Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull user namespace and namespace infrastructure changes from Eric W Biederman:
 "This set of changes starts with a few small enhnacements to the user
  namespace.  reboot support, allowing more arbitrary mappings, and
  support for mounting devpts, ramfs, tmpfs, and mqueuefs as just the
  user namespace root.

  I do my best to document that if you care about limiting your
  unprivileged users that when you have the user namespace support
  enabled you will need to enable memory control groups.

  There is a minor bug fix to prevent overflowing the stack if someone
  creates way too many user namespaces.

  The bulk of the changes are a continuation of the kuid/kgid push down
  work through the filesystems.  These changes make using uids and gids
  typesafe which ensures that these filesystems are safe to use when
  multiple user namespaces are in use.  The filesystems converted for
  3.9 are ceph, 9p, afs, ocfs2, gfs2, ncpfs, nfs, nfsd, and cifs.  The
  changes for these filesystems were a little more involved so I split
  the changes into smaller hopefully obviously correct changes.

  XFS is the only filesystem that remains.  I was hoping I could get
  that in this release so that user namespace support would be enabled
  with an allyesconfig or an allmodconfig but it looks like the xfs
  changes need another couple of days before it they are ready."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (93 commits)
  cifs: Enable building with user namespaces enabled.
  cifs: Convert struct cifs_ses to use a kuid_t and a kgid_t
  cifs: Convert struct cifs_sb_info to use kuids and kgids
  cifs: Modify struct smb_vol to use kuids and kgids
  cifs: Convert struct cifsFileInfo to use a kuid
  cifs: Convert struct cifs_fattr to use kuid and kgids
  cifs: Convert struct tcon_link to use a kuid.
  cifs: Modify struct cifs_unix_set_info_args to hold a kuid_t and a kgid_t
  cifs: Convert from a kuid before printing current_fsuid
  cifs: Use kuids and kgids SID to uid/gid mapping
  cifs: Pass GLOBAL_ROOT_UID and GLOBAL_ROOT_GID to keyring_alloc
  cifs: Use BUILD_BUG_ON to validate uids and gids are the same size
  cifs: Override unmappable incoming uids and gids
  nfsd: Enable building with user namespaces enabled.
  nfsd: Properly compare and initialize kuids and kgids
  nfsd: Store ex_anon_uid and ex_anon_gid as kuids and kgids
  nfsd: Modify nfsd4_cb_sec to use kuids and kgids
  nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion
  nfsd: Convert nfsxdr to use kuids and kgids
  nfsd: Convert nfs3xdr to use kuids and kgids
  ...

4 files changed, 21 insertions, 16 deletions

diff --git a/fs/afs/afs.h b/fs/afs/afs.h
index c548aa346f0d..3c462ff6db63 100644
--- a/fs/afs/afs.h
+++ b/fs/afs/afs.h
@@ -119,8 +119,8 @@ struct afs_file_status {
         u64                     size;           /* file size */
         afs_dataversion_t       data_version;   /* current data version */
         u32                     author;         /* author ID */
-        u32                     owner;          /* owner ID */
-        u32                     group;          /* group ID */
+        kuid_t                  owner;          /* owner ID */
+        kgid_t                  group;          /* group ID */
         afs_access_t            caller_access;  /* access rights for authenticated caller */
         afs_access_t            anon_access;    /* access rights for unauthenticated caller */
         umode_t                 mode;           /* UNIX mode */
@@ -133,13 +133,6 @@ struct afs_file_status {
 /*
  * AFS file status change request
  */
-struct afs_store_status {
-        u32                     mask;           /* which bits of the struct are set */
-        u32                     mtime_client;   /* last time client changed data */
-        u32                     owner;          /* owner ID */
-        u32                     group;          /* group ID */
-        umode_t                 mode;           /* UNIX mode */
-};
 
 #define AFS_SET_MTIME           0x01            /* set the mtime */
 #define AFS_SET_OWNER           0x02            /* set the owner ID */
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index b960ff05ea0b..c2e930ec2888 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -42,6 +42,8 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp,
         umode_t mode;
         u64 data_version, size;
         u32 changed = 0; /* becomes non-zero if ctime-type changes seen */
+        kuid_t owner;
+        kgid_t group;
 
 #define EXTRACT(DST)                            \
         do {                                    \
@@ -56,7 +58,9 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp,
         size = ntohl(*bp++);
         data_version = ntohl(*bp++);
         EXTRACT(status->author);
-        EXTRACT(status->owner);
+        owner = make_kuid(&init_user_ns, ntohl(*bp++));
+        changed |= !uid_eq(owner, status->owner);
+        status->owner = owner;
         EXTRACT(status->caller_access); /* call ticket dependent */
         EXTRACT(status->anon_access);
         EXTRACT(status->mode);
@@ -65,7 +69,9 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp,
         bp++; /* seg size */
         status->mtime_client = ntohl(*bp++);
         status->mtime_server = ntohl(*bp++);
-        EXTRACT(status->group);
+        group = make_kgid(&init_user_ns, ntohl(*bp++));
+        changed |= !gid_eq(group, status->group);
+        status->group = group;
         bp++; /* sync counter */
         data_version |= (u64) ntohl(*bp++) << 32;
         EXTRACT(status->lock_count);
@@ -181,12 +187,12 @@ static void xdr_encode_AFS_StoreStatus(__be32 **_bp, struct iattr *attr)
 
         if (attr->ia_valid & ATTR_UID) {
                 mask |= AFS_SET_OWNER;
-                owner = attr->ia_uid;
+                owner = from_kuid(&init_user_ns, attr->ia_uid);
         }
 
         if (attr->ia_valid & ATTR_GID) {
                 mask |= AFS_SET_GROUP;
-                group = attr->ia_gid;
+                group = from_kgid(&init_user_ns, attr->ia_gid);
         }
 
         if (attr->ia_valid & ATTR_MODE) {
diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 95cffd38239f..789bc253b5f6 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -69,7 +69,7 @@ static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
 
         set_nlink(inode, vnode->status.nlink);
         inode->i_uid            = vnode->status.owner;
-        inode->i_gid            = 0;
+        inode->i_gid            = GLOBAL_ROOT_GID;
         inode->i_size           = vnode->status.size;
         inode->i_ctime.tv_sec   = vnode->status.mtime_server;
         inode->i_ctime.tv_nsec  = 0;
@@ -175,8 +175,8 @@ struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name,
         inode->i_mode           = S_IFDIR | S_IRUGO | S_IXUGO;
         inode->i_op             = &afs_autocell_inode_operations;
         set_nlink(inode, 2);
-        inode->i_uid            = 0;
-        inode->i_gid            = 0;
+        inode->i_uid            = GLOBAL_ROOT_UID;
+        inode->i_gid            = GLOBAL_ROOT_GID;
         inode->i_ctime.tv_sec   = get_seconds();
         inode->i_ctime.tv_nsec  = 0;
         inode->i_atime          = inode->i_mtime = inode->i_ctime;
diff --git a/fs/afs/super.c b/fs/afs/super.c
index 43165009428d..7c31ec399575 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -24,6 +24,8 @@
 #include <linux/parser.h>
 #include <linux/statfs.h>
 #include <linux/sched.h>
+#include <linux/nsproxy.h>
+#include <net/net_namespace.h>
 #include "internal.h"
 
 #define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */
@@ -363,6 +365,10 @@ static struct dentry *afs_mount(struct file_system_type *fs_type,
 
         memset(&params, 0, sizeof(params));
 
+        ret = -EINVAL;
+        if (current->nsproxy->net_ns != &init_net)
+                goto error;
+
         /* parse the options and device name */
         if (options) {
                 ret = afs_parse_options(&params, options, &dev_name);