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
  ...

1 files changed, 27 insertions, 16 deletions

diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index 4d0129203733..a1852e19ed0c 100644
--- a/net/sunrpc/svcauth_unix.c
+++ b/net/sunrpc/svcauth_unix.c
@@ -415,10 +415,15 @@ svcauth_unix_info_release(struct svc_xprt *xpt)
 
 struct unix_gid {
         struct cache_head       h;
-        uid_t                   uid;
+        kuid_t                  uid;
         struct group_info       *gi;
 };
 
+static int unix_gid_hash(kuid_t uid)
+{
+        return hash_long(from_kuid(&init_user_ns, uid), GID_HASHBITS);
+}
+
 static void unix_gid_put(struct kref *kref)
 {
         struct cache_head *item = container_of(kref, struct cache_head, ref);
@@ -433,7 +438,7 @@ static int unix_gid_match(struct cache_head *corig, struct cache_head *cnew)
 {
         struct unix_gid *orig = container_of(corig, struct unix_gid, h);
         struct unix_gid *new = container_of(cnew, struct unix_gid, h);
-        return orig->uid == new->uid;
+        return uid_eq(orig->uid, new->uid);
 }
 static void unix_gid_init(struct cache_head *cnew, struct cache_head *citem)
 {
@@ -465,7 +470,7 @@ static void unix_gid_request(struct cache_detail *cd,
         char tuid[20];
         struct unix_gid *ug = container_of(h, struct unix_gid, h);
 
-        snprintf(tuid, 20, "%u", ug->uid);
+        snprintf(tuid, 20, "%u", from_kuid(&init_user_ns, ug->uid));
         qword_add(bpp, blen, tuid);
         (*bpp)[-1] = '\n';
 }
@@ -475,13 +480,14 @@ static int unix_gid_upcall(struct cache_detail *cd, struct cache_head *h)
         return sunrpc_cache_pipe_upcall(cd, h, unix_gid_request);
 }
 
-static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, uid_t uid);
+static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, kuid_t uid);
 
 static int unix_gid_parse(struct cache_detail *cd,
                         char *mesg, int mlen)
 {
         /* uid expiry Ngid gid0 gid1 ... gidN-1 */
-        int uid;
+        int id;
+        kuid_t uid;
         int gids;
         int rv;
         int i;
@@ -493,9 +499,12 @@ static int unix_gid_parse(struct cache_detail *cd,
                 return -EINVAL;
         mesg[mlen-1] = 0;
 
-        rv = get_int(&mesg, &uid);
+        rv = get_int(&mesg, &id);
         if (rv)
                 return -EINVAL;
+        uid = make_kuid(&init_user_ns, id);
+        if (!uid_valid(uid))
+                return -EINVAL;
         ug.uid = uid;
 
         expiry = get_expiry(&mesg);
@@ -530,7 +539,7 @@ static int unix_gid_parse(struct cache_detail *cd,
                 ug.h.expiry_time = expiry;
                 ch = sunrpc_cache_update(cd,
                                          &ug.h, &ugp->h,
-                                         hash_long(uid, GID_HASHBITS));
+                                         unix_gid_hash(uid));
                 if (!ch)
                         err = -ENOMEM;
                 else {
@@ -549,7 +558,7 @@ static int unix_gid_show(struct seq_file *m,
                          struct cache_detail *cd,
                          struct cache_head *h)
 {
-        struct user_namespace *user_ns = current_user_ns();
+        struct user_namespace *user_ns = &init_user_ns;
         struct unix_gid *ug;
         int i;
         int glen;
@@ -565,7 +574,7 @@ static int unix_gid_show(struct seq_file *m,
         else
                 glen = 0;
 
-        seq_printf(m, "%u %d:", ug->uid, glen);
+        seq_printf(m, "%u %d:", from_kuid_munged(user_ns, ug->uid), glen);
         for (i = 0; i < glen; i++)
                 seq_printf(m, " %d", from_kgid_munged(user_ns, GROUP_AT(ug->gi, i)));
         seq_printf(m, "\n");
@@ -615,20 +624,20 @@ void unix_gid_cache_destroy(struct net *net)
         cache_destroy_net(cd, net);
 }
 
-static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, uid_t uid)
+static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, kuid_t uid)
 {
         struct unix_gid ug;
         struct cache_head *ch;
 
         ug.uid = uid;
-        ch = sunrpc_cache_lookup(cd, &ug.h, hash_long(uid, GID_HASHBITS));
+        ch = sunrpc_cache_lookup(cd, &ug.h, unix_gid_hash(uid));
         if (ch)
                 return container_of(ch, struct unix_gid, h);
         else
                 return NULL;
 }
 
-static struct group_info *unix_gid_find(uid_t uid, struct svc_rqst *rqstp)
+static struct group_info *unix_gid_find(kuid_t uid, struct svc_rqst *rqstp)
 {
         struct unix_gid *ug;
         struct group_info *gi;
@@ -750,8 +759,8 @@ svcauth_null_accept(struct svc_rqst *rqstp, __be32 *authp)
         }
 
         /* Signal that mapping to nobody uid/gid is required */
-        cred->cr_uid = (uid_t) -1;
-        cred->cr_gid = (gid_t) -1;
+        cred->cr_uid = INVALID_UID;
+        cred->cr_gid = INVALID_GID;
         cred->cr_group_info = groups_alloc(0);
         if (cred->cr_group_info == NULL)
                 return SVC_CLOSE; /* kmalloc failure - client must retry */
@@ -812,8 +821,10 @@ svcauth_unix_accept(struct svc_rqst *rqstp, __be32 *authp)
         argv->iov_base = (void*)((__be32*)argv->iov_base + slen);       /* skip machname */
         argv->iov_len -= slen*4;
 
-        cred->cr_uid = svc_getnl(argv);         /* uid */
-        cred->cr_gid = svc_getnl(argv);         /* gid */
+        cred->cr_uid = make_kuid(&init_user_ns, svc_getnl(argv)); /* uid */
+        cred->cr_gid = make_kgid(&init_user_ns, svc_getnl(argv)); /* gid */
+        if (!uid_valid(cred->cr_uid) || !gid_valid(cred->cr_gid))
+                goto badcred;
         slen = svc_getnl(argv);                 /* gids length */
         if (slen > 16 || (len -= (slen + 2)*4) < 0)
                 goto badcred;