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
  ...

13 files changed, 166 insertions, 95 deletions

diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h
index c865bfdfe81..37e4a72a7d1 100644
--- a/fs/cifs/cifs_fs_sb.h
+++ b/fs/cifs/cifs_fs_sb.h
@@ -55,10 +55,10 @@ struct cifs_sb_info {
 	unsigned int wsize;
 	unsigned long actimeo; /* attribute cache timeout (jiffies) */
 	atomic_t active;
-	uid_t	mnt_uid;
-	gid_t	mnt_gid;
-	uid_t	mnt_backupuid;
-	gid_t	mnt_backupgid;
+	kuid_t	mnt_uid;
+	kgid_t	mnt_gid;
+	kuid_t	mnt_backupuid;
+	kgid_t	mnt_backupgid;
 	umode_t	mnt_file_mode;
 	umode_t	mnt_dir_mode;
 	unsigned int mnt_cifs_flags;
diff --git a/fs/cifs/cifs_spnego.c b/fs/cifs/cifs_spnego.c
index 086f381d648..10e77476129 100644
--- a/fs/cifs/cifs_spnego.c
+++ b/fs/cifs/cifs_spnego.c
@@ -149,10 +149,12 @@ cifs_get_spnego_key(struct cifs_ses *sesInfo)
 		goto out;
 
 	dp = description + strlen(description);
-	sprintf(dp, ";uid=0x%x", sesInfo->linux_uid);
+	sprintf(dp, ";uid=0x%x",
+		from_kuid_munged(&init_user_ns, sesInfo->linux_uid));
 
 	dp = description + strlen(description);
-	sprintf(dp, ";creduid=0x%x", sesInfo->cred_uid);
+	sprintf(dp, ";creduid=0x%x",
+		from_kuid_munged(&init_user_ns, sesInfo->cred_uid));
 
 	if (sesInfo->user_name) {
 		dp = description + strlen(description);
diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 5cbd00e7406..f1e3f25fe00 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -266,8 +266,8 @@ sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid,
 	struct key *sidkey;
 	char *sidstr;
 	const struct cred *saved_cred;
-	uid_t fuid = cifs_sb->mnt_uid;
-	gid_t fgid = cifs_sb->mnt_gid;
+	kuid_t fuid = cifs_sb->mnt_uid;
+	kgid_t fgid = cifs_sb->mnt_gid;
 
 	/*
 	 * If we have too many subauthorities, then something is really wrong.
@@ -297,6 +297,7 @@ sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid,
 	 * probably a safe assumption but might be better to check based on
 	 * sidtype.
 	 */
+	BUILD_BUG_ON(sizeof(uid_t) != sizeof(gid_t));
 	if (sidkey->datalen != sizeof(uid_t)) {
 		rc = -EIO;
 		cFYI(1, "%s: Downcall contained malformed key "
@@ -305,10 +306,21 @@ sid_to_id(struct cifs_sb_info *cifs_sb, struct cifs_sid *psid,
 		goto out_key_put;
 	}
 
-	if (sidtype == SIDOWNER)
-		memcpy(&fuid, &sidkey->payload.value, sizeof(uid_t));
-	else
-		memcpy(&fgid, &sidkey->payload.value, sizeof(gid_t));
+	if (sidtype == SIDOWNER) {
+		kuid_t uid;
+		uid_t id;
+		memcpy(&id, &sidkey->payload.value, sizeof(uid_t));
+		uid = make_kuid(&init_user_ns, id);
+		if (uid_valid(uid))
+			fuid = uid;
+	} else {
+		kgid_t gid;
+		gid_t id;
+		memcpy(&id, &sidkey->payload.value, sizeof(gid_t));
+		gid = make_kgid(&init_user_ns, id);
+		if (gid_valid(gid))
+			fgid = gid;
+	}
 
 out_key_put:
 	key_put(sidkey);
@@ -346,7 +358,8 @@ init_cifs_idmap(void)
 	if (!cred)
 		return -ENOMEM;
 
-	keyring = keyring_alloc(".cifs_idmap", 0, 0, cred,
+	keyring = keyring_alloc(".cifs_idmap",
+				GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred,
 				(KEY_POS_ALL & ~KEY_POS_SETATTR) |
 				KEY_USR_VIEW | KEY_USR_READ,
 				KEY_ALLOC_NOT_IN_QUOTA, NULL);
@@ -774,7 +787,7 @@ static int parse_sec_desc(struct cifs_sb_info *cifs_sb,
 
 /* Convert permission bits from mode to equivalent CIFS ACL */
 static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
-	__u32 secdesclen, __u64 nmode, uid_t uid, gid_t gid, int *aclflag)
+	__u32 secdesclen, __u64 nmode, kuid_t uid, kgid_t gid, int *aclflag)
 {
 	int rc = 0;
 	__u32 dacloffset;
@@ -806,17 +819,19 @@ static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
 		*aclflag = CIFS_ACL_DACL;
 	} else {
 		memcpy(pnntsd, pntsd, secdesclen);
-		if (uid != NO_CHANGE_32) { /* chown */
+		if (uid_valid(uid)) { /* chown */
+			uid_t id;
 			owner_sid_ptr = (struct cifs_sid *)((char *)pnntsd +
 					le32_to_cpu(pnntsd->osidoffset));
 			nowner_sid_ptr = kmalloc(sizeof(struct cifs_sid),
 								GFP_KERNEL);
 			if (!nowner_sid_ptr)
 				return -ENOMEM;
-			rc = id_to_sid(uid, SIDOWNER, nowner_sid_ptr);
+			id = from_kuid(&init_user_ns, uid);
+			rc = id_to_sid(id, SIDOWNER, nowner_sid_ptr);
 			if (rc) {
 				cFYI(1, "%s: Mapping error %d for owner id %d",
-						__func__, rc, uid);
+						__func__, rc, id);
 				kfree(nowner_sid_ptr);
 				return rc;
 			}
@@ -824,17 +839,19 @@ static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
 			kfree(nowner_sid_ptr);
 			*aclflag = CIFS_ACL_OWNER;
 		}
-		if (gid != NO_CHANGE_32) { /* chgrp */
+		if (gid_valid(gid)) { /* chgrp */
+			gid_t id;
 			group_sid_ptr = (struct cifs_sid *)((char *)pnntsd +
 					le32_to_cpu(pnntsd->gsidoffset));
 			ngroup_sid_ptr = kmalloc(sizeof(struct cifs_sid),
 								GFP_KERNEL);
 			if (!ngroup_sid_ptr)
 				return -ENOMEM;
-			rc = id_to_sid(gid, SIDGROUP, ngroup_sid_ptr);
+			id = from_kgid(&init_user_ns, gid);
+			rc = id_to_sid(id, SIDGROUP, ngroup_sid_ptr);
 			if (rc) {
 				cFYI(1, "%s: Mapping error %d for group id %d",
-						__func__, rc, gid);
+						__func__, rc, id);
 				kfree(ngroup_sid_ptr);
 				return rc;
 			}
@@ -1002,7 +1019,7 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
 /* Convert mode bits to an ACL so we can update the ACL on the server */
 int
 id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode,
-			uid_t uid, gid_t gid)
+			kuid_t uid, kgid_t gid)
 {
 	int rc = 0;
 	int aclflag = CIFS_ACL_DACL; /* default flag to set */
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index de7f9168a11..9be09b21b4e 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -375,13 +375,15 @@ cifs_show_options(struct seq_file *s, struct dentry *root)
 				   (int)(srcaddr->sa_family));
 	}
 
-	seq_printf(s, ",uid=%u", cifs_sb->mnt_uid);
+	seq_printf(s, ",uid=%u",
+		   from_kuid_munged(&init_user_ns, cifs_sb->mnt_uid));
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)
 		seq_printf(s, ",forceuid");
 	else
 		seq_printf(s, ",noforceuid");
 
-	seq_printf(s, ",gid=%u", cifs_sb->mnt_gid);
+	seq_printf(s, ",gid=%u",
+		   from_kgid_munged(&init_user_ns, cifs_sb->mnt_gid));
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)
 		seq_printf(s, ",forcegid");
 	else
@@ -436,9 +438,13 @@ cifs_show_options(struct seq_file *s, struct dentry *root)
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM)
 		seq_printf(s, ",noperm");
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID)
-		seq_printf(s, ",backupuid=%u", cifs_sb->mnt_backupuid);
+		seq_printf(s, ",backupuid=%u",
+			   from_kuid_munged(&init_user_ns,
+					    cifs_sb->mnt_backupuid));
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID)
-		seq_printf(s, ",backupgid=%u", cifs_sb->mnt_backupgid);
+		seq_printf(s, ",backupgid=%u",
+			   from_kgid_munged(&init_user_ns,
+					    cifs_sb->mnt_backupgid));
 
 	seq_printf(s, ",rsize=%u", cifs_sb->rsize);
 	seq_printf(s, ",wsize=%u", cifs_sb->wsize);
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index e6899cea1c3..4f07f6fbe49 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -400,11 +400,11 @@ struct smb_vol {
 	char *iocharset;  /* local code page for mapping to and from Unicode */
 	char source_rfc1001_name[RFC1001_NAME_LEN_WITH_NULL]; /* clnt nb name */
 	char target_rfc1001_name[RFC1001_NAME_LEN_WITH_NULL]; /* srvr nb name */
-	uid_t cred_uid;
-	uid_t linux_uid;
-	gid_t linux_gid;
-	uid_t backupuid;
-	gid_t backupgid;
+	kuid_t cred_uid;
+	kuid_t linux_uid;
+	kgid_t linux_gid;
+	kuid_t backupuid;
+	kgid_t backupgid;
 	umode_t file_mode;
 	umode_t dir_mode;
 	unsigned secFlg;
@@ -703,8 +703,8 @@ struct cifs_ses {
 	char *serverNOS;	/* name of network operating system of server */
 	char *serverDomain;	/* security realm of server */
 	__u64 Suid;		/* remote smb uid  */
-	uid_t linux_uid;        /* overriding owner of files on the mount */
-	uid_t cred_uid;		/* owner of credentials */
+	kuid_t linux_uid;	/* overriding owner of files on the mount */
+	kuid_t cred_uid;	/* owner of credentials */
 	unsigned int capabilities;
 	char serverName[SERVER_NAME_LEN_WITH_NULL * 2];	/* BB make bigger for
 				TCP names - will ipv6 and sctp addresses fit? */
@@ -838,7 +838,7 @@ struct cifs_tcon {
  */
 struct tcon_link {
 	struct rb_node		tl_rbnode;
-	uid_t			tl_uid;
+	kuid_t			tl_uid;
 	unsigned long		tl_flags;
 #define TCON_LINK_MASTER	0
 #define TCON_LINK_PENDING	1
@@ -931,7 +931,7 @@ struct cifsFileInfo {
 	struct list_head tlist;	/* pointer to next fid owned by tcon */
 	struct list_head flist;	/* next fid (file instance) for this inode */
 	struct cifs_fid_locks *llist;	/* brlocks held by this fid */
-	unsigned int uid;	/* allows finding which FileInfo structure */
+	kuid_t uid;		/* allows finding which FileInfo structure */
 	__u32 pid;		/* process id who opened file */
 	struct cifs_fid fid;	/* file id from remote */
 	/* BB add lock scope info here if needed */ ;
@@ -1245,8 +1245,8 @@ struct cifs_fattr {
 	u64		cf_eof;
 	u64		cf_bytes;
 	u64		cf_createtime;
-	uid_t		cf_uid;
-	gid_t		cf_gid;
+	kuid_t		cf_uid;
+	kgid_t		cf_gid;
 	umode_t		cf_mode;
 	dev_t		cf_rdev;
 	unsigned int	cf_nlink;
diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index b9d59a948a2..e996ff6b26d 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -277,7 +277,6 @@
 #define CIFS_NO_HANDLE        0xFFFF
 
 #define NO_CHANGE_64          0xFFFFFFFFFFFFFFFFULL
-#define NO_CHANGE_32          0xFFFFFFFFUL
 
 /* IPC$ in ASCII */
 #define CIFS_IPC_RESOURCE "\x49\x50\x43\x24"
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 1988c1baa22..f450f0683dd 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -46,7 +46,8 @@ extern void _free_xid(unsigned int);
 ({								\
 	unsigned int __xid = _get_xid();				\
 	cFYI(1, "CIFS VFS: in %s as Xid: %u with uid: %d",	\
-	     __func__, __xid, current_fsuid());			\
+	     __func__, __xid,					\
+	     from_kuid(&init_user_ns, current_fsuid()));	\
 	__xid;							\
 })
 
@@ -161,7 +162,7 @@ extern int cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb,
 			      struct cifs_fattr *fattr, struct inode *inode,
 			      const char *path, const __u16 *pfid);
 extern int id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64,
-					uid_t, gid_t);
+					kuid_t, kgid_t);
 extern struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *, struct inode *,
 					const char *, u32 *);
 extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *,
@@ -304,8 +305,8 @@ struct cifs_unix_set_info_args {
 	__u64	atime;
 	__u64	mtime;
 	__u64	mode;
-	__u64	uid;
-	__u64	gid;
+	kuid_t	uid;
+	kgid_t	gid;
 	dev_t	device;
 };
 
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 76d0d299885..00e12f2d626 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -5819,8 +5819,14 @@ static void
 cifs_fill_unix_set_info(FILE_UNIX_BASIC_INFO *data_offset,
 			const struct cifs_unix_set_info_args *args)
 {
+	u64 uid = NO_CHANGE_64, gid = NO_CHANGE_64;
 	u64 mode = args->mode;
 
+	if (uid_valid(args->uid))
+		uid = from_kuid(&init_user_ns, args->uid);
+	if (gid_valid(args->gid))
+		gid = from_kgid(&init_user_ns, args->gid);
+
 	/*
 	 * Samba server ignores set of file size to zero due to bugs in some
 	 * older clients, but we should be precise - we use SetFileSize to
@@ -5833,8 +5839,8 @@ cifs_fill_unix_set_info(FILE_UNIX_BASIC_INFO *data_offset,
 	data_offset->LastStatusChange = cpu_to_le64(args->ctime);
 	data_offset->LastAccessTime = cpu_to_le64(args->atime);
 	data_offset->LastModificationTime = cpu_to_le64(args->mtime);
-	data_offset->Uid = cpu_to_le64(args->uid);
-	data_offset->Gid = cpu_to_le64(args->gid);
+	data_offset->Uid = cpu_to_le64(uid);
+	data_offset->Gid = cpu_to_le64(gid);
 	/* better to leave device as zero when it is  */
 	data_offset->DevMajor = cpu_to_le64(MAJOR(args->device));
 	data_offset->DevMinor = cpu_to_le64(MINOR(args->device));
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 12b3da39733..4474a57f30a 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))
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 8719bbe0dcc..1cd01621744 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -342,14 +342,14 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid,
 
 		*created |= FILE_CREATED;
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
-			args.uid = (__u64) current_fsuid();
+			args.uid = current_fsuid();
 			if (inode->i_mode & S_ISGID)
-				args.gid = (__u64) inode->i_gid;
+				args.gid = inode->i_gid;
 			else
-				args.gid = (__u64) current_fsgid();
+				args.gid = current_fsgid();
 		} else {
-			args.uid = NO_CHANGE_64;
-			args.gid = NO_CHANGE_64;
+			args.uid = INVALID_UID; /* no change */
+			args.gid = INVALID_GID; /* no change */
 		}
 		CIFSSMBUnixSetFileInfo(xid, tcon, &args, fid->netfid,
 				       current->tgid);
@@ -588,11 +588,11 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
 			.device	= device_number,
 		};
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
-			args.uid = (__u64) current_fsuid();
-			args.gid = (__u64) current_fsgid();
+			args.uid = current_fsuid();
+			args.gid = current_fsgid();
 		} else {
-			args.uid = NO_CHANGE_64;
-			args.gid = NO_CHANGE_64;
+			args.uid = INVALID_UID; /* no change */
+			args.gid = INVALID_GID; /* no change */
 		}
 		rc = CIFSSMBUnixSetPathInfo(xid, pTcon, full_path, &args,
 					    cifs_sb->local_nls,
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 8ea6ca50a66..a8d8b589ee0 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -515,8 +515,8 @@ int cifs_open(struct inode *inode, struct file *file)
 		 */
 		struct cifs_unix_set_info_args args = {
 			.mode	= inode->i_mode,
-			.uid	= NO_CHANGE_64,
-			.gid	= NO_CHANGE_64,
+			.uid	= INVALID_UID, /* no change */
+			.gid	= INVALID_GID, /* no change */
 			.ctime	= NO_CHANGE_64,
 			.atime	= NO_CHANGE_64,
 			.mtime	= NO_CHANGE_64,
@@ -1693,7 +1693,7 @@ struct cifsFileInfo *find_readable_file(struct cifsInodeInfo *cifs_inode,
 	   are always at the end of the list but since the first entry might
 	   have a close pending, we go through the whole list */
 	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
-		if (fsuid_only && open_file->uid != current_fsuid())
+		if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
 			continue;
 		if (OPEN_FMODE(open_file->f_flags) & FMODE_READ) {
 			if (!open_file->invalidHandle) {
@@ -1746,7 +1746,7 @@ refind_writable:
 	list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
 		if (!any_available && open_file->pid != current->tgid)
 			continue;
-		if (fsuid_only && open_file->uid != current_fsuid())
+		if (fsuid_only && !uid_eq(open_file->uid, current_fsuid()))
 			continue;
 		if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
 			if (!open_file->invalidHandle) {
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index ed6208ff85a..9638233964f 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -244,15 +244,25 @@ cifs_unix_basic_to_fattr(struct cifs_fattr *fattr, FILE_UNIX_BASIC_INFO *info,
 		break;
 	}
 
-	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)
-		fattr->cf_uid = cifs_sb->mnt_uid;
-	else
-		fattr->cf_uid = le64_to_cpu(info->Uid);
-
-	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)
-		fattr->cf_gid = cifs_sb->mnt_gid;
-	else
-		fattr->cf_gid = le64_to_cpu(info->Gid);
+	fattr->cf_uid = cifs_sb->mnt_uid;
+	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_UID)) {
+		u64 id = le64_to_cpu(info->Uid);
+		if (id < ((uid_t)-1)) {
+			kuid_t uid = make_kuid(&init_user_ns, id);
+			if (uid_valid(uid))
+				fattr->cf_uid = uid;
+		}
+	}
+	
+	fattr->cf_gid = cifs_sb->mnt_gid;
+	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID)) {
+		u64 id = le64_to_cpu(info->Gid);
+		if (id < ((gid_t)-1)) {
+			kgid_t gid = make_kgid(&init_user_ns, id);
+			if (gid_valid(gid))
+				fattr->cf_gid = gid;
+		}
+	}
 
 	fattr->cf_nlink = le64_to_cpu(info->Nlinks);
 }
@@ -1245,14 +1255,14 @@ cifs_mkdir_qinfo(struct inode *parent, struct dentry *dentry, umode_t mode,
 			.device	= 0,
 		};
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
-			args.uid = (__u64)current_fsuid();
+			args.uid = current_fsuid();
 			if (parent->i_mode & S_ISGID)
-				args.gid = (__u64)parent->i_gid;
+				args.gid = parent->i_gid;
 			else
-				args.gid = (__u64)current_fsgid();
+				args.gid = current_fsgid();
 		} else {
-			args.uid = NO_CHANGE_64;
-			args.gid = NO_CHANGE_64;
+			args.uid = INVALID_UID; /* no change */
+			args.gid = INVALID_GID; /* no change */
 		}
 		CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
 				       cifs_sb->local_nls,
@@ -2013,12 +2023,12 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
 	if (attrs->ia_valid & ATTR_UID)
 		args->uid = attrs->ia_uid;
 	else
-		args->uid = NO_CHANGE_64;
+		args->uid = INVALID_UID; /* no change */
 
 	if (attrs->ia_valid & ATTR_GID)
 		args->gid = attrs->ia_gid;
 	else
-		args->gid = NO_CHANGE_64;
+		args->gid = INVALID_GID; /* no change */
 
 	if (attrs->ia_valid & ATTR_ATIME)
 		args->atime = cifs_UnixTimeToNT(attrs->ia_atime);
@@ -2086,8 +2096,8 @@ static int
 cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 {
 	unsigned int xid;
-	uid_t uid = NO_CHANGE_32;
-	gid_t gid = NO_CHANGE_32;
+	kuid_t uid = INVALID_UID;
+	kgid_t gid = INVALID_GID;
 	struct inode *inode = direntry->d_inode;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 	struct cifsInodeInfo *cifsInode = CIFS_I(inode);
@@ -2146,7 +2156,7 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 
 #ifdef CONFIG_CIFS_ACL
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
-		if (uid != NO_CHANGE_32 || gid != NO_CHANGE_32) {
+		if (uid_valid(uid) || gid_valid(gid)) {
 			rc = id_mode_to_cifs_acl(inode, full_path, NO_CHANGE_64,
 							uid, gid);
 			if (rc) {
@@ -2170,7 +2180,7 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 #ifdef CONFIG_CIFS_ACL
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) {
 			rc = id_mode_to_cifs_acl(inode, full_path, mode,
-						NO_CHANGE_32, NO_CHANGE_32);
+						INVALID_UID, INVALID_GID);
 			if (rc) {
 				cFYI(1, "%s: Setting ACL failed with error: %d",
 					__func__, rc);
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 3a00c0d0cea..1b15bf839f3 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -569,7 +569,7 @@ bool
 backup_cred(struct cifs_sb_info *cifs_sb)
 {
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
-		if (cifs_sb->mnt_backupuid == current_fsuid())
+		if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
 			return true;
 	}
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {