diff options
author | Eric W. Biederman <ebiederm@xmission.com> | 2012-07-27 04:08:32 (GMT) |
---|---|---|
committer | Eric W. Biederman <ebiederm@xmission.com> | 2012-11-19 13:59:19 (GMT) |
commit | 771b1371686e0a63e938ada28de020b9a0040f55 (patch) | |
tree | 1eb8891f19c43255febe2e801c33cbe7061e9a34 /fs | |
parent | 8823c079ba7136dc1948d6f6dcb5f8022bde438e (diff) | |
download | linux-771b1371686e0a63e938ada28de020b9a0040f55.tar.xz |
vfs: Add a user namespace reference from struct mnt_namespace
This will allow for support for unprivileged mounts in a new user namespace.
Acked-by: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/mount.h | 1 | ||||
-rw-r--r-- | fs/namespace.c | 24 |
2 files changed, 17 insertions, 8 deletions
@@ -6,6 +6,7 @@ struct mnt_namespace { atomic_t count; struct mount * root; struct list_head list; + struct user_namespace *user_ns; u64 seq; /* Sequence number to prevent loops */ wait_queue_head_t poll; int event; diff --git a/fs/namespace.c b/fs/namespace.c index d287e7e..207c7ba 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -12,6 +12,7 @@ #include <linux/export.h> #include <linux/capability.h> #include <linux/mnt_namespace.h> +#include <linux/user_namespace.h> #include <linux/namei.h> #include <linux/security.h> #include <linux/idr.h> @@ -2286,6 +2287,12 @@ dput_out: return retval; } +static void free_mnt_ns(struct mnt_namespace *ns) +{ + put_user_ns(ns->user_ns); + kfree(ns); +} + /* * Assign a sequence number so we can detect when we attempt to bind * mount a reference to an older mount namespace into the current @@ -2295,7 +2302,7 @@ dput_out: */ static atomic64_t mnt_ns_seq = ATOMIC64_INIT(1); -static struct mnt_namespace *alloc_mnt_ns(void) +static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns) { struct mnt_namespace *new_ns; @@ -2308,6 +2315,7 @@ static struct mnt_namespace *alloc_mnt_ns(void) INIT_LIST_HEAD(&new_ns->list); init_waitqueue_head(&new_ns->poll); new_ns->event = 0; + new_ns->user_ns = get_user_ns(user_ns); return new_ns; } @@ -2316,7 +2324,7 @@ static struct mnt_namespace *alloc_mnt_ns(void) * copied from the namespace of the passed in task structure. */ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, - struct fs_struct *fs) + struct user_namespace *user_ns, struct fs_struct *fs) { struct mnt_namespace *new_ns; struct vfsmount *rootmnt = NULL, *pwdmnt = NULL; @@ -2324,7 +2332,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, struct mount *old = mnt_ns->root; struct mount *new; - new_ns = alloc_mnt_ns(); + new_ns = alloc_mnt_ns(user_ns); if (IS_ERR(new_ns)) return new_ns; @@ -2333,7 +2341,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, new = copy_tree(old, old->mnt.mnt_root, CL_COPY_ALL | CL_EXPIRE); if (IS_ERR(new)) { up_write(&namespace_sem); - kfree(new_ns); + free_mnt_ns(new_ns); return ERR_CAST(new); } new_ns->root = new; @@ -2374,7 +2382,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns, } struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns, - struct fs_struct *new_fs) + struct user_namespace *user_ns, struct fs_struct *new_fs) { struct mnt_namespace *new_ns; @@ -2384,7 +2392,7 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns, if (!(flags & CLONE_NEWNS)) return ns; - new_ns = dup_mnt_ns(ns, new_fs); + new_ns = dup_mnt_ns(ns, user_ns, new_fs); put_mnt_ns(ns); return new_ns; @@ -2396,7 +2404,7 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns, */ static struct mnt_namespace *create_mnt_ns(struct vfsmount *m) { - struct mnt_namespace *new_ns = alloc_mnt_ns(); + struct mnt_namespace *new_ns = alloc_mnt_ns(&init_user_ns); if (!IS_ERR(new_ns)) { struct mount *mnt = real_mount(m); mnt->mnt_ns = new_ns; @@ -2682,7 +2690,7 @@ void put_mnt_ns(struct mnt_namespace *ns) br_write_unlock(&vfsmount_lock); up_write(&namespace_sem); release_mounts(&umount_list); - kfree(ns); + free_mnt_ns(ns); } struct vfsmount *kern_mount_data(struct file_system_type *type, void *data) |