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, 32 insertions, 15 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 5cbd00e74067..f1e3f25fe004 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 */