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, 48 insertions, 18 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 12b3da3..4474a57 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -987,6 +987,41 @@ static int get_option_ul(substring_t args[], unsigned long *option)
 	return rc;
 }
 
+static int get_option_uid(substring_t args[], kuid_t *result)
+{
+	unsigned long value;
+	kuid_t uid;
+	int rc;
+
+	rc = get_option_ul(args, &value);
+	if (rc)
+		return rc;
+
+	uid = make_kuid(current_user_ns(), value);
+	if (!uid_valid(uid))
+		return -EINVAL;
+
+	*result = uid;
+	return 0;
+}
+
+static int get_option_gid(substring_t args[], kgid_t *result)
+{
+	unsigned long value;
+	kgid_t gid;
+	int rc;
+
+	rc = get_option_ul(args, &value);
+	if (rc)
+		return rc;
+
+	gid = make_kgid(current_user_ns(), value);
+	if (!gid_valid(gid))
+		return -EINVAL;
+
+	*result = gid;
+	return 0;
+}
 
 static int cifs_parse_security_flavors(char *value,
 				       struct smb_vol *vol)
@@ -1424,47 +1459,42 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 
 		/* Numeric Values */
 		case Opt_backupuid:
-			if (get_option_ul(args, &option)) {
+			if (get_option_uid(args, &vol->backupuid)) {
 				cERROR(1, "%s: Invalid backupuid value",
 					__func__);
 				goto cifs_parse_mount_err;
 			}
-			vol->backupuid = option;
 			vol->backupuid_specified = true;
 			break;
 		case Opt_backupgid:
-			if (get_option_ul(args, &option)) {
+			if (get_option_gid(args, &vol->backupgid)) {
 				cERROR(1, "%s: Invalid backupgid value",
 					__func__);
 				goto cifs_parse_mount_err;
 			}
-			vol->backupgid = option;
 			vol->backupgid_specified = true;
 			break;
 		case Opt_uid:
-			if (get_option_ul(args, &option)) {
+			if (get_option_uid(args, &vol->linux_uid)) {
 				cERROR(1, "%s: Invalid uid value",
 					__func__);
 				goto cifs_parse_mount_err;
 			}
-			vol->linux_uid = option;
 			uid_specified = true;
 			break;
 		case Opt_cruid:
-			if (get_option_ul(args, &option)) {
+			if (get_option_uid(args, &vol->cred_uid)) {
 				cERROR(1, "%s: Invalid cruid value",
 					__func__);
 				goto cifs_parse_mount_err;
 			}
-			vol->cred_uid = option;
 			break;
 		case Opt_gid:
-			if (get_option_ul(args, &option)) {
+			if (get_option_gid(args, &vol->linux_gid)) {
 				cERROR(1, "%s: Invalid gid value",
 						__func__);
 				goto cifs_parse_mount_err;
 			}
-			vol->linux_gid = option;
 			gid_specified = true;
 			break;
 		case Opt_file_mode:
@@ -2241,7 +2271,7 @@ static int match_session(struct cifs_ses *ses, struct smb_vol *vol)
 {
 	switch (ses->server->secType) {
 	case Kerberos:
-		if (vol->cred_uid != ses->cred_uid)
+		if (!uid_eq(vol->cred_uid, ses->cred_uid))
 			return 0;
 		break;
 	default:
@@ -2713,7 +2743,7 @@ compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
 	if (new->rsize && new->rsize < old->rsize)
 		return 0;
 
-	if (old->mnt_uid != new->mnt_uid || old->mnt_gid != new->mnt_gid)
+	if (!uid_eq(old->mnt_uid, new->mnt_uid) || !gid_eq(old->mnt_gid, new->mnt_gid))
 		return 0;
 
 	if (old->mnt_file_mode != new->mnt_file_mode ||
@@ -3919,7 +3949,7 @@ cifs_set_vol_auth(struct smb_vol *vol, struct cifs_ses *ses)
 }
 
 static struct cifs_tcon *
-cifs_construct_tcon(struct cifs_sb_info *cifs_sb, uid_t fsuid)
+cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
 {
 	int rc;
 	struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
@@ -3989,7 +4019,7 @@ cifs_sb_tcon_pending_wait(void *unused)
 
 /* find and return a tlink with given uid */
 static struct tcon_link *
-tlink_rb_search(struct rb_root *root, uid_t uid)
+tlink_rb_search(struct rb_root *root, kuid_t uid)
 {
 	struct rb_node *node = root->rb_node;
 	struct tcon_link *tlink;
@@ -3997,9 +4027,9 @@ tlink_rb_search(struct rb_root *root, uid_t uid)
 	while (node) {
 		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
 
-		if (tlink->tl_uid > uid)
+		if (uid_gt(tlink->tl_uid, uid))
 			node = node->rb_left;
-		else if (tlink->tl_uid < uid)
+		else if (uid_lt(tlink->tl_uid, uid))
 			node = node->rb_right;
 		else
 			return tlink;
@@ -4018,7 +4048,7 @@ tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
 		tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
 		parent = *new;
 
-		if (tlink->tl_uid > new_tlink->tl_uid)
+		if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
 			new = &((*new)->rb_left);
 		else
 			new = &((*new)->rb_right);
@@ -4048,7 +4078,7 @@ struct tcon_link *
 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
 {
 	int ret;
-	uid_t fsuid = current_fsuid();
+	kuid_t fsuid = current_fsuid();
 	struct tcon_link *tlink, *newtlink;
 
 	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))