From f2a8d52e0a4db968c346c4332630a71cba377567 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Tue, 5 May 2020 16:04:30 +0200 Subject: [PATCH 1/3] nsproxy: add struct nsset Add a simple struct nsset. It holds all necessary pieces to switch to a new set of namespaces without leaving a task in a half-switched state which we will make use of in the next patch. This patch switches the existing setns logic over without causing a change in setns() behavior. This brings setns() closer to how unshare() works(). The prepare_ns() function is responsible to prepare all necessary information. This has two reasons. First it minimizes dependencies between individual namespaces, i.e. all install handler can expect that all fields are properly initialized independent in what order they are called in. Second, this makes the code easier to maintain and easier to follow if it needs to be changed. The prepare_ns() helper will only be switched over to use a flags argument in the next patch. Here it will still use nstype as a simple integer argument which was argued would be clearer. I'm not particularly opinionated about this if it really helps or not. The struct nsset itself already contains the flags field since its name already indicates that it can contain information required by different namespaces. None of this should have functional consequences. Signed-off-by: Christian Brauner Reviewed-by: Serge Hallyn Cc: Eric W. Biederman Cc: Serge Hallyn Cc: Jann Horn Cc: Michael Kerrisk Cc: Aleksa Sarai Link: https://lore.kernel.org/r/20200505140432.181565-2-christian.brauner@ubuntu.com --- fs/namespace.c | 10 ++-- include/linux/mnt_namespace.h | 1 + include/linux/nsproxy.h | 24 ++++++++++ include/linux/proc_ns.h | 4 +- ipc/namespace.c | 7 ++- kernel/cgroup/namespace.c | 5 +- kernel/nsproxy.c | 90 ++++++++++++++++++++++++++++++----- kernel/pid_namespace.c | 5 +- kernel/time/namespace.c | 5 +- kernel/user_namespace.c | 8 ++-- kernel/utsname.c | 5 +- net/core/net_namespace.c | 5 +- 12 files changed, 132 insertions(+), 37 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index a28e4db075ede2..62899fad4a0404 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3954,16 +3954,18 @@ static void mntns_put(struct ns_common *ns) put_mnt_ns(to_mnt_ns(ns)); } -static int mntns_install(struct nsproxy *nsproxy, struct ns_common *ns) +static int mntns_install(struct nsset *nsset, struct ns_common *ns) { - struct fs_struct *fs = current->fs; + struct nsproxy *nsproxy = nsset->nsproxy; + struct fs_struct *fs = nsset->fs; struct mnt_namespace *mnt_ns = to_mnt_ns(ns), *old_mnt_ns; + struct user_namespace *user_ns = nsset->cred->user_ns; struct path root; int err; if (!ns_capable(mnt_ns->user_ns, CAP_SYS_ADMIN) || - !ns_capable(current_user_ns(), CAP_SYS_CHROOT) || - !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) + !ns_capable(user_ns, CAP_SYS_CHROOT) || + !ns_capable(user_ns, CAP_SYS_ADMIN)) return -EPERM; if (is_anon_ns(mnt_ns)) diff --git a/include/linux/mnt_namespace.h b/include/linux/mnt_namespace.h index 35942084cd40d5..007cfa52efb230 100644 --- a/include/linux/mnt_namespace.h +++ b/include/linux/mnt_namespace.h @@ -6,6 +6,7 @@ struct mnt_namespace; struct fs_struct; struct user_namespace; +struct ns_common; extern struct mnt_namespace *copy_mnt_ns(unsigned long, struct mnt_namespace *, struct user_namespace *, struct fs_struct *); diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h index 074f395b9ad254..cdb171efc7cb05 100644 --- a/include/linux/nsproxy.h +++ b/include/linux/nsproxy.h @@ -41,6 +41,30 @@ struct nsproxy { }; extern struct nsproxy init_nsproxy; +/* + * A structure to encompass all bits needed to install + * a partial or complete new set of namespaces. + * + * If a new user namespace is requested cred will + * point to a modifiable set of credentials. If a pointer + * to a modifiable set is needed nsset_cred() must be + * used and tested. + */ +struct nsset { + unsigned flags; + struct nsproxy *nsproxy; + struct fs_struct *fs; + const struct cred *cred; +}; + +static inline struct cred *nsset_cred(struct nsset *set) +{ + if (set->flags & CLONE_NEWUSER) + return (struct cred *)set->cred; + + return NULL; +} + /* * the namespaces access rules are: * diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index 6abe85c346813a..75807ecef880f1 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -8,7 +8,7 @@ #include struct pid_namespace; -struct nsproxy; +struct nsset; struct path; struct task_struct; struct inode; @@ -19,7 +19,7 @@ struct proc_ns_operations { int type; struct ns_common *(*get)(struct task_struct *task); void (*put)(struct ns_common *ns); - int (*install)(struct nsproxy *nsproxy, struct ns_common *ns); + int (*install)(struct nsset *nsset, struct ns_common *ns); struct user_namespace *(*owner)(struct ns_common *ns); struct ns_common *(*get_parent)(struct ns_common *ns); } __randomize_layout; diff --git a/ipc/namespace.c b/ipc/namespace.c index b3ca1476ca5118..fdc3b5f3f53aa7 100644 --- a/ipc/namespace.c +++ b/ipc/namespace.c @@ -177,15 +177,14 @@ static void ipcns_put(struct ns_common *ns) return put_ipc_ns(to_ipc_ns(ns)); } -static int ipcns_install(struct nsproxy *nsproxy, struct ns_common *new) +static int ipcns_install(struct nsset *nsset, struct ns_common *new) { + struct nsproxy *nsproxy = nsset->nsproxy; struct ipc_namespace *ns = to_ipc_ns(new); if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) || - !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) + !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN)) return -EPERM; - /* Ditch state from the old ipc namespace */ - exit_sem(current); put_ipc_ns(nsproxy->ipc_ns); nsproxy->ipc_ns = get_ipc_ns(ns); return 0; diff --git a/kernel/cgroup/namespace.c b/kernel/cgroup/namespace.c index b05f1dd58a6220..812a61afd538a1 100644 --- a/kernel/cgroup/namespace.c +++ b/kernel/cgroup/namespace.c @@ -95,11 +95,12 @@ static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns) return container_of(ns, struct cgroup_namespace, ns); } -static int cgroupns_install(struct nsproxy *nsproxy, struct ns_common *ns) +static int cgroupns_install(struct nsset *nsset, struct ns_common *ns) { + struct nsproxy *nsproxy = nsset->nsproxy; struct cgroup_namespace *cgroup_ns = to_cg_ns(ns); - if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN) || + if (!ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN) || !ns_capable(cgroup_ns->user_ns, CAP_SYS_ADMIN)) return -EPERM; diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index ed9882108cd28f..b7954fd6047538 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -257,12 +258,79 @@ void exit_task_namespaces(struct task_struct *p) switch_task_namespaces(p, NULL); } +static void put_nsset(struct nsset *nsset) +{ + unsigned flags = nsset->flags; + + if (flags & CLONE_NEWUSER) + put_cred(nsset_cred(nsset)); + if (nsset->nsproxy) + free_nsproxy(nsset->nsproxy); +} + +static int prepare_nsset(int nstype, 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 (nstype == CLONE_NEWUSER) + nsset->cred = prepare_creds(); + else + nsset->cred = current_cred(); + if (!nsset->cred) + goto out; + + if (nstype == CLONE_NEWNS) + nsset->fs = me->fs; + + nsset->flags = nstype; + return 0; + +out: + put_nsset(nsset); + return -ENOMEM; +} + +/* + * 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. + */ +static void commit_nsset(struct nsset *nsset) +{ + unsigned flags = nsset->flags; + struct task_struct *me = current; + +#ifdef CONFIG_USER_NS + if (flags & CLONE_NEWUSER) { + /* transfer ownership */ + commit_creds(nsset_cred(nsset)); + nsset->cred = NULL; + } +#endif + +#ifdef CONFIG_IPC_NS + if (flags & CLONE_NEWIPC) + exit_sem(me); +#endif + + /* transfer ownership */ + switch_task_namespaces(me, nsset->nsproxy); + nsset->nsproxy = NULL; +} + SYSCALL_DEFINE2(setns, int, fd, int, nstype) { - struct task_struct *tsk = current; - struct nsproxy *new_nsproxy; struct file *file; struct ns_common *ns; + struct nsset nsset = {}; int err; file = proc_ns_fget(fd); @@ -274,20 +342,16 @@ SYSCALL_DEFINE2(setns, int, fd, int, nstype) if (nstype && (ns->ops->type != nstype)) goto out; - new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs); - if (IS_ERR(new_nsproxy)) { - err = PTR_ERR(new_nsproxy); + err = prepare_nsset(ns->ops->type, &nsset); + if (err) goto out; - } - err = ns->ops->install(new_nsproxy, ns); - if (err) { - free_nsproxy(new_nsproxy); - goto out; + err = ns->ops->install(&nsset, ns); + if (!err) { + commit_nsset(&nsset); + perf_event_namespaces(current); } - switch_task_namespaces(tsk, new_nsproxy); - - perf_event_namespaces(tsk); + put_nsset(&nsset); out: fput(file); return err; diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 01f8ba32cc0c7f..11db2bdbb41e56 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -378,13 +378,14 @@ static void pidns_put(struct ns_common *ns) put_pid_ns(to_pid_ns(ns)); } -static int pidns_install(struct nsproxy *nsproxy, struct ns_common *ns) +static int pidns_install(struct nsset *nsset, struct ns_common *ns) { + struct nsproxy *nsproxy = nsset->nsproxy; struct pid_namespace *active = task_active_pid_ns(current); struct pid_namespace *ancestor, *new = to_pid_ns(ns); if (!ns_capable(new->user_ns, CAP_SYS_ADMIN) || - !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) + !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN)) return -EPERM; /* diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c index 53bce347cd50bc..5d9fc22d836a08 100644 --- a/kernel/time/namespace.c +++ b/kernel/time/namespace.c @@ -280,8 +280,9 @@ static void timens_put(struct ns_common *ns) put_time_ns(to_time_ns(ns)); } -static int timens_install(struct nsproxy *nsproxy, struct ns_common *new) +static int timens_install(struct nsset *nsset, struct ns_common *new) { + struct nsproxy *nsproxy = nsset->nsproxy; struct time_namespace *ns = to_time_ns(new); int err; @@ -289,7 +290,7 @@ static int timens_install(struct nsproxy *nsproxy, struct ns_common *new) return -EUSERS; if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) || - !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) + !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN)) return -EPERM; timens_set_vvar_page(current, ns); diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 8eadadc478f9aa..87804e0371fe19 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -1253,7 +1253,7 @@ static void userns_put(struct ns_common *ns) put_user_ns(to_user_ns(ns)); } -static int userns_install(struct nsproxy *nsproxy, struct ns_common *ns) +static int userns_install(struct nsset *nsset, struct ns_common *ns) { struct user_namespace *user_ns = to_user_ns(ns); struct cred *cred; @@ -1274,14 +1274,14 @@ static int userns_install(struct nsproxy *nsproxy, struct ns_common *ns) if (!ns_capable(user_ns, CAP_SYS_ADMIN)) return -EPERM; - cred = prepare_creds(); + cred = nsset_cred(nsset); if (!cred) - return -ENOMEM; + return -EINVAL; put_user_ns(cred->user_ns); set_cred_user_ns(cred, get_user_ns(user_ns)); - return commit_creds(cred); + return 0; } struct ns_common *ns_get_owner(struct ns_common *ns) diff --git a/kernel/utsname.c b/kernel/utsname.c index f0e4911930092f..e488d0e2ab457b 100644 --- a/kernel/utsname.c +++ b/kernel/utsname.c @@ -140,12 +140,13 @@ static void utsns_put(struct ns_common *ns) put_uts_ns(to_uts_ns(ns)); } -static int utsns_install(struct nsproxy *nsproxy, struct ns_common *new) +static int utsns_install(struct nsset *nsset, struct ns_common *new) { + struct nsproxy *nsproxy = nsset->nsproxy; struct uts_namespace *ns = to_uts_ns(new); if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) || - !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) + !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN)) return -EPERM; get_uts_ns(ns); diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 190ca66a383b78..dcd61aca343eca 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -1353,12 +1353,13 @@ static void netns_put(struct ns_common *ns) put_net(to_net_ns(ns)); } -static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns) +static int netns_install(struct nsset *nsset, struct ns_common *ns) { + struct nsproxy *nsproxy = nsset->nsproxy; struct net *net = to_net_ns(ns); if (!ns_capable(net->user_ns, CAP_SYS_ADMIN) || - !ns_capable(current_user_ns(), CAP_SYS_ADMIN)) + !ns_capable(nsset->cred->user_ns, CAP_SYS_ADMIN)) return -EPERM; put_net(nsproxy->net_ns); From 303cc571d107b3641d6487061b748e70ffe15ce4 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Tue, 5 May 2020 16:04:31 +0200 Subject: [PATCH 2/3] nsproxy: attach to namespaces via pidfds For quite a while we have been thinking about using pidfds to attach to namespaces. This patchset has existed for about a year already but we've wanted to wait to see how the general api would be received and adopted. Now that more and more programs in userspace have started using pidfds for process management it's time to send this one out. This patch makes it possible to use pidfds to attach to the namespaces of another process, i.e. they can be passed as the first argument to the setns() syscall. When only a single namespace type is specified the semantics are equivalent to passing an nsfd. That means setns(nsfd, CLONE_NEWNET) equals setns(pidfd, CLONE_NEWNET). However, when a pidfd is passed, multiple namespace flags can be specified in the second setns() argument and setns() will attach the caller to all the specified namespaces all at once or to none of them. Specifying 0 is not valid together with a pidfd. Here are just two obvious examples: setns(pidfd, CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWNET); setns(pidfd, CLONE_NEWUSER); Allowing to also attach subsets of namespaces supports various use-cases where callers setns to a subset of namespaces to retain privilege, perform an action and then re-attach another subset of namespaces. If the need arises, as Eric suggested, we can extend this patchset to assume even more context than just attaching all namespaces. His suggestion specifically was about assuming the process' root directory when setns(pidfd, 0) or setns(pidfd, SETNS_PIDFD) is specified. For now, just keep it flexible in terms of supporting subsets of namespaces but let's wait until we have users asking for even more context to be assumed. At that point we can add an extension. The obvious example where this is useful is a standard container manager interacting with a running container: pushing and pulling files or directories, injecting mounts, attaching/execing any kind of process, managing network devices all these operations require attaching to all or at least multiple namespaces at the same time. Given that nowadays most containers are spawned with all namespaces enabled we're currently looking at at least 14 syscalls, 7 to open the /proc//ns/ nsfds, another 7 to actually perform the namespace switch. With time namespaces we're looking at about 16 syscalls. (We could amortize the first 7 or 8 syscalls for opening the nsfds by stashing them in each container's monitor process but that would mean we need to send around those file descriptors through unix sockets everytime we want to interact with the container or keep on-disk state. Even in scenarios where a caller wants to join a particular namespace in a particular order callers still profit from batching other namespaces. That mostly applies to the user namespace but all container runtimes I found join the user namespace first no matter if it privileges or deprivileges the container similar to how unshare behaves.) With pidfds this becomes a single syscall no matter how many namespaces are supposed to be attached to. A decently designed, large-scale container manager usually isn't the parent of any of the containers it spawns so the containers don't die when it crashes or needs to update or reinitialize. This means that for the manager to interact with containers through pids is inherently racy especially on systems where the maximum pid number is not significicantly bumped. This is even more problematic since we often spawn and manage thousands or ten-thousands of containers. Interacting with a container through a pid thus can become risky quite quickly. Especially since we allow for an administrator to enable advanced features such as syscall interception where we're performing syscalls in lieu of the container. In all of those cases we use pidfds if they are available and we pass them around as stable references. Using them to setns() to the target process' namespaces is as reliable as using nsfds. Either the target process is already dead and we get ESRCH or we manage to attach to its namespaces but we can't accidently attach to another process' namespaces. So pidfds lend themselves to be used with this api. The other main advantage is that with this change the pidfd becomes the only relevant token for most container interactions and it's the only token we need to create and send around. Apart from significiantly reducing the number of syscalls from double digit to single digit which is a decent reason post-spectre/meltdown this also allows to switch to a set of namespaces atomically, i.e. either attaching to all the specified namespaces succeeds or we fail. If we fail we haven't changed a single namespace. There are currently three namespaces that can fail (other than for ENOMEM which really is not very interesting since we then have other problems anyway) for non-trivial reasons, user, mount, and pid namespaces. We can fail to attach to a pid namespace if it is not our current active pid namespace or a descendant of it. We can fail to attach to a user namespace because we are multi-threaded or because our current mount namespace shares filesystem state with other tasks, or because we're trying to setns() to the same user namespace, i.e. the target task has the same user namespace as we do. We can fail to attach to a mount namespace because it shares filesystem state with other tasks or because we fail to lookup the new root for the new mount namespace. In most non-pathological scenarios these issues can be somewhat mitigated. But there are cases where we're half-attached to some namespace and failing to attach to another one. I've talked about some of these problem during the hallway track (something only the pre-COVID-19 generation will remember) of Plumbers in Los Angeles in 2018(?). Even if all these issues could be avoided with super careful userspace coding it would be nicer to have this done in-kernel. Pidfds seem to lend themselves nicely for this. The other neat thing about this is that setns() becomes an actual counterpart to the namespace bits of unshare(). Signed-off-by: Christian Brauner Reviewed-by: Serge Hallyn Cc: Eric W. Biederman Cc: Serge Hallyn Cc: Jann Horn Cc: Michael Kerrisk Cc: Aleksa Sarai Link: https://lore.kernel.org/r/20200505140432.181565-3-christian.brauner@ubuntu.com --- fs/namespace.c | 5 + fs/nsfs.c | 5 + include/linux/mnt_namespace.h | 1 + include/linux/proc_fs.h | 2 + kernel/nsproxy.c | 229 +++++++++++++++++++++++++++++++--- 5 files changed, 226 insertions(+), 16 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 62899fad4a0404..be99e80e3c7c4e 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1733,6 +1733,11 @@ static struct mnt_namespace *to_mnt_ns(struct ns_common *ns) return container_of(ns, struct mnt_namespace, ns); } +struct ns_common *from_mnt_ns(struct mnt_namespace *mnt) +{ + return &mnt->ns; +} + static bool mnt_ns_loop(struct dentry *dentry) { /* Could bind mounting the mount namespace inode cause a diff --git a/fs/nsfs.c b/fs/nsfs.c index 4f1205725cfef0..800c1d0eb0d026 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -229,6 +229,11 @@ int ns_get_name(char *buf, size_t size, struct task_struct *task, return res; } +bool proc_ns_file(const struct file *file) +{ + return file->f_op == &ns_file_operations; +} + struct file *proc_ns_fget(int fd) { struct file *file; diff --git a/include/linux/mnt_namespace.h b/include/linux/mnt_namespace.h index 007cfa52efb230..8f882f5881e879 100644 --- a/include/linux/mnt_namespace.h +++ b/include/linux/mnt_namespace.h @@ -11,6 +11,7 @@ struct ns_common; extern struct mnt_namespace *copy_mnt_ns(unsigned long, struct mnt_namespace *, struct user_namespace *, struct fs_struct *); extern void put_mnt_ns(struct mnt_namespace *ns); +extern struct ns_common *from_mnt_ns(struct mnt_namespace *); extern const struct file_operations proc_mounts_operations; extern const struct file_operations proc_mountinfo_operations; diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 45c05fd9c99dc6..0cfc44d7ac743e 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -179,4 +179,6 @@ static inline struct pid_namespace *proc_pid_ns(const struct inode *inode) return inode->i_sb->s_fs_info; } +bool proc_ns_file(const struct file *file); + #endif /* _LINUX_PROC_FS_H */ diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index b7954fd6047538..b03df67621d01f 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -258,17 +259,58 @@ void exit_task_namespaces(struct task_struct *p) switch_task_namespaces(p, NULL); } +static int check_setns_flags(unsigned long flags) +{ + if (!flags || (flags & ~(CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC | + CLONE_NEWNET | 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 + + 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(int nstype, struct nsset *nsset) +static int prepare_nsset(unsigned flags, struct nsset *nsset) { struct task_struct *me = current; @@ -276,17 +318,23 @@ static int prepare_nsset(int nstype, struct nsset *nsset) if (IS_ERR(nsset->nsproxy)) return PTR_ERR(nsset->nsproxy); - if (nstype == CLONE_NEWUSER) + if (flags & CLONE_NEWUSER) nsset->cred = prepare_creds(); else nsset->cred = current_cred(); if (!nsset->cred) goto out; - if (nstype == CLONE_NEWNS) + /* 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 = nstype; + nsset->flags = flags; return 0; out: @@ -294,6 +342,138 @@ static int prepare_nsset(int nstype, struct 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 + +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 @@ -316,6 +496,12 @@ static void commit_nsset(struct nsset *nsset) } #endif + /* We only need to commit if we have used a temporary fs_struct. */ + if ((flags & CLONE_NEWNS) && (flags & ~CLONE_NEWNS)) { + set_fs_root(me->fs, &nsset->fs->root); + set_fs_pwd(me->fs, &nsset->fs->pwd); + } + #ifdef CONFIG_IPC_NS if (flags & CLONE_NEWIPC) exit_sem(me); @@ -326,27 +512,38 @@ static void commit_nsset(struct nsset *nsset) nsset->nsproxy = NULL; } -SYSCALL_DEFINE2(setns, int, fd, int, nstype) +SYSCALL_DEFINE2(setns, int, fd, int, flags) { struct file *file; - struct ns_common *ns; + struct ns_common *ns = NULL; struct nsset nsset = {}; - int err; - - file = proc_ns_fget(fd); - if (IS_ERR(file)) - return PTR_ERR(file); + int err = 0; - err = -EINVAL; - ns = get_proc_ns(file_inode(file)); - if (nstype && (ns->ops->type != nstype)) + file = fget(fd); + if (!file) + return -EBADF; + + if (proc_ns_file(file)) { + ns = get_proc_ns(file_inode(file)); + if (flags && (ns->ops->type != flags)) + err = -EINVAL; + flags = ns->ops->type; + } else if (!IS_ERR(pidfd_pid(file))) { + err = check_setns_flags(flags); + } else { + err = -EBADF; + } + if (err) goto out; - err = prepare_nsset(ns->ops->type, &nsset); + err = prepare_nsset(flags, &nsset); if (err) goto out; - err = ns->ops->install(&nsset, ns); + if (proc_ns_file(file)) + err = validate_ns(&nsset, ns); + else + err = validate_nsset(&nsset, file->private_data); if (!err) { commit_nsset(&nsset); perf_event_namespaces(current); From 2b40c5db73e239531ea54991087f4edc07fbb08e Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Tue, 5 May 2020 16:04:32 +0200 Subject: [PATCH 3/3] selftests/pidfd: add pidfd setns tests This is basically a test-suite for setns() and as of now contains: - test that we can't pass garbage flags - test that we can't attach to the namespaces of task that has already exited - test that we can incrementally setns into all namespaces of a target task using a pidfd - test that we can setns atomically into all namespaces of a target task - test that we can't cross setns into a user namespace outside of our user namespace hierarchy - test that we can't setns into namespaces owned by user namespaces over which we are not privileged Signed-off-by: Christian Brauner Link: https://lore.kernel.org/r/20200505140432.181565-4-christian.brauner@ubuntu.com --- tools/testing/selftests/pidfd/.gitignore | 1 + tools/testing/selftests/pidfd/Makefile | 3 +- tools/testing/selftests/pidfd/config | 6 + .../selftests/pidfd/pidfd_setns_test.c | 473 ++++++++++++++++++ 4 files changed, 482 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/pidfd/config create mode 100644 tools/testing/selftests/pidfd/pidfd_setns_test.c diff --git a/tools/testing/selftests/pidfd/.gitignore b/tools/testing/selftests/pidfd/.gitignore index 2d4db5afb142de..973198a3ec3d52 100644 --- a/tools/testing/selftests/pidfd/.gitignore +++ b/tools/testing/selftests/pidfd/.gitignore @@ -5,3 +5,4 @@ pidfd_test pidfd_wait pidfd_fdinfo_test pidfd_getfd_test +pidfd_setns_test diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile index 75a545861375ca..f4a2f28f926bb5 100644 --- a/tools/testing/selftests/pidfd/Makefile +++ b/tools/testing/selftests/pidfd/Makefile @@ -1,7 +1,8 @@ # SPDX-License-Identifier: GPL-2.0-only CFLAGS += -g -I../../../../usr/include/ -pthread -TEST_GEN_PROGS := pidfd_test pidfd_fdinfo_test pidfd_open_test pidfd_poll_test pidfd_wait pidfd_getfd_test +TEST_GEN_PROGS := pidfd_test pidfd_fdinfo_test pidfd_open_test \ + pidfd_poll_test pidfd_wait pidfd_getfd_test pidfd_setns_test include ../lib.mk diff --git a/tools/testing/selftests/pidfd/config b/tools/testing/selftests/pidfd/config new file mode 100644 index 00000000000000..bb11de90c0c9ed --- /dev/null +++ b/tools/testing/selftests/pidfd/config @@ -0,0 +1,6 @@ +CONFIG_UTS_NS=y +CONFIG_IPC_NS=y +CONFIG_USER_NS=y +CONFIG_PID_NS=y +CONFIG_NET_NS=y +CONFIG_CGROUPS=y diff --git a/tools/testing/selftests/pidfd/pidfd_setns_test.c b/tools/testing/selftests/pidfd/pidfd_setns_test.c new file mode 100644 index 00000000000000..133ec5b6cda8b7 --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_setns_test.c @@ -0,0 +1,473 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "pidfd.h" +#include "../clone3/clone3_selftests.h" +#include "../kselftest.h" +#include "../kselftest_harness.h" + +enum { + PIDFD_NS_USER, + PIDFD_NS_MNT, + PIDFD_NS_PID, + PIDFD_NS_UTS, + PIDFD_NS_IPC, + PIDFD_NS_NET, + PIDFD_NS_CGROUP, + PIDFD_NS_PIDCLD, + PIDFD_NS_MAX +}; + +const struct ns_info { + const char *name; + int flag; +} ns_info[] = { + [PIDFD_NS_USER] = { "user", CLONE_NEWUSER, }, + [PIDFD_NS_MNT] = { "mnt", CLONE_NEWNS, }, + [PIDFD_NS_PID] = { "pid", CLONE_NEWPID, }, + [PIDFD_NS_UTS] = { "uts", CLONE_NEWUTS, }, + [PIDFD_NS_IPC] = { "ipc", CLONE_NEWIPC, }, + [PIDFD_NS_NET] = { "net", CLONE_NEWNET, }, + [PIDFD_NS_CGROUP] = { "cgroup", CLONE_NEWCGROUP, }, + [PIDFD_NS_PIDCLD] = { "pid_for_children", 0, }, +}; + +FIXTURE(current_nsset) +{ + pid_t pid; + int pidfd; + int nsfds[PIDFD_NS_MAX]; + + pid_t child_pid_exited; + int child_pidfd_exited; + + pid_t child_pid1; + int child_pidfd1; + int child_nsfds1[PIDFD_NS_MAX]; + + pid_t child_pid2; + int child_pidfd2; + int child_nsfds2[PIDFD_NS_MAX]; +}; + +static int sys_waitid(int which, pid_t pid, int options) +{ + return syscall(__NR_waitid, which, pid, NULL, options, NULL); +} + +pid_t create_child(int *pidfd, unsigned flags) +{ + struct clone_args args = { + .flags = CLONE_PIDFD | flags, + .exit_signal = SIGCHLD, + .pidfd = ptr_to_u64(pidfd), + }; + + return sys_clone3(&args, sizeof(struct clone_args)); +} + +FIXTURE_SETUP(current_nsset) +{ + int i, proc_fd, ret; + + for (i = 0; i < PIDFD_NS_MAX; i++) { + self->nsfds[i] = -EBADF; + self->child_nsfds1[i] = -EBADF; + self->child_nsfds2[i] = -EBADF; + } + + proc_fd = open("/proc/self/ns", O_DIRECTORY | O_CLOEXEC); + ASSERT_GE(proc_fd, 0) { + TH_LOG("%m - Failed to open /proc/self/ns"); + } + + self->pid = getpid(); + for (i = 0; i < PIDFD_NS_MAX; i++) { + const struct ns_info *info = &ns_info[i]; + self->nsfds[i] = openat(proc_fd, info->name, O_RDONLY | O_CLOEXEC); + if (self->nsfds[i] < 0) { + EXPECT_EQ(errno, ENOENT) { + TH_LOG("%m - Failed to open %s namespace for process %d", + info->name, self->pid); + } + } + } + + self->pidfd = sys_pidfd_open(self->pid, 0); + EXPECT_GT(self->pidfd, 0) { + TH_LOG("%m - Failed to open pidfd for process %d", self->pid); + } + + /* Create task that exits right away. */ + self->child_pid_exited = create_child(&self->child_pidfd_exited, + CLONE_NEWUSER | CLONE_NEWNET); + EXPECT_GT(self->child_pid_exited, 0); + + if (self->child_pid_exited == 0) + _exit(EXIT_SUCCESS); + + ASSERT_EQ(sys_waitid(P_PID, self->child_pid_exited, WEXITED | WNOWAIT), 0); + + self->pidfd = sys_pidfd_open(self->pid, 0); + EXPECT_GE(self->pidfd, 0) { + TH_LOG("%m - Failed to open pidfd for process %d", self->pid); + } + + /* Create tasks that will be stopped. */ + self->child_pid1 = create_child(&self->child_pidfd1, + CLONE_NEWUSER | CLONE_NEWNS | + CLONE_NEWCGROUP | CLONE_NEWIPC | + CLONE_NEWUTS | CLONE_NEWPID | + CLONE_NEWNET); + EXPECT_GE(self->child_pid1, 0); + + if (self->child_pid1 == 0) { + pause(); + _exit(EXIT_SUCCESS); + } + + self->child_pid2 = create_child(&self->child_pidfd2, + CLONE_NEWUSER | CLONE_NEWNS | + CLONE_NEWCGROUP | CLONE_NEWIPC | + CLONE_NEWUTS | CLONE_NEWPID | + CLONE_NEWNET); + EXPECT_GE(self->child_pid2, 0); + + if (self->child_pid2 == 0) { + pause(); + _exit(EXIT_SUCCESS); + } + + for (i = 0; i < PIDFD_NS_MAX; i++) { + char p[100]; + + const struct ns_info *info = &ns_info[i]; + + self->nsfds[i] = openat(proc_fd, info->name, O_RDONLY | O_CLOEXEC); + if (self->nsfds[i] < 0) { + EXPECT_EQ(errno, ENOENT) { + TH_LOG("%m - Failed to open %s namespace for process %d", + info->name, self->pid); + } + } + + ret = snprintf(p, sizeof(p), "/proc/%d/ns/%s", + self->child_pid1, info->name); + EXPECT_GT(ret, 0); + EXPECT_LT(ret, sizeof(p)); + + self->child_nsfds1[i] = open(p, O_RDONLY | O_CLOEXEC); + if (self->child_nsfds1[i] < 0) { + EXPECT_EQ(errno, ENOENT) { + TH_LOG("%m - Failed to open %s namespace for process %d", + info->name, self->child_pid1); + } + } + + ret = snprintf(p, sizeof(p), "/proc/%d/ns/%s", + self->child_pid2, info->name); + EXPECT_GT(ret, 0); + EXPECT_LT(ret, sizeof(p)); + + self->child_nsfds2[i] = open(p, O_RDONLY | O_CLOEXEC); + if (self->child_nsfds2[i] < 0) { + EXPECT_EQ(errno, ENOENT) { + TH_LOG("%m - Failed to open %s namespace for process %d", + info->name, self->child_pid1); + } + } + } + + close(proc_fd); +} + +FIXTURE_TEARDOWN(current_nsset) +{ + int i; + + ASSERT_EQ(sys_pidfd_send_signal(self->child_pidfd1, + SIGKILL, NULL, 0), 0); + ASSERT_EQ(sys_pidfd_send_signal(self->child_pidfd2, + SIGKILL, NULL, 0), 0); + + for (i = 0; i < PIDFD_NS_MAX; i++) { + if (self->nsfds[i] >= 0) + close(self->nsfds[i]); + if (self->child_nsfds1[i] >= 0) + close(self->child_nsfds1[i]); + if (self->child_nsfds2[i] >= 0) + close(self->child_nsfds2[i]); + } + + if (self->child_pidfd1 >= 0) + EXPECT_EQ(0, close(self->child_pidfd1)); + if (self->child_pidfd2 >= 0) + EXPECT_EQ(0, close(self->child_pidfd2)); + ASSERT_EQ(sys_waitid(P_PID, self->child_pid_exited, WEXITED), 0); + ASSERT_EQ(sys_waitid(P_PID, self->child_pid1, WEXITED), 0); + ASSERT_EQ(sys_waitid(P_PID, self->child_pid2, WEXITED), 0); +} + +static int preserve_ns(const int pid, const char *ns) +{ + int ret; + char path[50]; + + ret = snprintf(path, sizeof(path), "/proc/%d/ns/%s", pid, ns); + if (ret < 0 || (size_t)ret >= sizeof(path)) + return -EIO; + + return open(path, O_RDONLY | O_CLOEXEC); +} + +static int in_same_namespace(int ns_fd1, pid_t pid2, const char *ns) +{ + int ns_fd2 = -EBADF; + int ret = -1; + struct stat ns_st1, ns_st2; + + ret = fstat(ns_fd1, &ns_st1); + if (ret < 0) + return -1; + + ns_fd2 = preserve_ns(pid2, ns); + if (ns_fd2 < 0) + return -1; + + ret = fstat(ns_fd2, &ns_st2); + close(ns_fd2); + if (ret < 0) + return -1; + + /* processes are in the same namespace */ + if ((ns_st1.st_dev == ns_st2.st_dev) && + (ns_st1.st_ino == ns_st2.st_ino)) + return 1; + + /* processes are in different namespaces */ + return 0; +} + +/* Test that we can't pass garbage to the kernel. */ +TEST_F(current_nsset, invalid_flags) +{ + ASSERT_NE(setns(self->pidfd, 0), 0); + EXPECT_EQ(errno, EINVAL); + + ASSERT_NE(setns(self->pidfd, -1), 0); + EXPECT_EQ(errno, EINVAL); + + ASSERT_NE(setns(self->pidfd, CLONE_VM), 0); + EXPECT_EQ(errno, EINVAL); + + ASSERT_NE(setns(self->pidfd, CLONE_NEWUSER | CLONE_VM), 0); + EXPECT_EQ(errno, EINVAL); +} + +/* Test that we can't attach to a task that has already exited. */ +TEST_F(current_nsset, pidfd_exited_child) +{ + int i; + pid_t pid; + + ASSERT_NE(setns(self->child_pidfd_exited, CLONE_NEWUSER | CLONE_NEWNET), + 0); + EXPECT_EQ(errno, ESRCH); + + pid = getpid(); + for (i = 0; i < PIDFD_NS_MAX; i++) { + const struct ns_info *info = &ns_info[i]; + /* Verify that we haven't changed any namespaces. */ + if (self->nsfds[i] >= 0) + ASSERT_EQ(in_same_namespace(self->nsfds[i], pid, info->name), 1); + } +} + +TEST_F(current_nsset, pidfd_incremental_setns) +{ + int i; + pid_t pid; + + pid = getpid(); + for (i = 0; i < PIDFD_NS_MAX; i++) { + const struct ns_info *info = &ns_info[i]; + int nsfd; + + if (self->child_nsfds1[i] < 0) + continue; + + if (info->flag) { + ASSERT_EQ(setns(self->child_pidfd1, info->flag), 0) { + TH_LOG("%m - Failed to setns to %s namespace of %d via pidfd %d", + info->name, self->child_pid1, + self->child_pidfd1); + } + } + + /* Verify that we have changed to the correct namespaces. */ + if (info->flag == CLONE_NEWPID) + nsfd = self->nsfds[i]; + else + nsfd = self->child_nsfds1[i]; + ASSERT_EQ(in_same_namespace(nsfd, pid, info->name), 1) { + TH_LOG("setns failed to place us correctly into %s namespace of %d via pidfd %d", + info->name, self->child_pid1, + self->child_pidfd1); + } + TH_LOG("Managed to correctly setns to %s namespace of %d via pidfd %d", + info->name, self->child_pid1, self->child_pidfd1); + } +} + +TEST_F(current_nsset, nsfd_incremental_setns) +{ + int i; + pid_t pid; + + pid = getpid(); + for (i = 0; i < PIDFD_NS_MAX; i++) { + const struct ns_info *info = &ns_info[i]; + int nsfd; + + if (self->child_nsfds1[i] < 0) + continue; + + if (info->flag) { + ASSERT_EQ(setns(self->child_nsfds1[i], info->flag), 0) { + TH_LOG("%m - Failed to setns to %s namespace of %d via nsfd %d", + info->name, self->child_pid1, + self->child_nsfds1[i]); + } + } + + /* Verify that we have changed to the correct namespaces. */ + if (info->flag == CLONE_NEWPID) + nsfd = self->nsfds[i]; + else + nsfd = self->child_nsfds1[i]; + ASSERT_EQ(in_same_namespace(nsfd, pid, info->name), 1) { + TH_LOG("setns failed to place us correctly into %s namespace of %d via nsfd %d", + info->name, self->child_pid1, + self->child_nsfds1[i]); + } + TH_LOG("Managed to correctly setns to %s namespace of %d via nsfd %d", + info->name, self->child_pid1, self->child_nsfds1[i]); + } +} + +TEST_F(current_nsset, pidfd_one_shot_setns) +{ + unsigned flags = 0; + int i; + pid_t pid; + + for (i = 0; i < PIDFD_NS_MAX; i++) { + const struct ns_info *info = &ns_info[i]; + + if (self->child_nsfds1[i] < 0) + continue; + + flags |= info->flag; + TH_LOG("Adding %s namespace of %d to list of namespaces to attach to", + info->name, self->child_pid1); + } + + ASSERT_EQ(setns(self->child_pidfd1, flags), 0) { + TH_LOG("%m - Failed to setns to namespaces of %d", + self->child_pid1); + } + + pid = getpid(); + for (i = 0; i < PIDFD_NS_MAX; i++) { + const struct ns_info *info = &ns_info[i]; + int nsfd; + + if (self->child_nsfds1[i] < 0) + continue; + + /* Verify that we have changed to the correct namespaces. */ + if (info->flag == CLONE_NEWPID) + nsfd = self->nsfds[i]; + else + nsfd = self->child_nsfds1[i]; + ASSERT_EQ(in_same_namespace(nsfd, pid, info->name), 1) { + TH_LOG("setns failed to place us correctly into %s namespace of %d", + info->name, self->child_pid1); + } + TH_LOG("Managed to correctly setns to %s namespace of %d", + info->name, self->child_pid1); + } +} + +TEST_F(current_nsset, no_foul_play) +{ + unsigned flags = 0; + int i; + + for (i = 0; i < PIDFD_NS_MAX; i++) { + const struct ns_info *info = &ns_info[i]; + + if (self->child_nsfds1[i] < 0) + continue; + + flags |= info->flag; + if (info->flag) /* No use logging pid_for_children. */ + TH_LOG("Adding %s namespace of %d to list of namespaces to attach to", + info->name, self->child_pid1); + } + + ASSERT_EQ(setns(self->child_pidfd1, flags), 0) { + TH_LOG("%m - Failed to setns to namespaces of %d vid pidfd %d", + self->child_pid1, self->child_pidfd1); + } + + /* + * Can't setns to a user namespace outside of our hierarchy since we + * don't have caps in there and didn't create it. That means that under + * no circumstances should we be able to setns to any of the other + * ones since they aren't owned by our user namespace. + */ + for (i = 0; i < PIDFD_NS_MAX; i++) { + const struct ns_info *info = &ns_info[i]; + + if (self->child_nsfds2[i] < 0 || !info->flag) + continue; + + ASSERT_NE(setns(self->child_pidfd2, info->flag), 0) { + TH_LOG("Managed to setns to %s namespace of %d via pidfd %d", + info->name, self->child_pid2, + self->child_pidfd2); + } + TH_LOG("%m - Correctly failed to setns to %s namespace of %d via pidfd %d", + info->name, self->child_pid2, + self->child_pidfd2); + + ASSERT_NE(setns(self->child_nsfds2[i], info->flag), 0) { + TH_LOG("Managed to setns to %s namespace of %d via nsfd %d", + info->name, self->child_pid2, + self->child_nsfds2[i]); + } + TH_LOG("%m - Correctly failed to setns to %s namespace of %d via nsfd %d", + info->name, self->child_pid2, + self->child_nsfds2[i]); + } +} + +TEST_HARNESS_MAIN