags, struct task_struct *tsk, struct user_namespace *user_ns, struct fs_struct *new_fs){ struct nsproxy *new_nsp; int err; new_nsp = create_nsproxy(); if (!new_nsp) return ERR_PTR(-ENOMEM); new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, user_ns, new_fs); if (IS_ERR(new_nsp->mnt_ns)) { err = PTR_ERR(new_nsp->mnt_ns); goto out_ns; } new_nsp->uts_ns = copy_utsname(flags, user_ns, tsk->nsproxy->uts_ns); if (IS_ERR(new_nsp->uts_ns)) { err = PTR_ERR(new_nsp->uts_ns); goto out_uts; } new_nsp->ipc_ns = copy_ipcs(flags, user_ns, tsk->nsproxy->ipc_ns); if (IS_ERR(new_nsp->ipc_ns)) { err = PTR_ERR(new_nsp->ipc_ns); goto out_ipc; } 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; } new_nsp->cgroup_ns = copy_cgroup_ns(flags, user_ns, tsk->nsproxy->cgroup_ns); if (IS_ERR(new_nsp->cgroup_ns)) { err = PTR_ERR(new_nsp->cgroup_ns); goto out_cgroup; } new_nsp->net_ns = copy_net_ns(flags, user_ns, tsk->nsproxy->net_ns); if (IS_ERR(new_nsp->net_ns)) { err = PTR_ERR(new_nsp->net_ns); goto out_net; } new_nsp->time_ns_for_children = copy_time_ns(flags, user_ns, tsk->nsproxy->time_ns_for_children); if (IS_ERR(new_nsp->time_ns_for_children)) { err = PTR_ERR(new_nsp->time_ns_for_children); goto out_time; } new_nsp->time_ns = get_time_ns(tsk->nsproxy->time_ns); return new_nsp; out_time: put_net(new_nsp->net_ns);out_net: put_cgroup_ns(new_nsp->cgroup_ns);out_cgroup: put_pid_ns(new_nsp->pid_ns_for_children);out_pid: put_ipc_ns(new_nsp->ipc_ns);out_ipc: put_uts_ns(new_nsp->uts_ns);out_uts: put_mnt_ns(new_nsp->mnt_ns);out_ns: kmem_cache_free(nsproxy_cachep, new_nsp); return ERR_PTR(err);} /* * called from clone. This now handles copy for nsproxy and all * namespaces therein. */int copy_namespaces(unsigned long flags, struct task_struct *tsk){ struct nsproxy *old_ns = tsk->nsproxy; struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns); struct nsproxy *new_ns; if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWPID | CLONE_NEWNET | CLONE_NEWCGROUP | CLONE_NEWTIME)))) { if ((flags & CLONE_VM) || likely(old_ns->time_ns_for_children == old_ns->time_ns)) { get_nsproxy(old_ns); return 0; } } else if (!ns_capable(user_ns, CAP_SYS_ADMIN)) return -EPERM; /* * CLONE_NEWIPC must detach from the undolist: after switching * to a new ipc namespace, the semaphore arrays from the old * namespace are unreachable. In clone parlance, CLONE_SYSVSEM * means share undolist with parent, so we must forbid using * it along with CLONE_NEWIPC. */ if ((flags & (CLONE_NEWIPC | CLONE_SYSVSEM)) == (CLONE_NEWIPC | CLONE_SYSVSEM)) return -EINVAL; new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs); if (IS_ERR(new_ns)) return PTR_ERR(new_ns); if ((flags & CLONE_VM) == 0) timens_on_fork(new_ns, tsk); tsk->nsproxy = new_ns; return 0;} void free_nsproxy(struct nsproxy *ns){ put_mnt_ns(ns->mnt_ns); put_uts_ns(ns->uts_ns); put_ipc_ns(ns->ipc_ns); put_pid_ns(ns->pid_ns_for_children); put_time_ns(ns->time_ns); put_time_ns(ns->time_ns_for_children); put_cgroup_ns(ns->cgroup_ns); put_net(ns->net_ns); kmem_cache_free(nsproxy_cachep, ns);} /* * Called from unshare. Unshare all the namespaces part of nsproxy. * On success, returns the new nsproxy. */int unshare_nsproxy_namespaces(unsigned long unshare_flags, struct nsproxy **new_nsp, struct cred *new_cred, struct fs_struct *new_fs){ struct user_namespace *user_ns; int err = 0; if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP | CLONE_NEWTIME))) return 0; user_ns = new_cred ? new_cred->user_ns : current_user_ns(); if (!ns_capable(user_ns, CAP_SYS_ADMIN)) return -EPERM; *new_nsp = create_new_namespaces(unshare_flags, current, user_ns, new_fs ? new_fs : current->fs); if (IS_ERR(*new_nsp)) { err = PTR_ERR(*new_nsp); goto out; } out: return err;} void switch_task_namespaces(struct task_struct *p, struct nsproxy *new){ struct nsproxy *ns; might_sleep(); task_lock(p); ns = p->nsproxy; p->nsproxy = new; task_unlock(p); if (ns) put_nsproxy(ns);} void exit_task_namespaces(struct task_struct *p){ switch_task_namespaces(p, NULL);} int exec_task_namespaces(void){ struct task_struct *tsk = current; struct nsproxy *new; if (tsk->nsproxy->time_ns_for_children == tsk->nsproxy->time_ns) return 0; new = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs); if (IS_ERR(new)) return PTR_ERR(new); timens_on_fork(new, tsk); switch_task_namespaces(tsk, new); return 0;} static int check_setns_flags(unsigned long flags){ if (!flags || (flags & ~(CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWNET | CLONE_NEWTIME | CLONE_NEWUSER | CLONE_NEWPID | CLONE_NEWCGROUP))) return -EINVAL; #ifndef CONFIG_USER_NS if (flags & CLONE_NEWUSER) return -EINVAL;#endif#ifndef CONFIG_PID_NS if (flags & CLONE_NEWPID) return -EINVAL;#endif#ifndef CONFIG_UTS_NS if (flags & CLONE_NEWUTS) return -EINVAL;#endif#ifndef CONFIG_IPC_NS if (flags & CLONE_NEWIPC) return -EINVAL;#endif#ifndef CONFIG_CGROUPS if (flags & CLONE_NEWCGROUP) return -EINVAL;#endif#ifndef CONFIG_NET_NS if (flags & CLONE_NEWNET) return -EINVAL;#endif#ifndef CONFIG_TIME_NS if (flags & CLONE_NEWTIME) return -EINVAL;#endif return 0;} static void put_nsset(struct nsset *nsset){ unsigned flags = nsset->flags; if (flags & CLONE_NEWUSER) put_cred(nsset_cred(nsset)); /* * We only created a temporary copy if we attached to more than just * the mount namespace. */ if (nsset->fs && (flags & CLONE_NEWNS) && (flags & ~CLONE_NEWNS)) free_fs_struct(nsset->fs); if (nsset->nsproxy) free_nsproxy(nsset->nsproxy);} static int prepare_nsset(unsigned flags, struct nsset *nsset){ struct task_struct *me = current; nsset->nsproxy = create_new_namespaces(0, me, current_user_ns(), me->fs); if (IS_ERR(nsset->nsproxy)) return PTR_ERR(nsset->nsproxy); if (flags & CLONE_NEWUSER) nsset->cred = prepare_creds(); else nsset->cred = current_cred(); if (!nsset->cred) goto out; /* Only create a temporary copy of fs_struct if we really need to. */ if (flags == CLONE_NEWNS) { nsset->fs = me->fs; } else if (flags & CLONE_NEWNS) { nsset->fs = copy_fs_struct(me->fs); if (!nsset->fs) goto out; } nsset->flags = flags; return 0; out: put_nsset(nsset); return -ENOMEM;} static inline int validate_ns(struct nsset *nsset, struct ns_common *ns){ return ns->ops->install(nsset, ns);} /* * This is the inverse operation to unshare(). * Ordering is equivalent to the standard ordering used everywhere else * during unshare and process creation. The switch to the new set of * namespaces occurs at the point of no return after installation of * all requested namespaces was successful in commit_nsset(). */static int validate_nsset(struct nsset *nsset, struct pid *pid){ int ret = 0; unsigned flags = nsset->flags; struct user_namespace *user_ns = NULL; struct pid_namespace *pid_ns = NULL; struct nsproxy *nsp; struct task_struct *tsk; /* Take a "snapshot" of the target task's namespaces. */ rcu_read_lock(); tsk = pid_task(pid, PIDTYPE_PID); if (!tsk) { rcu_read_unlock(); return -ESRCH; } if (!ptrace_may_access(tsk, PTRACE_MODE_READ_REALCREDS)) { rcu_read_unlock(); return -EPERM; } task_lock(tsk); nsp = tsk->nsproxy; if (nsp) get_nsproxy(nsp); task_unlock(tsk); if (!nsp) { rcu_read_unlock(); return -ESRCH; } #ifdef CONFIG_PID_NS if (flags & CLONE_NEWPID) { pid_ns = task_active_pid_ns(tsk); if (unlikely(!pid_ns)) { rcu_read_unlock(); ret = -ESRCH; goto out; } get_pid_ns(pid_ns); }#endif #ifdef CONFIG_USER_NS if (flags & CLONE_NEWUSER) user_ns = get_user_ns(__task_cred(tsk)->user_ns);#endif rcu_read_unlock(); /* * Install requested namespaces. The caller will have * verified earlier that the requested namespaces are * supported on this kernel. We don't report errors here * if a namespace is requested that isn't supported. */#ifdef CONFIG_USER_NS if (flags & CLONE_NEWUSER) { ret = validate_ns(nsset, &user_ns->ns); if (ret) goto out; }#endif if (flags & CLONE_NEWNS) { ret = validate_ns(nsset, from_mnt_ns(nsp->mnt_ns)); if (ret) goto out; } #ifdef CONFIG_UTS_NS if (flags & CLONE_NEWUTS) { ret = validate_ns(nsset, &nsp->uts_ns->ns); if (ret) goto out; }#endif #ifdef CONFIG_IPC_NS if (flags & CLONE_NEWIPC) { ret = validate_ns(nsset, &nsp->ipc_ns->ns); if (ret) goto out; }#endif #ifdef CONFIG_PID_NS if (flags & CLONE_NEWPID) { ret = validate_ns(nsset, &pid_ns->ns); if (ret) goto out; }#endif #ifdef CONFIG_CGROUPS if (flags & CLONE_NEWCGROUP) { ret = validate_ns(nsset, &nsp->cgroup_ns->ns); if (ret) goto out; }#endif #ifdef CONFIG_NET_NS if (flags & CLONE_NEWNET) { ret = validate_ns(nsset, &nsp->net_ns->ns); if (ret) goto out; }#endif #ifdef CONFIG_TIME_NS if (flags & CLONE_NEWTIME) { ret = validate_ns(nsset, &nsp->time_ns->ns); if (ret) goto out; }#endif out: if (pid_ns) put_pid_ns(pid_ns); if (nsp) put_nsproxy(nsp); put_user_ns(user_ns); return ret;} /* * This is the point of no return. There are just a few namespaces * that do some actual work here and it's sufficiently minimal that * a separate ns_common operation seems unnecessary for now. * Unshare is doing the same thing. If we'll end up needing to do * more in a given namespace or a helper here is ultimately not * exported anymore a simple commit handler for each namespace * should be added to ns_common.Lines 1–500 of 580. Load more
// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2006 IBM Corporation * * Author: Serge Hallyn <serue@us.ibm.com> * * Jun 2006 - namespaces support * OpenVZ, SWsoft Inc. * Pavel Emelianov <xemul@openvz.org> */ #include <linux/slab.h> #include <linux/export.h> #include <linux/nsproxy.h> #include <linux/init_task.h> #include <linux/mnt_namespace.h> #include <linux/utsname.h> #include <linux/pid_namespace.h> #include <net/net_namespace.h> #include <linux/ipc_namespace.h> #include <linux/time_namespace.h> #include <linux/fs_struct.h> #include <linux/proc_fs.h> #include <linux/proc_ns.h> #include <linux/file.h> #include <linux/syscalls.h> #include <linux/cgroup.h> #include <linux/perf_event.h> static struct kmem_cache *nsproxy_cachep; struct nsproxy init_nsproxy = { .count = REFCOUNT_INIT(1), .uts_ns = &init_uts_ns, #if defined(CONFIG_POSIX_MQUEUE) || defined(CONFIG_SYSVIPC) .ipc_ns = &init_ipc_ns, #endif .mnt_ns = NULL, .pid_ns_for_children = &init_pid_ns, #ifdef CONFIG_NET .net_ns = &init_net, #endif #ifdef CONFIG_CGROUPS .cgroup_ns = &init_cgroup_ns, #endif #ifdef CONFIG_TIME_NS .time_ns = &init_time_ns, .time_ns_for_children = &init_time_ns, #endif }; static inline struct nsproxy *create_nsproxy(void) { struct nsproxy *nsproxy; nsproxy = kmem_cache_alloc(nsproxy_cachep, GFP_KERNEL); if (nsproxy) refcount_set(&nsproxy->count, 1); return nsproxy; } /* * Create new nsproxy and all of its the associated namespaces. * Return the newly created nsproxy. Do not attach this to the task, * leave it to the caller to do proper locking and attach it to task. */ static struct nsproxy *create_new_namespaces(unsigned long flags, struct task_struct *tsk, struct user_namespace *user_ns, struct fs_struct *new_fs) { struct nsproxy *new_nsp; int err; new_nsp = create_nsproxy(); if (!new_nsp) return ERR_PTR(-ENOMEM); new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, user_ns, new_fs); if (IS_ERR(new_nsp->mnt_ns)) { err = PTR_ERR(new_nsp->mnt_ns); goto out_ns; } new_nsp->uts_ns = copy_utsname(flags, user_ns, tsk->nsproxy->uts_ns); if (IS_ERR(new_nsp->uts_ns)) { err = PTR_ERR(new_nsp->uts_ns); goto out_uts; } new_nsp->ipc_ns = copy_ipcs(flags, user_ns, tsk->nsproxy->ipc_ns); if (IS_ERR(new_nsp->ipc_ns)) { err = PTR_ERR(new_nsp->ipc_ns); goto out_ipc; } 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; } new_nsp->cgroup_ns = copy_cgroup_ns(flags, user_ns, tsk->nsproxy->cgroup_ns); if (IS_ERR(new_nsp->cgroup_ns)) { err = PTR_ERR(new_nsp->cgroup_ns); goto out_cgroup; } new_nsp->net_ns = copy_net_ns(flags, user_ns, tsk->nsproxy->net_ns); if (IS_ERR(new_nsp->net_ns)) { err = PTR_ERR(new_nsp->net_ns); goto out_net; } new_nsp->time_ns_for_children = copy_time_ns(flags, user_ns, tsk->nsproxy->time_ns_for_children); if (IS_ERR(new_nsp->time_ns_for_children)) { err = PTR_ERR(new_nsp->time_ns_for_children); goto out_time; } new_nsp->time_ns = get_time_ns(tsk->nsproxy->time_ns); return new_nsp; out_time: put_net(new_nsp->net_ns); out_net: put_cgroup_ns(new_nsp->cgroup_ns); out_cgroup: put_pid_ns(new_nsp->pid_ns_for_children); out_pid: put_ipc_ns(new_nsp->ipc_ns); out_ipc: put_uts_ns(new_nsp->uts_ns); out_uts: put_mnt_ns(new_nsp->mnt_ns); out_ns: kmem_cache_free(nsproxy_cachep, new_nsp); return ERR_PTR(err); } /* * called from clone. This now handles copy for nsproxy and all * namespaces therein. */ int copy_namespaces(unsigned long flags, struct task_struct *tsk) { struct nsproxy *old_ns = tsk->nsproxy; struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns); struct nsproxy *new_ns; if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWPID | CLONE_NEWNET | CLONE_NEWCGROUP | CLONE_NEWTIME)))) { if ((flags & CLONE_VM) || likely(old_ns->time_ns_for_children == old_ns->time_ns)) { get_nsproxy(old_ns); return 0; } } else if (!ns_capable(user_ns, CAP_SYS_ADMIN)) return -EPERM; /* * CLONE_NEWIPC must detach from the undolist: after switching * to a new ipc namespace, the semaphore arrays from the old * namespace are unreachable. In clone parlance, CLONE_SYSVSEM * means share undolist with parent, so we must forbid using * it along with CLONE_NEWIPC. */ if ((flags & (CLONE_NEWIPC | CLONE_SYSVSEM)) == (CLONE_NEWIPC | CLONE_SYSVSEM)) return -EINVAL; new_ns = create_new_namespaces(flags, tsk, user_ns, tsk->fs); if (IS_ERR(new_ns)) return PTR_ERR(new_ns); if ((flags & CLONE_VM) == 0) timens_on_fork(new_ns, tsk); tsk->nsproxy = new_ns; return 0; } void free_nsproxy(struct nsproxy *ns) { put_mnt_ns(ns->mnt_ns); put_uts_ns(ns->uts_ns); put_ipc_ns(ns->ipc_ns); put_pid_ns(ns->pid_ns_for_children); put_time_ns(ns->time_ns); put_time_ns(ns->time_ns_for_children); put_cgroup_ns(ns->cgroup_ns); put_net(ns->net_ns); kmem_cache_free(nsproxy_cachep, ns); } /* * Called from unshare. Unshare all the namespaces part of nsproxy. * On success, returns the new nsproxy. */ int unshare_nsproxy_namespaces(unsigned long unshare_flags, struct nsproxy **new_nsp, struct cred *new_cred, struct fs_struct *new_fs) { struct user_namespace *user_ns; int err = 0; if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWNET | CLONE_NEWPID | CLONE_NEWCGROUP | CLONE_NEWTIME))) return 0; user_ns = new_cred ? new_cred->user_ns : current_user_ns(); if (!ns_capable(user_ns, CAP_SYS_ADMIN)) return -EPERM; *new_nsp = create_new_namespaces(unshare_flags, current, user_ns, new_fs ? new_fs : current->fs); if (IS_ERR(*new_nsp)) { err = PTR_ERR(*new_nsp); goto out; } out: return err; } void switch_task_namespaces(struct task_struct *p, struct nsproxy *new) { struct nsproxy *ns; might_sleep(); task_lock(p); ns = p->nsproxy; p->nsproxy = new; task_unlock(p); if (ns) put_nsproxy(ns); } void exit_task_namespaces(struct task_struct *p) { switch_task_namespaces(p, NULL); } int exec_task_namespaces(void) { struct task_struct *tsk = current; struct nsproxy *new; if (tsk->nsproxy->time_ns_for_children == tsk->nsproxy->time_ns) return 0; new = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs); if (IS_ERR(new)) return PTR_ERR(new); timens_on_fork(new, tsk); switch_task_namespaces(tsk, new); return 0; } static int check_setns_flags(unsigned long flags) { if (!flags || (flags & ~(CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | CLONE_NEWNET | CLONE_NEWTIME | CLONE_NEWUSER | CLONE_NEWPID | CLONE_NEWCGROUP))) return -EINVAL; #ifndef CONFIG_USER_NS if (flags & CLONE_NEWUSER) return -EINVAL; #endif #ifndef CONFIG_PID_NS if (flags & CLONE_NEWPID) return -EINVAL; #endif #ifndef CONFIG_UTS_NS if (flags & CLONE_NEWUTS) return -EINVAL; #endif #ifndef CONFIG_IPC_NS if (flags & CLONE_NEWIPC) return -EINVAL; #endif #ifndef CONFIG_CGROUPS if (flags & CLONE_NEWCGROUP) return -EINVAL; #endif #ifndef CONFIG_NET_NS if (flags & CLONE_NEWNET) return -EINVAL; #endif #ifndef CONFIG_TIME_NS if (flags & CLONE_NEWTIME) return -EINVAL; #endif return 0; } static void put_nsset(struct nsset *nsset) { unsigned flags = nsset->flags; if (flags & CLONE_NEWUSER) put_cred(nsset_cred(nsset)); /* * We only created a temporary copy if we attached to more than just * the mount namespace. */ if (nsset->fs && (flags & CLONE_NEWNS) && (flags & ~CLONE_NEWNS)) free_fs_struct(nsset->fs); if (nsset->nsproxy) free_nsproxy(nsset->nsproxy); } static int prepare_nsset(unsigned flags, struct nsset *nsset) { struct task_struct *me = current; nsset->nsproxy = create_new_namespaces(0, me, current_user_ns(), me->fs); if (IS_ERR(nsset->nsproxy)) return PTR_ERR(nsset->nsproxy); if (flags & CLONE_NEWUSER) nsset->cred = prepare_creds(); else nsset->cred = current_cred(); if (!nsset->cred) goto out; /* Only create a temporary copy of fs_struct if we really need to. */ if (flags == CLONE_NEWNS) { nsset->fs = me->fs; } else if (flags & CLONE_NEWNS) { nsset->fs = copy_fs_struct(me->fs); if (!nsset->fs) goto out; } nsset->flags = flags; return 0; out: put_nsset(nsset); return -ENOMEM; } static inline int validate_ns(struct nsset *nsset, struct ns_common *ns) { return ns->ops->install(nsset, ns); } /* * This is the inverse operation to unshare(). * Ordering is equivalent to the standard ordering used everywhere else * during unshare and process creation. The switch to the new set of * namespaces occurs at the point of no return after installation of * all requested namespaces was successful in commit_nsset(). */ static int validate_nsset(struct nsset *nsset, struct pid *pid) { int ret = 0; unsigned flags = nsset->flags; struct user_namespace *user_ns = NULL; struct pid_namespace *pid_ns = NULL; struct nsproxy *nsp; struct task_struct *tsk; /* Take a "snapshot" of the target task's namespaces. */ rcu_read_lock(); tsk = pid_task(pid, PIDTYPE_PID); if (!tsk) { rcu_read_unlock(); return -ESRCH; } if (!ptrace_may_access(tsk, PTRACE_MODE_READ_REALCREDS)) { rcu_read_unlock(); return -EPERM; } task_lock(tsk); nsp = tsk->nsproxy; if (nsp) get_nsproxy(nsp); task_unlock(tsk); if (!nsp) { rcu_read_unlock(); return -ESRCH; } #ifdef CONFIG_PID_NS if (flags & CLONE_NEWPID) { pid_ns = task_active_pid_ns(tsk); if (unlikely(!pid_ns)) { rcu_read_unlock(); ret = -ESRCH; goto out; } get_pid_ns(pid_ns); } #endif #ifdef CONFIG_USER_NS if (flags & CLONE_NEWUSER) user_ns = get_user_ns(__task_cred(tsk)->user_ns); #endif rcu_read_unlock(); /* * Install requested namespaces. The caller will have * verified earlier that the requested namespaces are * supported on this kernel. We don't report errors here * if a namespace is requested that isn't supported. */ #ifdef CONFIG_USER_NS if (flags & CLONE_NEWUSER) { ret = validate_ns(nsset, &user_ns->ns); if (ret) goto out; } #endif if (flags & CLONE_NEWNS) { ret = validate_ns(nsset, from_mnt_ns(nsp->mnt_ns)); if (ret) goto out; } #ifdef CONFIG_UTS_NS if (flags & CLONE_NEWUTS) { ret = validate_ns(nsset, &nsp->uts_ns->ns); if (ret) goto out; } #endif #ifdef CONFIG_IPC_NS if (flags & CLONE_NEWIPC) { ret = validate_ns(nsset, &nsp->ipc_ns->ns); if (ret) goto out; } #endif #ifdef CONFIG_PID_NS if (flags & CLONE_NEWPID) { ret = validate_ns(nsset, &pid_ns->ns); if (ret) goto out; } #endif #ifdef CONFIG_CGROUPS if (flags & CLONE_NEWCGROUP) { ret = validate_ns(nsset, &nsp->cgroup_ns->ns); if (ret) goto out; } #endif #ifdef CONFIG_NET_NS if (flags & CLONE_NEWNET) { ret = validate_ns(nsset, &nsp->net_ns->ns); if (ret) goto out; } #endif #ifdef CONFIG_TIME_NS if (flags & CLONE_NEWTIME) { ret = validate_ns(nsset, &nsp->time_ns->ns); if (ret) goto out; } #endif out: if (pid_ns) put_pid_ns(pid_ns); if (nsp) put_nsproxy(nsp); put_user_ns(user_ns); return ret; } /* * This is the point of no return. There are just a few namespaces * that do some actual work here and it's sufficiently minimal that * a separate ns_common operation seems unnecessary for now. * Unshare is doing the same thing. If we'll end up needing to do * more in a given namespace or a helper here is ultimately not * exported anymore a simple commit handler for each namespace * should be added to ns_common.