diff --git a/kernel/sys.c b/kernel/sys.c
index 3996281..aff09f2 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -555,9 +555,19 @@
  */
 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
 {
+	struct user_namespace *ns = current_user_ns();
 	const struct cred *old;
 	struct cred *new;
 	int retval;
+	kgid_t krgid, kegid;
+
+	krgid = make_kgid(ns, rgid);
+	kegid = make_kgid(ns, egid);
+
+	if ((rgid != (gid_t) -1) && !gid_valid(krgid))
+		return -EINVAL;
+	if ((egid != (gid_t) -1) && !gid_valid(kegid))
+		return -EINVAL;
 
 	new = prepare_creds();
 	if (!new)
@@ -566,25 +576,25 @@
 
 	retval = -EPERM;
 	if (rgid != (gid_t) -1) {
-		if (old->gid == rgid ||
-		    old->egid == rgid ||
+		if (gid_eq(old->gid, krgid) ||
+		    gid_eq(old->egid, krgid) ||
 		    nsown_capable(CAP_SETGID))
-			new->gid = rgid;
+			new->gid = krgid;
 		else
 			goto error;
 	}
 	if (egid != (gid_t) -1) {
-		if (old->gid == egid ||
-		    old->egid == egid ||
-		    old->sgid == egid ||
+		if (gid_eq(old->gid, kegid) ||
+		    gid_eq(old->egid, kegid) ||
+		    gid_eq(old->sgid, kegid) ||
 		    nsown_capable(CAP_SETGID))
-			new->egid = egid;
+			new->egid = kegid;
 		else
 			goto error;
 	}
 
 	if (rgid != (gid_t) -1 ||
-	    (egid != (gid_t) -1 && egid != old->gid))
+	    (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
 		new->sgid = new->egid;
 	new->fsgid = new->egid;
 
@@ -602,9 +612,15 @@
  */
 SYSCALL_DEFINE1(setgid, gid_t, gid)
 {
+	struct user_namespace *ns = current_user_ns();
 	const struct cred *old;
 	struct cred *new;
 	int retval;
+	kgid_t kgid;
+
+	kgid = make_kgid(ns, gid);
+	if (!gid_valid(kgid))
+		return -EINVAL;
 
 	new = prepare_creds();
 	if (!new)
@@ -613,9 +629,9 @@
 
 	retval = -EPERM;
 	if (nsown_capable(CAP_SETGID))
-		new->gid = new->egid = new->sgid = new->fsgid = gid;
-	else if (gid == old->gid || gid == old->sgid)
-		new->egid = new->fsgid = gid;
+		new->gid = new->egid = new->sgid = new->fsgid = kgid;
+	else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
+		new->egid = new->fsgid = kgid;
 	else
 		goto error;
 
@@ -672,9 +688,19 @@
  */
 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
 {
+	struct user_namespace *ns = current_user_ns();
 	const struct cred *old;
 	struct cred *new;
 	int retval;
+	kuid_t kruid, keuid;
+
+	kruid = make_kuid(ns, ruid);
+	keuid = make_kuid(ns, euid);
+
+	if ((ruid != (uid_t) -1) && !uid_valid(kruid))
+		return -EINVAL;
+	if ((euid != (uid_t) -1) && !uid_valid(keuid))
+		return -EINVAL;
 
 	new = prepare_creds();
 	if (!new)
@@ -683,29 +709,29 @@
 
 	retval = -EPERM;
 	if (ruid != (uid_t) -1) {
-		new->uid = ruid;
-		if (old->uid != ruid &&
-		    old->euid != ruid &&
+		new->uid = kruid;
+		if (!uid_eq(old->uid, kruid) &&
+		    !uid_eq(old->euid, kruid) &&
 		    !nsown_capable(CAP_SETUID))
 			goto error;
 	}
 
 	if (euid != (uid_t) -1) {
-		new->euid = euid;
-		if (old->uid != euid &&
-		    old->euid != euid &&
-		    old->suid != euid &&
+		new->euid = keuid;
+		if (!uid_eq(old->uid, keuid) &&
+		    !uid_eq(old->euid, keuid) &&
+		    !uid_eq(old->suid, keuid) &&
 		    !nsown_capable(CAP_SETUID))
 			goto error;
 	}
 
-	if (new->uid != old->uid) {
+	if (!uid_eq(new->uid, old->uid)) {
 		retval = set_user(new);
 		if (retval < 0)
 			goto error;
 	}
 	if (ruid != (uid_t) -1 ||
-	    (euid != (uid_t) -1 && euid != old->uid))
+	    (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
 		new->suid = new->euid;
 	new->fsuid = new->euid;
 
@@ -733,9 +759,15 @@
  */
 SYSCALL_DEFINE1(setuid, uid_t, uid)
 {
+	struct user_namespace *ns = current_user_ns();
 	const struct cred *old;
 	struct cred *new;
 	int retval;
+	kuid_t kuid;
+
+	kuid = make_kuid(ns, uid);
+	if (!uid_valid(kuid))
+		return -EINVAL;
 
 	new = prepare_creds();
 	if (!new)
@@ -744,17 +776,17 @@
 
 	retval = -EPERM;
 	if (nsown_capable(CAP_SETUID)) {
-		new->suid = new->uid = uid;
-		if (uid != old->uid) {
+		new->suid = new->uid = kuid;
+		if (!uid_eq(kuid, old->uid)) {
 			retval = set_user(new);
 			if (retval < 0)
 				goto error;
 		}
-	} else if (uid != old->uid && uid != new->suid) {
+	} else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
 		goto error;
 	}
 
-	new->fsuid = new->euid = uid;
+	new->fsuid = new->euid = kuid;
 
 	retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
 	if (retval < 0)
@@ -774,9 +806,24 @@
  */
 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
 {
+	struct user_namespace *ns = current_user_ns();
 	const struct cred *old;
 	struct cred *new;
 	int retval;
+	kuid_t kruid, keuid, ksuid;
+
+	kruid = make_kuid(ns, ruid);
+	keuid = make_kuid(ns, euid);
+	ksuid = make_kuid(ns, suid);
+
+	if ((ruid != (uid_t) -1) && !uid_valid(kruid))
+		return -EINVAL;
+
+	if ((euid != (uid_t) -1) && !uid_valid(keuid))
+		return -EINVAL;
+
+	if ((suid != (uid_t) -1) && !uid_valid(ksuid))
+		return -EINVAL;
 
 	new = prepare_creds();
 	if (!new)
@@ -786,29 +833,29 @@
 
 	retval = -EPERM;
 	if (!nsown_capable(CAP_SETUID)) {
-		if (ruid != (uid_t) -1 && ruid != old->uid &&
-		    ruid != old->euid  && ruid != old->suid)
+		if (ruid != (uid_t) -1        && !uid_eq(kruid, old->uid) &&
+		    !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
 			goto error;
-		if (euid != (uid_t) -1 && euid != old->uid &&
-		    euid != old->euid  && euid != old->suid)
+		if (euid != (uid_t) -1        && !uid_eq(keuid, old->uid) &&
+		    !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
 			goto error;
-		if (suid != (uid_t) -1 && suid != old->uid &&
-		    suid != old->euid  && suid != old->suid)
+		if (suid != (uid_t) -1        && !uid_eq(ksuid, old->uid) &&
+		    !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
 			goto error;
 	}
 
 	if (ruid != (uid_t) -1) {
-		new->uid = ruid;
-		if (ruid != old->uid) {
+		new->uid = kruid;
+		if (!uid_eq(kruid, old->uid)) {
 			retval = set_user(new);
 			if (retval < 0)
 				goto error;
 		}
 	}
 	if (euid != (uid_t) -1)
-		new->euid = euid;
+		new->euid = keuid;
 	if (suid != (uid_t) -1)
-		new->suid = suid;
+		new->suid = ksuid;
 	new->fsuid = new->euid;
 
 	retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
@@ -822,14 +869,19 @@
 	return retval;
 }
 
-SYSCALL_DEFINE3(getresuid, uid_t __user *, ruid, uid_t __user *, euid, uid_t __user *, suid)
+SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
 {
 	const struct cred *cred = current_cred();
 	int retval;
+	uid_t ruid, euid, suid;
 
-	if (!(retval   = put_user(cred->uid,  ruid)) &&
-	    !(retval   = put_user(cred->euid, euid)))
-		retval = put_user(cred->suid, suid);
+	ruid = from_kuid_munged(cred->user_ns, cred->uid);
+	euid = from_kuid_munged(cred->user_ns, cred->euid);
+	suid = from_kuid_munged(cred->user_ns, cred->suid);
+
+	if (!(retval   = put_user(ruid, ruidp)) &&
+	    !(retval   = put_user(euid, euidp)))
+		retval = put_user(suid, suidp);
 
 	return retval;
 }
@@ -839,9 +891,22 @@
  */
 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
 {
+	struct user_namespace *ns = current_user_ns();
 	const struct cred *old;
 	struct cred *new;
 	int retval;
+	kgid_t krgid, kegid, ksgid;
+
+	krgid = make_kgid(ns, rgid);
+	kegid = make_kgid(ns, egid);
+	ksgid = make_kgid(ns, sgid);
+
+	if ((rgid != (gid_t) -1) && !gid_valid(krgid))
+		return -EINVAL;
+	if ((egid != (gid_t) -1) && !gid_valid(kegid))
+		return -EINVAL;
+	if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
+		return -EINVAL;
 
 	new = prepare_creds();
 	if (!new)
@@ -850,23 +915,23 @@
 
 	retval = -EPERM;
 	if (!nsown_capable(CAP_SETGID)) {
-		if (rgid != (gid_t) -1 && rgid != old->gid &&
-		    rgid != old->egid  && rgid != old->sgid)
+		if (rgid != (gid_t) -1        && !gid_eq(krgid, old->gid) &&
+		    !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
 			goto error;
-		if (egid != (gid_t) -1 && egid != old->gid &&
-		    egid != old->egid  && egid != old->sgid)
+		if (egid != (gid_t) -1        && !gid_eq(kegid, old->gid) &&
+		    !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
 			goto error;
-		if (sgid != (gid_t) -1 && sgid != old->gid &&
-		    sgid != old->egid  && sgid != old->sgid)
+		if (sgid != (gid_t) -1        && !gid_eq(ksgid, old->gid) &&
+		    !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
 			goto error;
 	}
 
 	if (rgid != (gid_t) -1)
-		new->gid = rgid;
+		new->gid = krgid;
 	if (egid != (gid_t) -1)
-		new->egid = egid;
+		new->egid = kegid;
 	if (sgid != (gid_t) -1)
-		new->sgid = sgid;
+		new->sgid = ksgid;
 	new->fsgid = new->egid;
 
 	return commit_creds(new);
@@ -876,14 +941,19 @@
 	return retval;
 }
 
-SYSCALL_DEFINE3(getresgid, gid_t __user *, rgid, gid_t __user *, egid, gid_t __user *, sgid)
+SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
 {
 	const struct cred *cred = current_cred();
 	int retval;
+	gid_t rgid, egid, sgid;
 
-	if (!(retval   = put_user(cred->gid,  rgid)) &&
-	    !(retval   = put_user(cred->egid, egid)))
-		retval = put_user(cred->sgid, sgid);
+	rgid = from_kgid_munged(cred->user_ns, cred->gid);
+	egid = from_kgid_munged(cred->user_ns, cred->egid);
+	sgid = from_kgid_munged(cred->user_ns, cred->sgid);
+
+	if (!(retval   = put_user(rgid, rgidp)) &&
+	    !(retval   = put_user(egid, egidp)))
+		retval = put_user(sgid, sgidp);
 
 	return retval;
 }
@@ -900,18 +970,24 @@
 	const struct cred *old;
 	struct cred *new;
 	uid_t old_fsuid;
+	kuid_t kuid;
+
+	old = current_cred();
+	old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
+
+	kuid = make_kuid(old->user_ns, uid);
+	if (!uid_valid(kuid))
+		return old_fsuid;
 
 	new = prepare_creds();
 	if (!new)
-		return current_fsuid();
-	old = current_cred();
-	old_fsuid = old->fsuid;
+		return old_fsuid;
 
-	if (uid == old->uid  || uid == old->euid  ||
-	    uid == old->suid || uid == old->fsuid ||
+	if (uid_eq(kuid, old->uid)  || uid_eq(kuid, old->euid)  ||
+	    uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
 	    nsown_capable(CAP_SETUID)) {
-		if (uid != old_fsuid) {
-			new->fsuid = uid;
+		if (!uid_eq(kuid, old->fsuid)) {
+			new->fsuid = kuid;
 			if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
 				goto change_okay;
 		}
@@ -933,18 +1009,24 @@
 	const struct cred *old;
 	struct cred *new;
 	gid_t old_fsgid;
+	kgid_t kgid;
+
+	old = current_cred();
+	old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
+
+	kgid = make_kgid(old->user_ns, gid);
+	if (!gid_valid(kgid))
+		return old_fsgid;
 
 	new = prepare_creds();
 	if (!new)
-		return current_fsgid();
-	old = current_cred();
-	old_fsgid = old->fsgid;
+		return old_fsgid;
 
-	if (gid == old->gid  || gid == old->egid  ||
-	    gid == old->sgid || gid == old->fsgid ||
+	if (gid_eq(kgid, old->gid)  || gid_eq(kgid, old->egid)  ||
+	    gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
 	    nsown_capable(CAP_SETGID)) {
-		if (gid != old_fsgid) {
-			new->fsgid = gid;
+		if (!gid_eq(kgid, old->fsgid)) {
+			new->fsgid = kgid;
 			goto change_okay;
 		}
 	}
@@ -1503,10 +1585,10 @@
 	if (cred->user_ns == tcred->user_ns &&
 	    (cred->uid == tcred->euid &&
 	     cred->uid == tcred->suid &&
-	     cred->uid == tcred->uid  &&
+	     cred->uid == tcred->uid &&
 	     cred->gid == tcred->egid &&
 	     cred->gid == tcred->sgid &&
-	     cred->gid == tcred->gid))
+		    cred->gid == tcred->gid))
 		return 0;
 	if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
 		return 0;