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

Pull user namespace changes from Eric Biederman:
 "This is a mostly modest set of changes to enable basic user namespace
  support.  This allows the code to code to compile with user namespaces
  enabled and removes the assumption there is only the initial user
  namespace.  Everything is converted except for the most complex of the
  filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs,
  nfs, ocfs2 and xfs as those patches need a bit more review.

  The strategy is to push kuid_t and kgid_t values are far down into
  subsystems and filesystems as reasonable.  Leaving the make_kuid and
  from_kuid operations to happen at the edge of userspace, as the values
  come off the disk, and as the values come in from the network.
  Letting compile type incompatible compile errors (present when user
  namespaces are enabled) guide me to find the issues.

  The most tricky areas have been the places where we had an implicit
  union of uid and gid values and were storing them in an unsigned int.
  Those places were converted into explicit unions.  I made certain to
  handle those places with simple trivial patches.

  Out of that work I discovered we have generic interfaces for storing
  quota by projid.  I had never heard of the project identifiers before.
  Adding full user namespace support for project identifiers accounts
  for most of the code size growth in my git tree.

  Ultimately there will be work to relax privlige checks from
  "capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing
  root in a user names to do those things that today we only forbid to
  non-root users because it will confuse suid root applications.

  While I was pushing kuid_t and kgid_t changes deep into the audit code
  I made a few other cleanups.  I capitalized on the fact we process
  netlink messages in the context of the message sender.  I removed
  usage of NETLINK_CRED, and started directly using current->tty.

  Some of these patches have also made it into maintainer trees, with no
  problems from identical code from different trees showing up in
  linux-next.

  After reading through all of this code I feel like I might be able to
  win a game of kernel trivial pursuit."

Fix up some fairly trivial conflicts in netfilter uid/git logging code.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits)
  userns: Convert the ufs filesystem to use kuid/kgid where appropriate
  userns: Convert the udf filesystem to use kuid/kgid where appropriate
  userns: Convert ubifs to use kuid/kgid
  userns: Convert squashfs to use kuid/kgid where appropriate
  userns: Convert reiserfs to use kuid and kgid where appropriate
  userns: Convert jfs to use kuid/kgid where appropriate
  userns: Convert jffs2 to use kuid and kgid where appropriate
  userns: Convert hpfs to use kuid and kgid where appropriate
  userns: Convert btrfs to use kuid/kgid where appropriate
  userns: Convert bfs to use kuid/kgid where appropriate
  userns: Convert affs to use kuid/kgid wherwe appropriate
  userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids
  userns: On ia64 deal with current_uid and current_gid being kuid and kgid
  userns: On ppc convert current_uid from a kuid before printing.
  userns: Convert s390 getting uid and gid system calls to use kuid and kgid
  userns: Convert s390 hypfs to use kuid and kgid where appropriate
  userns: Convert binder ipc to use kuids
  userns: Teach security_path_chown to take kuids and kgids
  userns: Add user namespace support to IMA
  userns: Convert EVM to deal with kuids and kgids in it's hmac computation
  ...

1 files changed, 127 insertions, 1 deletions

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 86602316422d..456a6b9fba34 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -19,6 +19,7 @@
 #include <linux/fs.h>
 #include <linux/uaccess.h>
 #include <linux/ctype.h>
+#include <linux/projid.h>
 
 static struct kmem_cache *user_ns_cachep __read_mostly;
 
@@ -295,6 +296,75 @@ gid_t from_kgid_munged(struct user_namespace *targ, kgid_t kgid)
 }
 EXPORT_SYMBOL(from_kgid_munged);
 
+/**
+ *      make_kprojid - Map a user-namespace projid pair into a kprojid.
+ *      @ns:  User namespace that the projid is in
+ *      @projid: Project identifier
+ *
+ *      Maps a user-namespace uid pair into a kernel internal kuid,
+ *      and returns that kuid.
+ *
+ *      When there is no mapping defined for the user-namespace projid
+ *      pair INVALID_PROJID is returned.  Callers are expected to test
+ *      for and handle handle INVALID_PROJID being returned.  INVALID_PROJID
+ *      may be tested for using projid_valid().
+ */
+kprojid_t make_kprojid(struct user_namespace *ns, projid_t projid)
+{
+        /* Map the uid to a global kernel uid */
+        return KPROJIDT_INIT(map_id_down(&ns->projid_map, projid));
+}
+EXPORT_SYMBOL(make_kprojid);
+
+/**
+ *      from_kprojid - Create a projid from a kprojid user-namespace pair.
+ *      @targ: The user namespace we want a projid in.
+ *      @kprojid: The kernel internal project identifier to start with.
+ *
+ *      Map @kprojid into the user-namespace specified by @targ and
+ *      return the resulting projid.
+ *
+ *      There is always a mapping into the initial user_namespace.
+ *
+ *      If @kprojid has no mapping in @targ (projid_t)-1 is returned.
+ */
+projid_t from_kprojid(struct user_namespace *targ, kprojid_t kprojid)
+{
+        /* Map the uid from a global kernel uid */
+        return map_id_up(&targ->projid_map, __kprojid_val(kprojid));
+}
+EXPORT_SYMBOL(from_kprojid);
+
+/**
+ *      from_kprojid_munged - Create a projiid from a kprojid user-namespace pair.
+ *      @targ: The user namespace we want a projid in.
+ *      @kprojid: The kernel internal projid to start with.
+ *
+ *      Map @kprojid into the user-namespace specified by @targ and
+ *      return the resulting projid.
+ *
+ *      There is always a mapping into the initial user_namespace.
+ *
+ *      Unlike from_kprojid from_kprojid_munged never fails and always
+ *      returns a valid projid.  This makes from_kprojid_munged
+ *      appropriate for use in syscalls like stat and where
+ *      failing the system call and failing to provide a valid projid are
+ *      not an options.
+ *
+ *      If @kprojid has no mapping in @targ OVERFLOW_PROJID is returned.
+ */
+projid_t from_kprojid_munged(struct user_namespace *targ, kprojid_t kprojid)
+{
+        projid_t projid;
+        projid = from_kprojid(targ, kprojid);
+
+        if (projid == (projid_t) -1)
+                projid = OVERFLOW_PROJID;
+        return projid;
+}
+EXPORT_SYMBOL(from_kprojid_munged);
+
+
 static int uid_m_show(struct seq_file *seq, void *v)
 {
         struct user_namespace *ns = seq->private;
@@ -337,6 +407,27 @@ static int gid_m_show(struct seq_file *seq, void *v)
         return 0;
 }
 
+static int projid_m_show(struct seq_file *seq, void *v)
+{
+        struct user_namespace *ns = seq->private;
+        struct uid_gid_extent *extent = v;
+        struct user_namespace *lower_ns;
+        projid_t lower;
+
+        lower_ns = seq_user_ns(seq);
+        if ((lower_ns == ns) && lower_ns->parent)
+                lower_ns = lower_ns->parent;
+
+        lower = from_kprojid(lower_ns, KPROJIDT_INIT(extent->lower_first));
+
+        seq_printf(seq, "%10u %10u %10u\n",
+                extent->first,
+                lower,
+                extent->count);
+
+        return 0;
+}
+
 static void *m_start(struct seq_file *seq, loff_t *ppos, struct uid_gid_map *map)
 {
         struct uid_gid_extent *extent = NULL;
@@ -362,6 +453,13 @@ static void *gid_m_start(struct seq_file *seq, loff_t *ppos)
         return m_start(seq, ppos, &ns->gid_map);
 }
 
+static void *projid_m_start(struct seq_file *seq, loff_t *ppos)
+{
+        struct user_namespace *ns = seq->private;
+
+        return m_start(seq, ppos, &ns->projid_map);
+}
+
 static void *m_next(struct seq_file *seq, void *v, loff_t *pos)
 {
         (*pos)++;
@@ -387,6 +485,13 @@ struct seq_operations proc_gid_seq_operations = {
         .show = gid_m_show,
 };
 
+struct seq_operations proc_projid_seq_operations = {
+        .start = projid_m_start,
+        .stop = m_stop,
+        .next = m_next,
+        .show = projid_m_show,
+};
+
 static DEFINE_MUTEX(id_map_mutex);
 
 static ssize_t map_write(struct file *file, const char __user *buf,
@@ -434,7 +539,7 @@ static ssize_t map_write(struct file *file, const char __user *buf,
         /* Require the appropriate privilege CAP_SETUID or CAP_SETGID
          * over the user namespace in order to set the id mapping.
          */
-        if (!ns_capable(ns, cap_setid))
+        if (cap_valid(cap_setid) && !ns_capable(ns, cap_setid))
                 goto out;
 
         /* Get a buffer */
@@ -584,9 +689,30 @@ ssize_t proc_gid_map_write(struct file *file, const char __user *buf, size_t siz
                          &ns->gid_map, &ns->parent->gid_map);
 }
 
+ssize_t proc_projid_map_write(struct file *file, const char __user *buf, size_t size, loff_t *ppos)
+{
+        struct seq_file *seq = file->private_data;
+        struct user_namespace *ns = seq->private;
+        struct user_namespace *seq_ns = seq_user_ns(seq);
+
+        if (!ns->parent)
+                return -EPERM;
+
+        if ((seq_ns != ns) && (seq_ns != ns->parent))
+                return -EPERM;
+
+        /* Anyone can set any valid project id no capability needed */
+        return map_write(file, buf, size, ppos, -1,
+                         &ns->projid_map, &ns->parent->projid_map);
+}
+
 static bool new_idmap_permitted(struct user_namespace *ns, int cap_setid,
                                 struct uid_gid_map *new_map)
 {
+        /* Allow anyone to set a mapping that doesn't require privilege */
+        if (!cap_valid(cap_setid))
+                return true;
+
         /* Allow the specified ids if we have the appropriate capability
          * (CAP_SETUID or CAP_SETGID) over the parent user namespace.
          */