diff --git a/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c b/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c
index 20ce5b580b8..3f8284bf2b5 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c
@@ -12908,7 +12908,8 @@ dtrace_dof_copyin(uintptr_t uarg, int *errp)
 
 	dof = kmem_alloc(hdr.dofh_loadsz, KM_SLEEP);
 
-	if (copyin((void *)uarg, dof, hdr.dofh_loadsz) != 0) {
+	if (copyin((void *)uarg, dof, hdr.dofh_loadsz) != 0 ||
+	    dof->dofh_loadsz != hdr.dofh_loadsz) {
 		kmem_free(dof, hdr.dofh_loadsz);
 		*errp = EFAULT;
 		return (NULL);
diff --git a/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c b/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c
index 895b871b019..efb470b0d1d 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/dtrace/fasttrap.c
@@ -2277,7 +2277,8 @@ fasttrap_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int fflag,
 
 		probe = kmem_alloc(size, KM_SLEEP);
 
-		if (copyin(uprobe, probe, size) != 0) {
+		if (copyin(uprobe, probe, size) != 0 ||
+		    probe->ftps_noffs != noffs) {
 			kmem_free(probe, size);
 			return (EFAULT);
 		}