diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/fork.c | 19 | ||||
| -rw-r--r-- | kernel/nsproxy.c | 17 |
2 files changed, 30 insertions, 6 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 131ae7bbb0de..9c194fc58736 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2667,6 +2667,16 @@ pid_t kernel_clone(struct kernel_clone_args *args) pid_t nr; /* + * Creating an empty mount namespace implies creating a new mount + * namespace. Set this before copy_process() so that the + * CLONE_NEWNS|CLONE_FS mutual exclusion check works correctly. + */ + if (clone_flags & CLONE_EMPTY_MNTNS) { + clone_flags |= CLONE_NEWNS; + args->flags = clone_flags; + } + + /* * For legacy clone() calls, CLONE_PIDFD uses the parent_tid argument * to return the pidfd. Hence, CLONE_PIDFD and CLONE_PARENT_SETTID are * mutually exclusive. With clone3() CLONE_PIDFD has grown a separate @@ -2944,8 +2954,9 @@ static bool clone3_args_valid(struct kernel_clone_args *kargs) { /* Verify that no unknown flags are passed along. */ if (kargs->flags & - ~(CLONE_LEGACY_FLAGS | CLONE_CLEAR_SIGHAND | CLONE_INTO_CGROUP | - CLONE_AUTOREAP | CLONE_NNP | CLONE_PIDFD_AUTOKILL)) + ~(CLONE_LEGACY_FLAGS | CLONE_CLEAR_SIGHAND | + CLONE_INTO_CGROUP | CLONE_AUTOREAP | CLONE_NNP | + CLONE_PIDFD_AUTOKILL | CLONE_EMPTY_MNTNS)) return false; /* @@ -3096,7 +3107,7 @@ static int check_unshare_flags(unsigned long unshare_flags) { if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_SIGHAND| CLONE_VM|CLONE_FILES|CLONE_SYSVSEM| - CLONE_NS_ALL)) + CLONE_NS_ALL | UNSHARE_EMPTY_MNTNS)) return -EINVAL; /* * Not implemented, but pretend it works if there is nothing @@ -3195,6 +3206,8 @@ int ksys_unshare(unsigned long unshare_flags) /* * If unsharing namespace, must also unshare filesystem information. */ + if (unshare_flags & UNSHARE_EMPTY_MNTNS) + unshare_flags |= CLONE_NEWNS; if (unshare_flags & CLONE_NEWNS) unshare_flags |= CLONE_FS; diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index 63b44ee79847..d9d3d5973bf5 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -96,7 +96,8 @@ static struct nsproxy *create_new_namespaces(u64 flags, if (!new_nsp) return ERR_PTR(-ENOMEM); - new_nsp->mnt_ns = copy_mnt_ns(flags, tsk->nsproxy->mnt_ns, user_ns, new_fs); + 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; @@ -211,16 +212,26 @@ 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; + u64 flags = unshare_flags; int err = 0; - if (!(unshare_flags & (CLONE_NS_ALL & ~CLONE_NEWUSER))) + if (!(flags & (CLONE_NS_ALL & ~CLONE_NEWUSER))) 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, + /* + * Convert the 32-bit UNSHARE_EMPTY_MNTNS (which aliases + * CLONE_PARENT_SETTID) to the unique 64-bit CLONE_EMPTY_MNTNS. + */ + if (flags & UNSHARE_EMPTY_MNTNS) { + flags &= ~(u64)UNSHARE_EMPTY_MNTNS; + flags |= CLONE_EMPTY_MNTNS; + } + + *new_nsp = create_new_namespaces(flags, current, user_ns, new_fs ? new_fs : current->fs); if (IS_ERR(*new_nsp)) { err = PTR_ERR(*new_nsp); |