Index: sys/kern/kern_prot.c
===================================================================
--- sys/kern/kern_prot.c	(revision 240919)
+++ sys/kern/kern_prot.c	(working copy)
@@ -279,7 +279,7 @@
 
 #ifndef _SYS_SYSPROTO_H_
 struct getgroups_args {
-	u_int	gidsetsize;
+	int	gidsetsize;
 	gid_t	*gidset;
 };
 #endif
@@ -801,7 +801,7 @@
 
 #ifndef _SYS_SYSPROTO_H_
 struct setgroups_args {
-	u_int	gidsetsize;
+	int	gidsetsize;
 	gid_t	*gidset;
 };
 #endif
@@ -812,7 +812,7 @@
 	gid_t *groups = NULL;
 	int error;
 
-	if (uap->gidsetsize > ngroups_max + 1)
+	if (uap->gidsetsize < 0 || uap->gidsetsize > ngroups_max + 1)
 		return (EINVAL);
 	groups = malloc(uap->gidsetsize * sizeof(gid_t), M_TEMP, M_WAITOK);
 	error = copyin(uap->gidset, groups, uap->gidsetsize * sizeof(gid_t));
Index: sys/kern/systrace_args.c
===================================================================
--- sys/kern/systrace_args.c	(revision 240919)
+++ sys/kern/systrace_args.c	(working copy)
@@ -491,7 +491,7 @@
 	/* getgroups */
 	case 79: {
 		struct getgroups_args *p = params;
-		uarg[0] = p->gidsetsize; /* u_int */
+		iarg[0] = p->gidsetsize; /* int */
 		uarg[1] = (intptr_t) p->gidset; /* gid_t * */
 		*n_args = 2;
 		break;
@@ -499,7 +499,7 @@
 	/* setgroups */
 	case 80: {
 		struct setgroups_args *p = params;
-		uarg[0] = p->gidsetsize; /* u_int */
+		iarg[0] = p->gidsetsize; /* int */
 		uarg[1] = (intptr_t) p->gidset; /* gid_t * */
 		*n_args = 2;
 		break;
Index: sys/kern/syscalls.master
===================================================================
--- sys/kern/syscalls.master	(revision 240919)
+++ sys/kern/syscalls.master	(working copy)
@@ -183,9 +183,9 @@
 77	AUE_NULL	OBSOL	vlimit
 78	AUE_MINCORE	STD	{ int mincore(const void *addr, size_t len, \
 				    char *vec); }
-79	AUE_GETGROUPS	STD	{ int getgroups(u_int gidsetsize, \
+79	AUE_GETGROUPS	STD	{ int getgroups(int gidsetsize, \
 				    gid_t *gidset); }
-80	AUE_SETGROUPS	STD	{ int setgroups(u_int gidsetsize, \
+80	AUE_SETGROUPS	STD	{ int setgroups(int gidsetsize, \
 				    gid_t *gidset); }
 81	AUE_GETPGRP	STD	{ int getpgrp(void); }
 82	AUE_SETPGRP	STD	{ int setpgid(int pid, int pgid); }
Index: sys/compat/freebsd32/syscalls.master
===================================================================
--- sys/compat/freebsd32/syscalls.master	(revision 240919)
+++ sys/compat/freebsd32/syscalls.master	(working copy)
@@ -181,9 +181,9 @@
 77	AUE_NULL	OBSOL	vlimit
 78	AUE_MINCORE	NOPROTO	{ int mincore(const void *addr, size_t len, \
 				    char *vec); }
-79	AUE_GETGROUPS	NOPROTO	{ int getgroups(u_int gidsetsize, \
+79	AUE_GETGROUPS	NOPROTO	{ int getgroups(int gidsetsize, \
 				    gid_t *gidset); }
-80	AUE_SETGROUPS	NOPROTO	{ int setgroups(u_int gidsetsize, \
+80	AUE_SETGROUPS	NOPROTO	{ int setgroups(int gidsetsize, \
 				    gid_t *gidset); }
 81	AUE_GETPGRP	NOPROTO	{ int getpgrp(void); }
 82	AUE_SETPGRP	NOPROTO	{ int setpgid(int pid, int pgid); }