diff options
| -rw-r--r-- | fs/namespace.c | 30 | ||||
| -rw-r--r-- | include/linux/ipc.h | 11 | ||||
| -rw-r--r-- | include/linux/mnt_namespace.h | 5 | ||||
| -rw-r--r-- | include/linux/nsproxy.h | 3 | ||||
| -rw-r--r-- | include/linux/pid_namespace.h | 2 | ||||
| -rw-r--r-- | include/linux/utsname.h | 19 | ||||
| -rw-r--r-- | ipc/util.c | 53 | ||||
| -rw-r--r-- | kernel/fork.c | 85 | ||||
| -rw-r--r-- | kernel/nsproxy.c | 139 | ||||
| -rw-r--r-- | kernel/pid.c | 11 | ||||
| -rw-r--r-- | kernel/utsname.c | 41 |
11 files changed, 131 insertions, 268 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index fd999ca..be5e56b 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1441,10 +1441,9 @@ dput_out: * Allocate a new namespace structure and populate it with contents * copied from the namespace of the passed in task structure. */ -struct mnt_namespace *dup_mnt_ns(struct task_struct *tsk, +static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, struct fs_struct *fs) { - struct mnt_namespace *mnt_ns = tsk->nsproxy->mnt_ns; struct mnt_namespace *new_ns; struct vfsmount *rootmnt = NULL, *pwdmnt = NULL, *altrootmnt = NULL; struct vfsmount *p, *q; @@ -1509,36 +1508,21 @@ struct mnt_namespace *dup_mnt_ns(struct task_struct *tsk, return new_ns; } -int copy_mnt_ns(int flags, struct task_struct *tsk) +struct mnt_namespace *copy_mnt_ns(int flags, struct mnt_namespace *ns, + struct fs_struct *new_fs) { - struct mnt_namespace *ns = tsk->nsproxy->mnt_ns; struct mnt_namespace *new_ns; - int err = 0; - - if (!ns) - return 0; + BUG_ON(!ns); get_mnt_ns(ns); if (!(flags & CLONE_NEWNS)) - return 0; - - if (!capable(CAP_SYS_ADMIN)) { - err = -EPERM; - goto out; - } - - new_ns = dup_mnt_ns(tsk, tsk->fs); - if (!new_ns) { - err = -ENOMEM; - goto out; - } + return ns; - tsk->nsproxy->mnt_ns = new_ns; + new_ns = dup_mnt_ns(ns, new_fs); -out: put_mnt_ns(ns); - return err; + return new_ns; } asmlinkage long sys_mount(char __user * dev_name, char __user * dir_name, diff --git a/include/linux/ipc.h b/include/linux/ipc.h index 6da6772..1980867 100644 --- a/include/linux/ipc.h +++ b/include/linux/ipc.h @@ -92,16 +92,19 @@ extern struct ipc_namespace init_ipc_ns; #ifdef CONFIG_SYSVIPC #define INIT_IPC_NS(ns) .ns = &init_ipc_ns, -extern int copy_ipcs(unsigned long flags, struct task_struct *tsk); +extern struct ipc_namespace *copy_ipcs(unsigned long flags, + struct ipc_namespace *ns); #else #define INIT_IPC_NS(ns) -static inline int copy_ipcs(unsigned long flags, struct task_struct *tsk) -{ return 0; } +static inline struct ipc_namespace *copy_ipcs(unsigned long flags, + struct ipc_namespace *ns) +{ + return ns; +} #endif #ifdef CONFIG_IPC_NS extern void free_ipc_ns(struct kref *kref); -extern int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns); #endif static inline struct ipc_namespace *get_ipc_ns(struct ipc_namespace *ns) diff --git a/include/linux/mnt_namespace.h b/include/linux/mnt_namespace.h index 4af0b1f..1fa4d98 100644 --- a/include/linux/mnt_namespace.h +++ b/include/linux/mnt_namespace.h @@ -14,10 +14,9 @@ struct mnt_namespace { int event; }; -extern int copy_mnt_ns(int, struct task_struct *); -extern void __put_mnt_ns(struct mnt_namespace *ns); -extern struct mnt_namespace *dup_mnt_ns(struct task_struct *, +extern struct mnt_namespace *copy_mnt_ns(int, struct mnt_namespace *, struct fs_struct *); +extern void __put_mnt_ns(struct mnt_namespace *ns); static inline void put_mnt_ns(struct mnt_namespace *ns) { diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h index 0b9f0dc..189e0dc 100644 --- a/include/linux/nsproxy.h +++ b/include/linux/nsproxy.h @@ -31,10 +31,11 @@ struct nsproxy { }; extern struct nsproxy init_nsproxy; -struct nsproxy *dup_namespaces(struct nsproxy *orig); int copy_namespaces(int flags, struct task_struct *tsk); void get_task_namespaces(struct task_struct *tsk); void free_nsproxy(struct nsproxy *ns); +int unshare_nsproxy_namespaces(unsigned long, struct nsproxy **, + struct fs_struct *); static inline void put_nsproxy(struct nsproxy *ns) { diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h index 2833806..169c6c2 100644 --- a/include/linux/pid_namespace.h +++ b/include/linux/pid_namespace.h @@ -29,7 +29,7 @@ static inline void get_pid_ns(struct pid_namespace *ns) kref_get(&ns->kref); } -extern int copy_pid_ns(int flags, struct task_struct *tsk); +extern struct pid_namespace *copy_pid_ns(int flags, struct pid_namespace *ns); extern void free_pid_ns(struct kref *kref); static inline void put_pid_ns(struct pid_namespace *ns) diff --git a/include/linux/utsname.h b/include/linux/utsname.h index e10267d..f8d3b32 100644 --- a/include/linux/utsname.h +++ b/include/linux/utsname.h @@ -49,9 +49,7 @@ static inline void get_uts_ns(struct uts_namespace *ns) } #ifdef CONFIG_UTS_NS -extern int unshare_utsname(unsigned long unshare_flags, - struct uts_namespace **new_uts); -extern int copy_utsname(int flags, struct task_struct *tsk); +extern struct uts_namespace *copy_utsname(int flags, struct uts_namespace *ns); extern void free_uts_ns(struct kref *kref); static inline void put_uts_ns(struct uts_namespace *ns) @@ -59,21 +57,12 @@ static inline void put_uts_ns(struct uts_namespace *ns) kref_put(&ns->kref, free_uts_ns); } #else -static inline int unshare_utsname(unsigned long unshare_flags, - struct uts_namespace **new_uts) +static inline struct uts_namespace *copy_utsname(int flags, + struct uts_namespace *ns) { - if (unshare_flags & CLONE_NEWUTS) - return -EINVAL; - - return 0; + return ns; } -static inline int copy_utsname(int flags, struct task_struct *tsk) -{ - if (flags & CLONE_NEWUTS) - return -EINVAL; - return 0; -} static inline void put_uts_ns(struct uts_namespace *ns) { } @@ -85,53 +85,20 @@ err_mem: return ERR_PTR(err); } -int unshare_ipcs(unsigned long unshare_flags, struct ipc_namespace **new_ipc) +struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns) { - struct ipc_namespace *new; - - if (unshare_flags & CLONE_NEWIPC) { - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - new = clone_ipc_ns(current->nsproxy->ipc_ns); - if (IS_ERR(new)) - return PTR_ERR(new); - - *new_ipc = new; - } - - return 0; -} - -int copy_ipcs(unsigned long flags, struct task_struct *tsk) -{ - struct ipc_namespace *old_ns = tsk->nsproxy->ipc_ns; struct ipc_namespace *new_ns; - int err = 0; - if (!old_ns) - return 0; - - get_ipc_ns(old_ns); + BUG_ON(!ns); + get_ipc_ns(ns); if (!(flags & CLONE_NEWIPC)) - return 0; + return ns; - if (!capable(CAP_SYS_ADMIN)) { - err = -EPERM; - goto out; - } + new_ns = clone_ipc_ns(ns); - new_ns = clone_ipc_ns(old_ns); - if (!new_ns) { - err = -ENOMEM; - goto out; - } - - tsk->nsproxy->ipc_ns = new_ns; -out: - put_ipc_ns(old_ns); - return err; + put_ipc_ns(ns); + return new_ns; } void free_ipc_ns(struct kref *kref) @@ -145,11 +112,11 @@ void free_ipc_ns(struct kref *kref) kfree(ns); } #else -int copy_ipcs(unsigned long flags, struct task_struct *tsk) +struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns) { if (flags & CLONE_NEWIPC) - return -EINVAL; - return 0; + return ERR_PTR(-EINVAL); + return ns; } #endif diff --git a/kernel/fork.c b/kernel/fork.c index b7d169d..fd211b9 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1516,26 +1516,6 @@ static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp) } /* - * Unshare the mnt_namespace structure if it is being shared - */ -static int unshare_mnt_namespace(unsigned long unshare_flags, - struct mnt_namespace **new_nsp, struct fs_struct *new_fs) -{ - struct mnt_namespace *ns = current->nsproxy->mnt_ns; - - if ((unshare_flags & CLONE_NEWNS) && ns) { - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - *new_nsp = dup_mnt_ns(current, new_fs ? new_fs : current->fs); - if (!*new_nsp) - return -ENOMEM; - } - - return 0; -} - -/* * Unsharing of sighand is not supported yet */ static int unshare_sighand(unsigned long unshare_flags, struct sighand_struct **new_sighp) @@ -1593,16 +1573,6 @@ static int unshare_semundo(unsigned long unshare_flags, struct sem_undo_list **n return 0; } -#ifndef CONFIG_IPC_NS -static inline int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns) -{ - if (flags & CLONE_NEWIPC) - return -EINVAL; - - return 0; -} -#endif - /* * unshare allows a process to 'unshare' part of the process * context which was originally shared using clone. copy_* @@ -1615,14 +1585,11 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) { int err = 0; struct fs_struct *fs, *new_fs = NULL; - struct mnt_namespace *ns, *new_ns = NULL; struct sighand_struct *new_sigh = NULL; struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL; struct files_struct *fd, *new_fd = NULL; struct sem_undo_list *new_ulist = NULL; struct nsproxy *new_nsproxy = NULL, *old_nsproxy = NULL; - struct uts_namespace *uts, *new_uts = NULL; - struct ipc_namespace *ipc, *new_ipc = NULL; check_unshare_flags(&unshare_flags); @@ -1637,36 +1604,24 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) goto bad_unshare_out; if ((err = unshare_fs(unshare_flags, &new_fs))) goto bad_unshare_cleanup_thread; - if ((err = unshare_mnt_namespace(unshare_flags, &new_ns, new_fs))) - goto bad_unshare_cleanup_fs; if ((err = unshare_sighand(unshare_flags, &new_sigh))) - goto bad_unshare_cleanup_ns; + goto bad_unshare_cleanup_fs; if ((err = unshare_vm(unshare_flags, &new_mm))) goto bad_unshare_cleanup_sigh; if ((err = unshare_fd(unshare_flags, &new_fd))) goto bad_unshare_cleanup_vm; if ((err = unshare_semundo(unshare_flags, &new_ulist))) goto bad_unshare_cleanup_fd; - if ((err = unshare_utsname(unshare_flags, &new_uts))) + if ((err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy, + new_fs))) goto bad_unshare_cleanup_semundo; - if ((err = unshare_ipcs(unshare_flags, &new_ipc))) - goto bad_unshare_cleanup_uts; - - if (new_ns || new_uts || new_ipc) { - old_nsproxy = current->nsproxy; - new_nsproxy = dup_namespaces(old_nsproxy); - if (!new_nsproxy) { - err = -ENOMEM; - goto bad_unshare_cleanup_ipc; - } - } - if (new_fs || new_ns || new_mm || new_fd || new_ulist || - new_uts || new_ipc) { + if (new_fs || new_mm || new_fd || new_ulist || new_nsproxy) { task_lock(current); if (new_nsproxy) { + old_nsproxy = current->nsproxy; current->nsproxy = new_nsproxy; new_nsproxy = old_nsproxy; } @@ -1677,12 +1632,6 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) new_fs = fs; } - if (new_ns) { - ns = current->nsproxy->mnt_ns; - current->nsproxy->mnt_ns = new_ns; - new_ns = ns; - } - if (new_mm) { mm = current->mm; active_mm = current->active_mm; @@ -1698,32 +1647,12 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) new_fd = fd; } - if (new_uts) { - uts = current->nsproxy->uts_ns; - current->nsproxy->uts_ns = new_uts; - new_uts = uts; - } - - if (new_ipc) { - ipc = current->nsproxy->ipc_ns; - current->nsproxy->ipc_ns = new_ipc; - new_ipc = ipc; - } - task_unlock(current); } if (new_nsproxy) put_nsproxy(new_nsproxy); -bad_unshare_cleanup_ipc: - if (new_ipc) - put_ipc_ns(new_ipc); - -bad_unshare_cleanup_uts: - if (new_uts) - put_uts_ns(new_uts); - bad_unshare_cleanup_semundo: bad_unshare_cleanup_fd: if (new_fd) @@ -1738,10 +1667,6 @@ bad_unshare_cleanup_sigh: if (atomic_dec_and_test(&new_sigh->count)) kmem_cache_free(sighand_cachep, new_sigh); -bad_unshare_cleanup_ns: - if (new_ns) - put_mnt_ns(new_ns); - bad_unshare_cleanup_fs: if (new_fs) put_fs_struct(new_fs); diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index f5b9ee6..1bc4b55 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -38,10 +38,8 @@ void get_task_namespaces(struct task_struct *tsk) /* * creates a copy of "orig" with refcount 1. - * This does not grab references to the contained namespaces, - * so that needs to be done by dup_namespaces. */ -static inline struct nsproxy *clone_namespaces(struct nsproxy *orig) +static inline struct nsproxy *clone_nsproxy(struct nsproxy *orig) { struct nsproxy *ns; @@ -52,26 +50,49 @@ static inline struct nsproxy *clone_namespaces(struct nsproxy *orig) } /* - * copies the nsproxy, setting refcount to 1, and grabbing a - * reference to all contained namespaces. Called from - * sys_unshare() + * 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. */ -struct nsproxy *dup_namespaces(struct nsproxy *orig) +static struct nsproxy *create_new_namespaces(int flags, struct task_struct *tsk, + struct fs_struct *new_fs) { - struct nsproxy *ns = clone_namespaces(orig); + struct nsproxy *new_nsp; - if (ns) { - if (ns->mnt_ns) - get_mnt_ns(ns->mnt_ns); - if (ns->uts_ns) - get_uts_ns(ns->uts_ns); - if (ns->ipc_ns) - get_ipc_ns(ns->ipc_ns); - if (ns->pid_ns) - get_pid_ns(ns->pid_ns); - } + new_nsp = clone_nsproxy(tsk->nsproxy); + if (!new_nsp) + return ERR_PTR(-ENOMEM); - return ns; + new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, new_fs); + if (IS_ERR(new_nsp->mnt_ns)) + goto out_ns; + + new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns); + if (IS_ERR(new_nsp->uts_ns)) + goto out_uts; + + new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns); + if (IS_ERR(new_nsp->ipc_ns)) + goto out_ipc; + + new_nsp->pid_ns = copy_pid_ns(flags, tsk->nsproxy->pid_ns); + if (IS_ERR(new_nsp->pid_ns)) + goto out_pid; + + return new_nsp; + +out_pid: + if (new_nsp->ipc_ns) + put_ipc_ns(new_nsp->ipc_ns); +out_ipc: + if (new_nsp->uts_ns) + put_uts_ns(new_nsp->uts_ns); +out_uts: + if (new_nsp->mnt_ns) + put_mnt_ns(new_nsp->mnt_ns); +out_ns: + kfree(new_nsp); + return ERR_PTR(-ENOMEM); } /* @@ -92,47 +113,21 @@ int copy_namespaces(int flags, struct task_struct *tsk) if (!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC))) return 0; - new_ns = clone_namespaces(old_ns); - if (!new_ns) { - err = -ENOMEM; + if (!capable(CAP_SYS_ADMIN)) { + err = -EPERM; goto out; } - tsk->nsproxy = new_ns; - - err = copy_mnt_ns(flags, tsk); - if (err) - goto out_ns; - - err = copy_utsname(flags, tsk); - if (err) - goto out_uts; - - err = copy_ipcs(flags, tsk); - if (err) - goto out_ipc; - - err = copy_pid_ns(flags, tsk); - if (err) - goto out_pid; + new_ns = create_new_namespaces(flags, tsk, tsk->fs); + if (IS_ERR(new_ns)) { + err = PTR_ERR(new_ns); + goto out; + } + tsk->nsproxy = new_ns; out: put_nsproxy(old_ns); return err; - -out_pid: - if (new_ns->ipc_ns) - put_ipc_ns(new_ns->ipc_ns); -out_ipc: - if (new_ns->uts_ns) - put_uts_ns(new_ns->uts_ns); -out_uts: - if (new_ns->mnt_ns) - put_mnt_ns(new_ns->mnt_ns); -out_ns: - tsk->nsproxy = old_ns; - kfree(new_ns); - goto out; } void free_nsproxy(struct nsproxy *ns) @@ -147,3 +142,41 @@ void free_nsproxy(struct nsproxy *ns) put_pid_ns(ns->pid_ns); kfree(ns); } + +/* + * Called from unshare. Unshare all the namespaces part of nsproxy. + * On sucess, returns the new nsproxy and a reference to old nsproxy + * to make sure it stays around. + */ +int unshare_nsproxy_namespaces(unsigned long unshare_flags, + struct nsproxy **new_nsp, struct fs_struct *new_fs) +{ + struct nsproxy *old_ns = current->nsproxy; + int err = 0; + + if (!(unshare_flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC))) + return 0; + +#ifndef CONFIG_IPC_NS + if (unshare_flags & CLONE_NEWIPC) + return -EINVAL; +#endif + +#ifndef CONFIG_UTS_NS + if (unshare_flags & CLONE_NEWUTS) + return -EINVAL; +#endif + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + get_nsproxy(old_ns); + + *new_nsp = create_new_namespaces(unshare_flags, current, + new_fs ? new_fs : current->fs); + if (IS_ERR(*new_nsp)) { + err = PTR_ERR(*new_nsp); + put_nsproxy(old_ns); + } + return err; +} diff --git a/kernel/pid.c b/kernel/pid.c index 9c80bc2..d3ad724 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -360,16 +360,11 @@ struct pid *find_ge_pid(int nr) } EXPORT_SYMBOL_GPL(find_get_pid); -int copy_pid_ns(int flags, struct task_struct *tsk) +struct pid_namespace *copy_pid_ns(int flags, struct pid_namespace *old_ns) { - struct pid_namespace *old_ns = tsk->nsproxy->pid_ns; - int err = 0; - - if (!old_ns) - return 0; - + BUG_ON(!old_ns); get_pid_ns(old_ns); - return err; + return old_ns; } void free_pid_ns(struct kref *kref) diff --git a/kernel/utsname.c b/kernel/utsname.c index c859164..160c8c5 100644 --- a/kernel/utsname.c +++ b/kernel/utsname.c @@ -32,58 +32,25 @@ static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns) } /* - * unshare the current process' utsname namespace. - * called only in sys_unshare() - */ -int unshare_utsname(unsigned long unshare_flags, struct uts_namespace **new_uts) -{ - if (unshare_flags & CLONE_NEWUTS) { - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - *new_uts = clone_uts_ns(current->nsproxy->uts_ns); - if (!*new_uts) - return -ENOMEM; - } - - return 0; -} - -/* * Copy task tsk's utsname namespace, or clone it if flags * specifies CLONE_NEWUTS. In latter case, changes to the * utsname of this process won't be seen by parent, and vice * versa. */ -int copy_utsname(int flags, struct task_struct *tsk) +struct uts_namespace *copy_utsname(int flags, struct uts_namespace *old_ns) { - struct uts_namespace *old_ns = tsk->nsproxy->uts_ns; struct uts_namespace *new_ns; - int err = 0; - - if (!old_ns) - return 0; + BUG_ON(!old_ns); get_uts_ns(old_ns); if (!(flags & CLONE_NEWUTS)) - return 0; - - if (!capable(CAP_SYS_ADMIN)) { - err = -EPERM; - goto out; - } + return old_ns; new_ns = clone_uts_ns(old_ns); - if (!new_ns) { - err = -ENOMEM; - goto out; - } - tsk->nsproxy->uts_ns = new_ns; -out: put_uts_ns(old_ns); - return err; + return new_ns; } void free_uts_ns(struct kref *kref) |
