diff --git a/arch/arm/src/c5471/c5471_watchdog.c b/arch/arm/src/c5471/c5471_watchdog.c
index e2ffd59d87f16..465eda30c00ad 100644
--- a/arch/arm/src/c5471/c5471_watchdog.c
+++ b/arch/arm/src/c5471/c5471_watchdog.c
@@ -359,7 +359,7 @@ int arm_wdtinit(void)
 
   /* Register as /dev/wdt */
 
-  ret = register_driver("/dev/wdt", &g_wdtops, 0666, NULL);
+  ret = register_driver("/dev/wdt", &g_wdtops, 0600, NULL);
   if (ret)
     {
       return ERROR;
diff --git a/arch/arm/src/common/stm32/stm32_bbsram_m3m4_v1.c b/arch/arm/src/common/stm32/stm32_bbsram_m3m4_v1.c
index 14c132dc8ea45..1d05478796d57 100644
--- a/arch/arm/src/common/stm32/stm32_bbsram_m3m4_v1.c
+++ b/arch/arm/src/common/stm32/stm32_bbsram_m3m4_v1.c
@@ -757,7 +757,7 @@ int stm32_bbsraminitialize(char *devpath, int *sizes)
     {
       snprintf(devname, sizeof(devname), "%s%d", devpath, i);
       ret = register_driver(devname, &g_stm32_bbsram_fops,
-                            0666, &g_bbsram[i]);
+                            0600, &g_bbsram[i]);
     }
 
   /* Disallow Access */
diff --git a/arch/arm/src/common/stm32/stm32_hrtim_m3m4_v1.c b/arch/arm/src/common/stm32/stm32_hrtim_m3m4_v1.c
index 73791c4c21fc8..259b824ff05db 100644
--- a/arch/arm/src/common/stm32/stm32_hrtim_m3m4_v1.c
+++ b/arch/arm/src/common/stm32/stm32_hrtim_m3m4_v1.c
@@ -6037,7 +6037,7 @@ int hrtim_register(const char *path, struct hrtim_dev_s *dev)
 
   /* Register the HRTIM character driver */
 
-  return register_driver(path, &g_hrtim_fops, 0444, dev);
+  return register_driver(path, &g_hrtim_fops, 0440, dev);
 }
 #endif /* CONFIG_STM32_HRTIM_DISABLE_CHARDRV */
 
diff --git a/arch/arm/src/cxd56xx/cxd56_adc.c b/arch/arm/src/cxd56xx/cxd56_adc.c
index 484d44175f2d0..4511149a1d88f 100644
--- a/arch/arm/src/cxd56xx/cxd56_adc.c
+++ b/arch/arm/src/cxd56xx/cxd56_adc.c
@@ -1105,7 +1105,7 @@ int cxd56_adcinitialize(void)
   int ret = OK;
 
 #if defined (CONFIG_CXD56_LPADC0) || defined (CONFIG_CXD56_LPADC0_1) || defined (CONFIG_CXD56_LPADC_ALL)
-  ret = register_driver("/dev/lpadc0", &g_adcops, 0666, &g_lpadc0priv);
+  ret = register_driver("/dev/lpadc0", &g_adcops, 0600, &g_lpadc0priv);
   if (ret < 0)
     {
       aerr("Failed to register driver(lpadc0): %d\n", ret);
@@ -1114,7 +1114,7 @@ int cxd56_adcinitialize(void)
 #endif
 
 #if defined (CONFIG_CXD56_LPADC1) || defined (CONFIG_CXD56_LPADC0_1) || defined (CONFIG_CXD56_LPADC_ALL)
-  ret = register_driver("/dev/lpadc1", &g_adcops, 0666, &g_lpadc1priv);
+  ret = register_driver("/dev/lpadc1", &g_adcops, 0600, &g_lpadc1priv);
   if (ret < 0)
     {
       aerr("Failed to register driver(lpadc1): %d\n", ret);
@@ -1123,7 +1123,7 @@ int cxd56_adcinitialize(void)
 #endif
 
 #if defined (CONFIG_CXD56_LPADC2) || defined (CONFIG_CXD56_LPADC_ALL)
-  ret = register_driver("/dev/lpadc2", &g_adcops, 0666, &g_lpadc2priv);
+  ret = register_driver("/dev/lpadc2", &g_adcops, 0600, &g_lpadc2priv);
   if (ret < 0)
     {
       aerr("Failed to register driver(lpadc2): %d\n", ret);
@@ -1132,7 +1132,7 @@ int cxd56_adcinitialize(void)
 #endif
 
 #if defined (CONFIG_CXD56_LPADC3) || defined (CONFIG_CXD56_LPADC_ALL)
-  ret = register_driver("/dev/lpadc3", &g_adcops, 0666, &g_lpadc3priv);
+  ret = register_driver("/dev/lpadc3", &g_adcops, 0600, &g_lpadc3priv);
   if (ret < 0)
     {
       aerr("Failed to register driver(lpadc3): %d\n", ret);
@@ -1141,7 +1141,7 @@ int cxd56_adcinitialize(void)
 #endif
 
 #ifdef CONFIG_CXD56_HPADC0
-  ret = register_driver("/dev/hpadc0", &g_adcops, 0666, &g_hpadc0priv);
+  ret = register_driver("/dev/hpadc0", &g_adcops, 0600, &g_hpadc0priv);
   if (ret < 0)
     {
       aerr("Failed to register driver(hpadc0): %d\n", ret);
@@ -1150,7 +1150,7 @@ int cxd56_adcinitialize(void)
 #endif
 
 #ifdef CONFIG_CXD56_HPADC1
-  ret = register_driver("/dev/hpadc1", &g_adcops, 0666, &g_hpadc1priv);
+  ret = register_driver("/dev/hpadc1", &g_adcops, 0600, &g_hpadc1priv);
   if (ret < 0)
     {
       aerr("Failed to register driver(hpadc1): %d\n", ret);
diff --git a/arch/arm/src/cxd56xx/cxd56_charger.c b/arch/arm/src/cxd56xx/cxd56_charger.c
index b52b19ffc2891..6db96ea12cc31 100644
--- a/arch/arm/src/cxd56xx/cxd56_charger.c
+++ b/arch/arm/src/cxd56xx/cxd56_charger.c
@@ -623,7 +623,7 @@ int cxd56_charger_initialize(const char *devpath)
 
   /* Register battery driver */
 
-  ret = register_driver(devpath, &g_chargerops, 0666, priv);
+  ret = register_driver(devpath, &g_chargerops, 0600, priv);
   if (ret < 0)
     {
       baterr("ERROR: register_driver failed: %d\n", ret);
diff --git a/arch/arm/src/cxd56xx/cxd56_gauge.c b/arch/arm/src/cxd56xx/cxd56_gauge.c
index 851be2d63f6c5..c3707869640fa 100644
--- a/arch/arm/src/cxd56xx/cxd56_gauge.c
+++ b/arch/arm/src/cxd56xx/cxd56_gauge.c
@@ -347,7 +347,7 @@ int cxd56_gauge_initialize(const char *devpath)
 
   /* Register battery driver */
 
-  ret = register_driver(devpath, &g_gaugeops, 0666, priv);
+  ret = register_driver(devpath, &g_gaugeops, 0600, priv);
   if (ret < 0)
     {
       baterr("ERROR: register_driver failed: %d\n", ret);
diff --git a/arch/arm/src/cxd56xx/cxd56_ge2d.c b/arch/arm/src/cxd56xx/cxd56_ge2d.c
index d907efe2dc109..a60d2ff782286 100644
--- a/arch/arm/src/cxd56xx/cxd56_ge2d.c
+++ b/arch/arm/src/cxd56xx/cxd56_ge2d.c
@@ -186,7 +186,7 @@ int cxd56_ge2dinitialize(const char *devname)
 {
   int ret;
 
-  ret = register_driver(devname, &g_ge2dfops, 0666, NULL);
+  ret = register_driver(devname, &g_ge2dfops, 0600, NULL);
   if (ret != 0)
     {
       return ERROR;
diff --git a/arch/arm/src/cxd56xx/cxd56_geofence.c b/arch/arm/src/cxd56xx/cxd56_geofence.c
index 75b7f104eb9aa..dc4bae07a8998 100644
--- a/arch/arm/src/cxd56xx/cxd56_geofence.c
+++ b/arch/arm/src/cxd56xx/cxd56_geofence.c
@@ -649,7 +649,7 @@ static int cxd56_geofence_register(const char *devpath)
       goto err0;
     }
 
-  ret = register_driver(devpath, &g_geofencefops, 0666, priv);
+  ret = register_driver(devpath, &g_geofencefops, 0600, priv);
   if (ret < 0)
     {
       gnsserr("Failed to register driver: %d\n", ret);
diff --git a/arch/arm/src/cxd56xx/cxd56_gnss.c b/arch/arm/src/cxd56xx/cxd56_gnss.c
index 6f44853bb4d2b..2fd34dc2e7770 100644
--- a/arch/arm/src/cxd56xx/cxd56_gnss.c
+++ b/arch/arm/src/cxd56xx/cxd56_gnss.c
@@ -3207,7 +3207,7 @@ static int cxd56_gnss_register(const char *devpath)
       goto err0;
     }
 
-  ret = register_driver(devpath, &g_gnssfops, 0666, priv);
+  ret = register_driver(devpath, &g_gnssfops, 0600, priv);
   if (ret < 0)
     {
       gnsserr("Failed to register driver: %d\n", ret);
diff --git a/arch/arm/src/cxd56xx/cxd56_hostif.c b/arch/arm/src/cxd56xx/cxd56_hostif.c
index 4ecbfbf9e3928..d8e652a603d68 100644
--- a/arch/arm/src/cxd56xx/cxd56_hostif.c
+++ b/arch/arm/src/cxd56xx/cxd56_hostif.c
@@ -416,7 +416,7 @@ static int hif_initialize(struct hostif_buff_s *buffer)
       snprintf(devpath, sizeof(devpath), "/dev/hostif%c%d",
                (priv->flags & HOSTIF_BUFF_ATTR_READ) ? 'r' : 'w', num);
 
-      ret = register_driver(devpath, &g_hif_fops, 0666, priv);
+      ret = register_driver(devpath, &g_hif_fops, 0600, priv);
       if (ret < 0)
         {
           hiferr("ERROR: Failed to register %s (%d)\n", devpath, ret);
diff --git a/arch/arm/src/cxd56xx/cxd56_sph.c b/arch/arm/src/cxd56xx/cxd56_sph.c
index 42ab58576321f..5f9d68e33cb7d 100644
--- a/arch/arm/src/cxd56xx/cxd56_sph.c
+++ b/arch/arm/src/cxd56xx/cxd56_sph.c
@@ -226,7 +226,7 @@ static inline int cxd56_sphdevinit(const char *devname, int num)
 
   snprintf(fullpath, sizeof(fullpath), "/dev/%s%d", devname, num);
 
-  ret = register_driver(fullpath, &g_sph_fops, 0666, (void *)priv);
+  ret = register_driver(fullpath, &g_sph_fops, 0600, (void *)priv);
   if (ret != 0)
     {
       return ERROR;
diff --git a/arch/arm/src/cxd56xx/cxd56_sysctl.c b/arch/arm/src/cxd56xx/cxd56_sysctl.c
index 10d7ae59007da..dff954cdbaece 100644
--- a/arch/arm/src/cxd56xx/cxd56_sysctl.c
+++ b/arch/arm/src/cxd56xx/cxd56_sysctl.c
@@ -162,5 +162,5 @@ void cxd56_sysctlinitialize(void)
 {
   cxd56_iccinit(CXD56_PROTO_SYSCTL);
   cxd56_iccregisterhandler(CXD56_PROTO_SYSCTL, sysctl_rxhandler, NULL);
-  register_driver("/dev/sysctl", &g_sysctlfops, 0666, NULL);
+  register_driver("/dev/sysctl", &g_sysctlfops, 0600, NULL);
 }
diff --git a/arch/arm/src/cxd56xx/cxd56_uart0.c b/arch/arm/src/cxd56xx/cxd56_uart0.c
index c992fdc1ab273..00a91098e5c1a 100644
--- a/arch/arm/src/cxd56xx/cxd56_uart0.c
+++ b/arch/arm/src/cxd56xx/cxd56_uart0.c
@@ -233,7 +233,7 @@ static ssize_t uart0_write(struct file *filep,
 
 int cxd56_uart0initialize(const char *devname)
 {
-  return register_driver(devname, &g_uart0fops, 0666, NULL);
+  return register_driver(devname, &g_uart0fops, 0600, NULL);
 }
 
 /****************************************************************************
diff --git a/arch/arm/src/phy62xx/phyplus_stub.c b/arch/arm/src/phy62xx/phyplus_stub.c
index 9f8d4faa1c489..d4bb98bcf1a7a 100644
--- a/arch/arm/src/phy62xx/phyplus_stub.c
+++ b/arch/arm/src/phy62xx/phyplus_stub.c
@@ -752,7 +752,7 @@ int phyplus_stub_register(void)
 {
   char devname[16];
   snprintf(devname, sizeof(devname), "/dev/phyplus");
-  return register_driver(devname, &g_stub_drvrops, 0666, NULL);
+  return register_driver(devname, &g_stub_drvrops, 0600, NULL);
 }
 
 /****************************************************************************
diff --git a/arch/arm/src/rtl8720c/ameba_hci.c b/arch/arm/src/rtl8720c/ameba_hci.c
index f446014ecc98d..90717496fcee8 100644
--- a/arch/arm/src/rtl8720c/ameba_hci.c
+++ b/arch/arm/src/rtl8720c/ameba_hci.c
@@ -507,6 +507,6 @@ static hci_dev_t g_hcidev =
 
 int amebaz_bt_hci_uart_register(const char *path)
 {
-  return register_driver(path, &g_hcidev.i_ops, 0666, &g_hcidev);
+  return register_driver(path, &g_hcidev.i_ops, 0600, &g_hcidev);
 }
 
diff --git a/arch/arm/src/sama5/sam_tsd.c b/arch/arm/src/sama5/sam_tsd.c
index 7c4bc24daeec0..b2c3e48e39294 100644
--- a/arch/arm/src/sama5/sam_tsd.c
+++ b/arch/arm/src/sama5/sam_tsd.c
@@ -1818,7 +1818,7 @@ int sam_tsd_register(struct sam_adc_s *adc, int minor)
   snprintf(devname, sizeof(devname), DEV_FORMAT, minor);
   iinfo("Registering %s\n", devname);
 
-  ret = register_driver(devname, &g_tsdops, 0666, priv);
+  ret = register_driver(devname, &g_tsdops, 0600, priv);
   if (ret < 0)
     {
       ierr("ERROR: register_driver() failed: %d\n", ret);
diff --git a/arch/arm/src/stm32f7/stm32_bbsram.c b/arch/arm/src/stm32f7/stm32_bbsram.c
index 65a5b0e510fdb..5f3f6693d7c4b 100644
--- a/arch/arm/src/stm32f7/stm32_bbsram.c
+++ b/arch/arm/src/stm32f7/stm32_bbsram.c
@@ -757,7 +757,7 @@ int stm32_bbsraminitialize(char *devpath, int *sizes)
     {
       snprintf(devname, sizeof(devname), "%s%d", devpath, i);
       ret = register_driver(devname, &g_stm32_bbsram_fops,
-                            0666, &g_bbsram[i]);
+                            0600, &g_bbsram[i]);
     }
 
   /* Disallow Access */
diff --git a/arch/arm/src/stm32h7/stm32_bbsram.c b/arch/arm/src/stm32h7/stm32_bbsram.c
index 37dc0b741b2ff..b4ed0816d10c9 100644
--- a/arch/arm/src/stm32h7/stm32_bbsram.c
+++ b/arch/arm/src/stm32h7/stm32_bbsram.c
@@ -828,7 +828,7 @@ int stm32_bbsraminitialize(char *devpath, int *sizes)
     {
       snprintf(devname, sizeof(devname), "%s%d", devpath, i);
       ret = register_driver(devname, &g_stm32_bbsram_fops,
-                            0666, &g_bbsram[i]);
+                            0600, &g_bbsram[i]);
     }
 
   /* Disallow Access */
diff --git a/arch/arm/src/tlsr82/tlsr82_spi_console.c b/arch/arm/src/tlsr82/tlsr82_spi_console.c
index d9883d2b67064..e541f837ccc0d 100644
--- a/arch/arm/src/tlsr82/tlsr82_spi_console.c
+++ b/arch/arm/src/tlsr82/tlsr82_spi_console.c
@@ -306,7 +306,7 @@ void spi_console_init(void)
 
   /* Driver register */
 
-  ret = register_driver("/dev/console", &g_consoleops, 0666, NULL);
+  ret = register_driver("/dev/console", &g_consoleops, 0600, NULL);
   if (ret < 0)
     {
       syslog(LOG_DEBUG, "register spi_console failed\n");
diff --git a/arch/renesas/src/rx65n/rx65n_sbram.c b/arch/renesas/src/rx65n/rx65n_sbram.c
index 486626b594943..491aec0d81e1f 100644
--- a/arch/renesas/src/rx65n/rx65n_sbram.c
+++ b/arch/renesas/src/rx65n/rx65n_sbram.c
@@ -662,7 +662,7 @@ int rx65n_sbraminitialize(char *devpath, int *sizes)
   for (i = 0; i < fcnt && ret >= OK; i++)
     {
       snprintf(devname, sizeof(devname), "%s%d", devpath, i);
-      ret = register_driver(devname, &g_rx65n_sbram_fops, 0666, &g_sbram[i]);
+      ret = register_driver(devname, &g_rx65n_sbram_fops, 0660, &g_sbram[i]);
     }
 
   /* Disallow Access */
diff --git a/arch/risc-v/src/common/espressif/esp_dedic_gpio.c b/arch/risc-v/src/common/espressif/esp_dedic_gpio.c
index b1df176ce8e61..55df343a1d034 100644
--- a/arch/risc-v/src/common/espressif/esp_dedic_gpio.c
+++ b/arch/risc-v/src/common/espressif/esp_dedic_gpio.c
@@ -403,7 +403,7 @@ struct file *esp_dedic_gpio_new_bundle(
   dedic_gpio_common.refs++;
 
   register_driver(config->path, &dedic_gpio_ops,
-                  0666, priv);
+                  0600, priv);
   return (struct file *)priv;
 }
 
diff --git a/arch/risc-v/src/common/espressif/esp_lp_mailbox.c b/arch/risc-v/src/common/espressif/esp_lp_mailbox.c
index 0d032678a5646..18a785378530a 100644
--- a/arch/risc-v/src/common/espressif/esp_lp_mailbox.c
+++ b/arch/risc-v/src/common/espressif/esp_lp_mailbox.c
@@ -322,6 +322,6 @@ int esp_lp_mailbox_init(void)
     }
 
   register_driver("/dev/lp_mailbox", esp_lp_mailbox_priv.ops,
-                  0666, (void *)&esp_lp_mailbox_priv);
+                  0600, (void *)&esp_lp_mailbox_priv);
   return OK;
 }
diff --git a/arch/risc-v/src/common/espressif/esp_nxdiag.c b/arch/risc-v/src/common/espressif/esp_nxdiag.c
index 3bd25518cc36f..810db01ebd459 100644
--- a/arch/risc-v/src/common/espressif/esp_nxdiag.c
+++ b/arch/risc-v/src/common/espressif/esp_nxdiag.c
@@ -306,7 +306,7 @@ static ssize_t esp_nxdiag_read(struct file *filep,
 
 static int esp_nxdiag_register(void)
 {
-  return register_driver("/dev/nxdiag", &g_nxdiagops, 0444, NULL);
+  return register_driver("/dev/nxdiag", &g_nxdiagops, 0440, NULL);
 }
 
 /****************************************************************************
diff --git a/arch/risc-v/src/common/espressif/esp_temperature_sensor.c b/arch/risc-v/src/common/espressif/esp_temperature_sensor.c
index 4393242b9e9f5..fdd7c5e9e2615 100644
--- a/arch/risc-v/src/common/espressif/esp_temperature_sensor.c
+++ b/arch/risc-v/src/common/espressif/esp_temperature_sensor.c
@@ -417,7 +417,7 @@ static void esp_temp_sensor_register(struct esp_temp_priv_s *priv)
 {
 #ifndef CONFIG_ESPRESSIF_TEMP_UORB
   register_driver(CONFIG_ESPRESSIF_TEMP_PATH, &g_esp_temp_sensor_fops,
-                  0666, priv);
+                  0660, priv);
 #else
   priv->lower.type = SENSOR_TYPE_TEMPERATURE;
   sensor_register(&priv->lower, CONFIG_ESPRESSIF_TEMP_PATH_DEVNO);
diff --git a/arch/risc-v/src/common/espressif/esp_ulp.c b/arch/risc-v/src/common/espressif/esp_ulp.c
index 69c8a01d1f0ee..fe89779bc0d4d 100644
--- a/arch/risc-v/src/common/espressif/esp_ulp.c
+++ b/arch/risc-v/src/common/espressif/esp_ulp.c
@@ -423,7 +423,7 @@ static int esp_ulp_write(struct file *filep,
 
 static void esp_ulp_register(void)
 {
-  register_driver("/dev/ulp", &g_esp_ulp_fops, 0666, NULL);
+  register_driver("/dev/ulp", &g_esp_ulp_fops, 0660, NULL);
 }
 
 /****************************************************************************
diff --git a/arch/x86/src/qemu/qemu_keypad.c b/arch/x86/src/qemu/qemu_keypad.c
index 638a5b3827642..4c1d151924a78 100644
--- a/arch/x86/src/qemu/qemu_keypad.c
+++ b/arch/x86/src/qemu/qemu_keypad.c
@@ -303,5 +303,5 @@ static ssize_t keypad_read(struct file *filep, char *buf, size_t buflen)
 
 void qemu_keypad(void)
 {
-  register_driver("/dev/keypad", &g_keypadops, 0444, NULL);
+  register_driver("/dev/keypad", &g_keypadops, 0440, NULL);
 }
diff --git a/arch/x86/src/qemu/qemu_vga.c b/arch/x86/src/qemu/qemu_vga.c
index 8ac021b14a1ac..0a1d0eb0b2694 100644
--- a/arch/x86/src/qemu/qemu_vga.c
+++ b/arch/x86/src/qemu/qemu_vga.c
@@ -588,7 +588,7 @@ int qemu_vga(void)
       return ret;
     }
 
-  register_driver("/dev/lcd", &g_vgaops, 0666, NULL);
+  register_driver("/dev/lcd", &g_vgaops, 0660, NULL);
 
   return OK;
 }
diff --git a/arch/xtensa/src/common/espressif/esp_nxdiag.c b/arch/xtensa/src/common/espressif/esp_nxdiag.c
index 70e0d7b210775..5e3df76836c18 100644
--- a/arch/xtensa/src/common/espressif/esp_nxdiag.c
+++ b/arch/xtensa/src/common/espressif/esp_nxdiag.c
@@ -313,7 +313,7 @@ static ssize_t esp_nxdiag_read(struct file *filep,
 
 static int esp_nxdiag_register(void)
 {
-  return register_driver("/dev/nxdiag", &g_nxdiagops, 0444, NULL);
+  return register_driver("/dev/nxdiag", &g_nxdiagops, 0440, NULL);
 }
 
 /****************************************************************************
diff --git a/arch/xtensa/src/common/espressif/esp_ulp.c b/arch/xtensa/src/common/espressif/esp_ulp.c
index 0f68dd251b828..57c976909088c 100644
--- a/arch/xtensa/src/common/espressif/esp_ulp.c
+++ b/arch/xtensa/src/common/espressif/esp_ulp.c
@@ -173,7 +173,7 @@ static int esp_ulp_write(struct file *filep,
 
 static void esp_ulp_register(void)
 {
-  register_driver("/dev/ulp", &g_esp_ulp_fops, 0666, NULL);
+  register_driver("/dev/ulp", &g_esp_ulp_fops, 0600, NULL);
 }
 
 /****************************************************************************
diff --git a/arch/xtensa/src/esp32/esp32_himem.c b/arch/xtensa/src/esp32/esp32_himem.c
index ec06aa5992fa7..03061f3253d91 100644
--- a/arch/xtensa/src/esp32/esp32_himem.c
+++ b/arch/xtensa/src/esp32/esp32_himem.c
@@ -249,7 +249,7 @@ int esp_himem_init(void)
 
   /* Register the character driver */
 
-  ret = register_driver("/dev/himem", &g_himemfops, 0666, NULL);
+  ret = register_driver("/dev/himem", &g_himemfops, 0600, NULL);
   if (ret < 0)
     {
       merr("ERROR: Failed to register driver: %d\n", ret);
diff --git a/arch/xtensa/src/esp32/esp32_himem_chardev.c b/arch/xtensa/src/esp32/esp32_himem_chardev.c
index 0acb814fad691..447e36a18e111 100644
--- a/arch/xtensa/src/esp32/esp32_himem_chardev.c
+++ b/arch/xtensa/src/esp32/esp32_himem_chardev.c
@@ -324,7 +324,7 @@ int himem_chardev_register(char *name, size_t size)
       return ret;
     }
 
-  ret = register_driver(dev->name, &g_fops, 0666, dev);
+  ret = register_driver(dev->name, &g_fops, 0600, dev);
   if (ret != 0)
     {
       merr("Failed to register driver. dev=%s\n", dev->name);
diff --git a/arch/xtensa/src/esp32s3/esp32s3_himem.c b/arch/xtensa/src/esp32s3/esp32s3_himem.c
index 83cd621c929fa..6b3b878d242f0 100644
--- a/arch/xtensa/src/esp32s3/esp32s3_himem.c
+++ b/arch/xtensa/src/esp32s3/esp32s3_himem.c
@@ -1070,7 +1070,7 @@ int esp_himem_init(void)
 
   /* Register the character driver */
 
-  ret = register_driver("/dev/himem", &g_himemfops, 0666, NULL);
+  ret = register_driver("/dev/himem", &g_himemfops, 0600, NULL);
   if (ret < 0)
     {
       merr("ERROR: Failed to register driver: %d\n", ret);
diff --git a/audio/audio.c b/audio/audio.c
index 1e764bf48ad9e..8ae1a1764c925 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -1863,7 +1863,7 @@ int audio_register(FAR const char *name, FAR struct audio_lowerhalf_s *dev)
   dev->priv = upper;
 
   audinfo("Registering %s\n", path);
-  return register_driver(path, &g_audioops, 0666, upper);
+  return register_driver(path, &g_audioops, 0660, upper);
 }
 
 #endif /* CONFIG_AUDIO */
diff --git a/boards/arm/cxd56xx/drivers/sensors/ak09912_scu.c b/boards/arm/cxd56xx/drivers/sensors/ak09912_scu.c
index 61031d9c84d28..5040e61ec1116 100644
--- a/boards/arm/cxd56xx/drivers/sensors/ak09912_scu.c
+++ b/boards/arm/cxd56xx/drivers/sensors/ak09912_scu.c
@@ -556,7 +556,7 @@ int ak09912_scu_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_ak09912fops, 0666, priv);
+  ret = register_driver(path, &g_ak09912fops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
diff --git a/boards/arm/cxd56xx/drivers/sensors/apds9930_scu.c b/boards/arm/cxd56xx/drivers/sensors/apds9930_scu.c
index 65b4521dbe37c..faea6c6178e12 100644
--- a/boards/arm/cxd56xx/drivers/sensors/apds9930_scu.c
+++ b/boards/arm/cxd56xx/drivers/sensors/apds9930_scu.c
@@ -974,7 +974,7 @@ int apds9930als_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_apds9930alsfops, 0666, priv);
+  ret = register_driver(path, &g_apds9930alsfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
@@ -1028,7 +1028,7 @@ int apds9930ps_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_apds9930psfops, 0666, priv);
+  ret = register_driver(path, &g_apds9930psfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
diff --git a/boards/arm/cxd56xx/drivers/sensors/bh1721fvc_scu.c b/boards/arm/cxd56xx/drivers/sensors/bh1721fvc_scu.c
index 66fb69b9a48bf..52a97f14d6872 100644
--- a/boards/arm/cxd56xx/drivers/sensors/bh1721fvc_scu.c
+++ b/boards/arm/cxd56xx/drivers/sensors/bh1721fvc_scu.c
@@ -376,7 +376,7 @@ int bh1721fvc_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_bh1721fvcfops, 0666, priv);
+  ret = register_driver(path, &g_bh1721fvcfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
diff --git a/boards/arm/cxd56xx/drivers/sensors/bh1745nuc_scu.c b/boards/arm/cxd56xx/drivers/sensors/bh1745nuc_scu.c
index a88618a446e96..384965cf1392f 100644
--- a/boards/arm/cxd56xx/drivers/sensors/bh1745nuc_scu.c
+++ b/boards/arm/cxd56xx/drivers/sensors/bh1745nuc_scu.c
@@ -510,7 +510,7 @@ int bh1745nuc_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_bh1745nucfops, 0666, priv);
+  ret = register_driver(path, &g_bh1745nucfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
diff --git a/boards/arm/cxd56xx/drivers/sensors/bm1383glv_scu.c b/boards/arm/cxd56xx/drivers/sensors/bm1383glv_scu.c
index 643e8f06fe2db..98558d46a4e7c 100644
--- a/boards/arm/cxd56xx/drivers/sensors/bm1383glv_scu.c
+++ b/boards/arm/cxd56xx/drivers/sensors/bm1383glv_scu.c
@@ -541,7 +541,7 @@ int bm1383glv_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_bm1383glvfops, 0666, priv);
+  ret = register_driver(path, &g_bm1383glvfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
diff --git a/boards/arm/cxd56xx/drivers/sensors/bm1422gmv_scu.c b/boards/arm/cxd56xx/drivers/sensors/bm1422gmv_scu.c
index 0f1ae098cc81f..5b6379c2b007a 100644
--- a/boards/arm/cxd56xx/drivers/sensors/bm1422gmv_scu.c
+++ b/boards/arm/cxd56xx/drivers/sensors/bm1422gmv_scu.c
@@ -525,7 +525,7 @@ int bm1422gmv_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_bm1422gmvfops, 0666, priv);
+  ret = register_driver(path, &g_bm1422gmvfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
diff --git a/boards/arm/cxd56xx/drivers/sensors/bmi160_scu.c b/boards/arm/cxd56xx/drivers/sensors/bmi160_scu.c
index 49406b19968f3..c42a11c1de39a 100644
--- a/boards/arm/cxd56xx/drivers/sensors/bmi160_scu.c
+++ b/boards/arm/cxd56xx/drivers/sensors/bmi160_scu.c
@@ -828,7 +828,7 @@ static int bmi160_devregister(const char *devpath,
 
 #endif
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, fops, 0666, priv);
+  ret = register_driver(path, fops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
diff --git a/boards/arm/cxd56xx/drivers/sensors/bmp280_scu.c b/boards/arm/cxd56xx/drivers/sensors/bmp280_scu.c
index 8a618921039a0..2db74ed0765db 100644
--- a/boards/arm/cxd56xx/drivers/sensors/bmp280_scu.c
+++ b/boards/arm/cxd56xx/drivers/sensors/bmp280_scu.c
@@ -931,7 +931,7 @@ int bmp280press_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_bmp280pressfops, 0666, priv);
+  ret = register_driver(path, &g_bmp280pressfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
@@ -982,7 +982,7 @@ int bmp280temp_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_bmp280tempfops, 0666, priv);
+  ret = register_driver(path, &g_bmp280tempfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
diff --git a/boards/arm/cxd56xx/drivers/sensors/cxd5610_gnss.c b/boards/arm/cxd56xx/drivers/sensors/cxd5610_gnss.c
index 3944e26fdbd7a..2e11c5b7db318 100644
--- a/boards/arm/cxd56xx/drivers/sensors/cxd5610_gnss.c
+++ b/boards/arm/cxd56xx/drivers/sensors/cxd5610_gnss.c
@@ -2268,7 +2268,7 @@ int cxd5610_gnss_register(const char *devpath,
 
   /* Register the character driver */
 
-  ret = register_driver(devpath, &g_cxd5610fops, 0666, priv);
+  ret = register_driver(devpath, &g_cxd5610fops, 0660, priv);
   if (ret < 0)
     {
       snerr("ERROR: Failed to register driver: %d\n", ret);
diff --git a/boards/arm/cxd56xx/drivers/sensors/kx022_scu.c b/boards/arm/cxd56xx/drivers/sensors/kx022_scu.c
index f8ba05638c85e..bb569bcb45ddb 100644
--- a/boards/arm/cxd56xx/drivers/sensors/kx022_scu.c
+++ b/boards/arm/cxd56xx/drivers/sensors/kx022_scu.c
@@ -510,7 +510,7 @@ int kx022_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_kx022fops, 0666, priv);
+  ret = register_driver(path, &g_kx022fops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
diff --git a/boards/arm/cxd56xx/drivers/sensors/lt1pa01_scu.c b/boards/arm/cxd56xx/drivers/sensors/lt1pa01_scu.c
index 096a58db51f32..41cf599286fdb 100644
--- a/boards/arm/cxd56xx/drivers/sensors/lt1pa01_scu.c
+++ b/boards/arm/cxd56xx/drivers/sensors/lt1pa01_scu.c
@@ -814,7 +814,7 @@ int lt1pa01als_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_lt1pa01alsfops, 0666, priv);
+  ret = register_driver(path, &g_lt1pa01alsfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
@@ -868,7 +868,7 @@ int lt1pa01prox_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_lt1pa01proxfops, 0666, priv);
+  ret = register_driver(path, &g_lt1pa01proxfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
diff --git a/boards/arm/cxd56xx/drivers/sensors/rpr0521rs_scu.c b/boards/arm/cxd56xx/drivers/sensors/rpr0521rs_scu.c
index 86c261e9fd723..894afa6721472 100644
--- a/boards/arm/cxd56xx/drivers/sensors/rpr0521rs_scu.c
+++ b/boards/arm/cxd56xx/drivers/sensors/rpr0521rs_scu.c
@@ -931,7 +931,7 @@ int rpr0521rsals_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_rpr0521rsalsfops, 0666, priv);
+  ret = register_driver(path, &g_rpr0521rsalsfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
@@ -985,7 +985,7 @@ int rpr0521rsps_register(const char *devpath, int minor,
   /* Register the character driver */
 
   snprintf(path, sizeof(path), "%s%d", devpath, minor);
-  ret = register_driver(path, &g_rpr0521rspsfops, 0666, priv);
+  ret = register_driver(path, &g_rpr0521rspsfops, 0660, priv);
   if (ret < 0)
     {
       snerr("Failed to register driver: %d\n", ret);
diff --git a/boards/arm/kl/freedom-kl25z/src/kl_tsi.c b/boards/arm/kl/freedom-kl25z/src/kl_tsi.c
index 7a74b27549259..ba4d9d23aa5f4 100644
--- a/boards/arm/kl/freedom-kl25z/src/kl_tsi.c
+++ b/boards/arm/kl/freedom-kl25z/src/kl_tsi.c
@@ -244,7 +244,7 @@ void kl_tsi_initialize(void)
 
   /* And finally register the TSI character driver */
 
-  register_driver("/dev/tsi", &g_tsi_ops, 0444, NULL);
+  register_driver("/dev/tsi", &g_tsi_ops, 0440, NULL);
 }
 
 #endif /* CONFIG_KL_TSI */
diff --git a/boards/arm/kl/freedom-kl26z/src/kl_tsi.c b/boards/arm/kl/freedom-kl26z/src/kl_tsi.c
index 0d2c2c2e9c8a5..565d703837d65 100644
--- a/boards/arm/kl/freedom-kl26z/src/kl_tsi.c
+++ b/boards/arm/kl/freedom-kl26z/src/kl_tsi.c
@@ -245,7 +245,7 @@ void kl_tsi_initialize(void)
 
   /* And finally register the TSI character driver */
 
-  register_driver("/dev/tsi", &g_tsi_ops, 0444, NULL);
+  register_driver("/dev/tsi", &g_tsi_ops, 0440, NULL);
 }
 
 #endif /* CONFIG_KL_TSI */
diff --git a/boards/arm/sam34/sam4l-xplained/src/sam_slcd.c b/boards/arm/sam34/sam4l-xplained/src/sam_slcd.c
index 0d621314e5c7a..c669a7c43a46e 100644
--- a/boards/arm/sam34/sam4l-xplained/src/sam_slcd.c
+++ b/boards/arm/sam34/sam4l-xplained/src/sam_slcd.c
@@ -1267,7 +1267,7 @@ int sam_slcd_initialize(void)
 
       /* Register the LCD device driver */
 
-      ret = register_driver("/dev/slcd0", &g_slcdops, 0644, &g_slcdstate);
+      ret = register_driver("/dev/slcd0", &g_slcdops, 0640, &g_slcdstate);
       g_slcdstate.initialized = true;
 
       /* Turn on the backlight */
diff --git a/boards/arm/stm32f4/mikroe-stm32f4/src/stm32_touchscreen.c b/boards/arm/stm32f4/mikroe-stm32f4/src/stm32_touchscreen.c
index c1ca271395472..22a7b7b75bff0 100644
--- a/boards/arm/stm32f4/mikroe-stm32f4/src/stm32_touchscreen.c
+++ b/boards/arm/stm32f4/mikroe-stm32f4/src/stm32_touchscreen.c
@@ -1508,7 +1508,7 @@ int stm32_tsc_setup(int minor)
   snprintf(devname, sizeof(devname), DEV_FORMAT, minor);
   iinfo("Registering %s\n", devname);
 
-  ret = register_driver(devname, &g_tc_fops, 0666, priv);
+  ret = register_driver(devname, &g_tc_fops, 0660, priv);
   if (ret < 0)
     {
       ierr("ERROR: register_driver() failed: %d\n", ret);
diff --git a/boards/mips/pic32mx/pic32mx7mmb/src/pic32_touchscreen.c b/boards/mips/pic32mx/pic32mx7mmb/src/pic32_touchscreen.c
index 144f838f50e5f..e9773e4a0f6fd 100644
--- a/boards/mips/pic32mx/pic32mx7mmb/src/pic32_touchscreen.c
+++ b/boards/mips/pic32mx/pic32mx7mmb/src/pic32_touchscreen.c
@@ -1371,7 +1371,7 @@ int pic32mx_tsc_setup(int minor)
   snprintf(devname, sizeof(devname), DEV_FORMAT, minor);
   iinfo("Registering %s\n", devname);
 
-  ret = register_driver(devname, &g_tc_fops, 0666, priv);
+  ret = register_driver(devname, &g_tc_fops, 0660, priv);
   if (ret < 0)
     {
       ierr("ERROR: register_driver() failed: %d\n", ret);
diff --git a/crypto/cryptodev.c b/crypto/cryptodev.c
index a6ad2be409254..d624e14d330b1 100644
--- a/crypto/cryptodev.c
+++ b/crypto/cryptodev.c
@@ -1174,7 +1174,7 @@ static int csefree(FAR struct csession *cse)
 
 void devcrypto_register(void)
 {
-  register_driver("/dev/crypto", &g_cryptoops, 0666, NULL);
+  register_driver("/dev/crypto", &g_cryptoops, 0660, NULL);
 
 #ifdef CONFIG_CRYPTO_CRYPTODEV_SOFTWARE_CRYPTO
   swcr_init();
diff --git a/drivers/1wire/1wire_ds2xxx.c b/drivers/1wire/1wire_ds2xxx.c
index 980e595921f5f..fcabc35188e7b 100644
--- a/drivers/1wire/1wire_ds2xxx.c
+++ b/drivers/1wire/1wire_ds2xxx.c
@@ -826,5 +826,5 @@ int ds2xxx_initialize(FAR struct onewire_dev_s *dev,
   priv->master->dev = dev;
   priv->devtype     = devtype;
 
-  return register_driver(devname, &g_ds2xxx_fops, 0666, priv);
+  return register_driver(devname, &g_ds2xxx_fops, 0600, priv);
 }
diff --git a/drivers/aie/ai_engine.c b/drivers/aie/ai_engine.c
index 3f2fec152686e..d3dded5e9851d 100644
--- a/drivers/aie/ai_engine.c
+++ b/drivers/aie/ai_engine.c
@@ -243,7 +243,7 @@ int aie_register(FAR const char *path,
 
   /* Register the aie device */
 
-  ret = register_driver(path, &g_aie_ops, 0666, upper);
+  ret = register_driver(path, &g_aie_ops, 0600, upper);
   if (ret < 0)
     {
       _err("register aie driver failed: %d\n", ret);
diff --git a/drivers/analog/adc.c b/drivers/analog/adc.c
index 9637d65cc68b7..802d1d7c5e546 100644
--- a/drivers/analog/adc.c
+++ b/drivers/analog/adc.c
@@ -803,7 +803,7 @@ int adc_register(FAR const char *path, FAR struct adc_dev_s *dev)
 
   /* Register the ADC character driver */
 
-  ret = register_driver(path, &g_adc_fops, 0444, dev);
+  ret = register_driver(path, &g_adc_fops, 0400, dev);
   if (ret < 0)
     {
       if (alloc_channel)
diff --git a/drivers/analog/ads1242.c b/drivers/analog/ads1242.c
index 150dc563f1d7c..8333e8275aa04 100644
--- a/drivers/analog/ads1242.c
+++ b/drivers/analog/ads1242.c
@@ -600,7 +600,7 @@ int ads1242_register(FAR const char *devpath, FAR struct spi_dev_s *spi,
 
   /* Register the character driver */
 
-  ret = register_driver(devpath, &g_ads1242_fops, 0666, priv);
+  ret = register_driver(devpath, &g_ads1242_fops, 0600, priv);
   if (ret < 0)
     {
        _err("ERROR: Failed to register driver: %d\n", ret);
diff --git a/drivers/analog/ads7046.c b/drivers/analog/ads7046.c
index 36738779b69ad..6b992e73409cd 100644
--- a/drivers/analog/ads7046.c
+++ b/drivers/analog/ads7046.c
@@ -270,7 +270,7 @@ int ads7046_register(FAR const char *devpath, FAR struct spi_dev_s *spi,
 
   /* Register the character driver */
 
-  int ret = register_driver(devpath, &ads7046_fops, 0666, priv);
+  int ret = register_driver(devpath, &ads7046_fops, 0600, priv);
   if (ret < 0)
     {
       aerr("ERROR: Failed to register driver: %s (%d)\n", strerror(-ret),
diff --git a/drivers/analog/comp.c b/drivers/analog/comp.c
index 6cd70f8870017..8955904f9e08a 100644
--- a/drivers/analog/comp.c
+++ b/drivers/analog/comp.c
@@ -372,7 +372,7 @@ int comp_register(FAR const char *path, FAR struct comp_dev_s *dev)
 
   /* Register the COMP character driver */
 
-  ret = register_driver(path, &g_comp_fops, 0444, dev);
+  ret = register_driver(path, &g_comp_fops, 0400, dev);
   if (ret < 0)
     {
       nxmutex_destroy(&dev->ad_lock);
diff --git a/drivers/analog/dac.c b/drivers/analog/dac.c
index 722ee5c48fb59..f22ccb7a4ca76 100644
--- a/drivers/analog/dac.c
+++ b/drivers/analog/dac.c
@@ -503,5 +503,5 @@ int dac_register(FAR const char *path, FAR struct dac_dev_s *dev)
 
   dev->ad_ops->ao_reset(dev);
 
-  return register_driver(path, &g_dac_fops, 0222, dev);
+  return register_driver(path, &g_dac_fops, 0200, dev);
 }
diff --git a/drivers/analog/hx711.c b/drivers/analog/hx711.c
index 8e549a173083f..f550778936eb4 100644
--- a/drivers/analog/hx711.c
+++ b/drivers/analog/hx711.c
@@ -949,7 +949,7 @@ int hx711_register(unsigned char minor, FAR struct hx711_lower_s *lower)
     }
 
   snprintf(devname, sizeof(devname), DEVNAME_FMT, minor);
-  ret = register_driver(devname, &g_hx711_fops, 0666, dev);
+  ret = register_driver(devname, &g_hx711_fops, 0600, dev);
   if (ret)
     {
       kmm_free(dev);
diff --git a/drivers/analog/opamp.c b/drivers/analog/opamp.c
index 0d83e9d915b7b..a7cfc9a9917d9 100644
--- a/drivers/analog/opamp.c
+++ b/drivers/analog/opamp.c
@@ -211,7 +211,7 @@ int opamp_register(FAR const char *path, FAR struct opamp_dev_s *dev)
 
   /* Register the OPAMP character driver */
 
-  ret = register_driver(path, &g_opamp_fops, 0444, dev);
+  ret = register_driver(path, &g_opamp_fops, 0400, dev);
   if (ret < 0)
     {
       nxmutex_destroy(&dev->ad_closelock);
diff --git a/drivers/audio/tone.c b/drivers/audio/tone.c
index df4d4bafadd28..784afc28ab033 100644
--- a/drivers/audio/tone.c
+++ b/drivers/audio/tone.c
@@ -966,7 +966,7 @@ int tone_register(FAR const char *path, FAR struct pwm_lowerhalf_s *tone,
   /* Register the PWM device */
 
   audinfo("Registering %s\n", path);
-  return register_driver(path, &g_toneops, 0666, upper);
+  return register_driver(path, &g_toneops, 0600, upper);
 }
 
 #endif /* CONFIG_AUDIO_TONE */
diff --git a/drivers/bch/bchdev_register.c b/drivers/bch/bchdev_register.c
index 8262b55644891..92ff36015692d 100644
--- a/drivers/bch/bchdev_register.c
+++ b/drivers/bch/bchdev_register.c
@@ -69,7 +69,7 @@ int bchdev_register(FAR const char *blkdev, FAR const char *chardev,
 
   /* Then setup the character device */
 
-  ret = register_driver(chardev, &g_bch_fops, 0666, handle);
+  ret = register_driver(chardev, &g_bch_fops, 0600, handle);
   if (ret < 0)
     {
       ferr("ERROR: register_driver failed: %d\n", -ret);
diff --git a/drivers/can/can.c b/drivers/can/can.c
index 987100f60c50b..624852c1a1ee8 100644
--- a/drivers/can/can.c
+++ b/drivers/can/can.c
@@ -1291,7 +1291,7 @@ int can_register(FAR const char *path, FAR struct can_dev_s *dev)
   /* Register the CAN device */
 
   caninfo("Registering %s\n", path);
-  return register_driver(path, &g_canops, 0666, dev);
+  return register_driver(path, &g_canops, 0600, dev);
 }
 
 /****************************************************************************
diff --git a/drivers/contactless/mfrc522.c b/drivers/contactless/mfrc522.c
index db03cc79004d2..003f671e625a6 100644
--- a/drivers/contactless/mfrc522.c
+++ b/drivers/contactless/mfrc522.c
@@ -1682,7 +1682,7 @@ int mfrc522_register(FAR const char *devpath, FAR struct spi_dev_s *spi)
 
   /* Register the character driver */
 
-  ret = register_driver(devpath, &g_mfrc522fops, 0666, dev);
+  ret = register_driver(devpath, &g_mfrc522fops, 0600, dev);
   if (ret < 0)
     {
       ctlserr("ERROR: Failed to register driver: %d\n", ret);
diff --git a/drivers/contactless/pn532.c b/drivers/contactless/pn532.c
index 88e631bd9efd2..d0c7cb8fd3dc3 100644
--- a/drivers/contactless/pn532.c
+++ b/drivers/contactless/pn532.c
@@ -1158,7 +1158,7 @@ int pn532_register(FAR const char *devpath, FAR struct spi_dev_s *spi,
 
   /* Register the character driver */
 
-  ret = register_driver(devpath, &g_pn532fops, 0666, dev);
+  ret = register_driver(devpath, &g_pn532fops, 0600, dev);
   if (ret < 0)
     {
       ctlserr("ERROR: Failed to register driver: %d\n", ret);
diff --git a/drivers/coresight/coresight_tmc_etr.c b/drivers/coresight/coresight_tmc_etr.c
index 2b3d0f93ceda3..de953379cda6c 100644
--- a/drivers/coresight/coresight_tmc_etr.c
+++ b/drivers/coresight/coresight_tmc_etr.c
@@ -484,7 +484,7 @@ int tmc_etr_register(FAR struct coresight_tmc_dev_s *tmcdev,
     }
 
   snprintf(pathname, sizeof(pathname), "/dev/%s", desc->name);
-  ret = register_driver(pathname, &g_tmc_fops, 0444, tmcdev);
+  ret = register_driver(pathname, &g_tmc_fops, 0400, tmcdev);
   if (ret < 0)
     {
       cserr("%s:driver register failed\n", desc->name);
diff --git a/drivers/crypto/dev_urandom.c b/drivers/crypto/dev_urandom.c
index e3e71f726197e..50edb79ff7820 100644
--- a/drivers/crypto/dev_urandom.c
+++ b/drivers/crypto/dev_urandom.c
@@ -324,7 +324,7 @@ void devurandom_register(void)
   g_prng.state.z = g_prng.state.x << 25;
 #endif
 
-  register_driver("/dev/urandom", &g_urand_fops, 0666, NULL);
+  register_driver("/dev/urandom", &g_urand_fops, 0600, NULL);
 }
 
 #endif /* CONFIG_DEV_URANDOM && CONFIG_DEV_URANDOM_ARCH */
diff --git a/drivers/crypto/rng90.c b/drivers/crypto/rng90.c
index 3c7b065fe6979..de4cb25375d68 100644
--- a/drivers/crypto/rng90.c
+++ b/drivers/crypto/rng90.c
@@ -359,7 +359,7 @@ int rng90_register(FAR const char *devpath, FAR struct i2c_master_s *i2c,
 
   /* Register the character driver */
 
-  ret = register_driver(devpath, &g_rng90_fops, 0666, priv);
+  ret = register_driver(devpath, &g_rng90_fops, 0600, priv);
   if (ret < 0)
     {
       crypterr("ERROR: Failed to register driver: %d\n", ret);
diff --git a/drivers/crypto/se05x.c b/drivers/crypto/se05x.c
index e1104e31694a9..63376cb859fed 100644
--- a/drivers/crypto/se05x.c
+++ b/drivers/crypto/se05x.c
@@ -263,7 +263,7 @@ int se05x_register(FAR const char *devpath, FAR struct i2c_master_s *i2c,
 
   /* Register driver */
 
-  ret = register_driver(devpath, &g_fops, 0666, priv);
+  ret = register_driver(devpath, &g_fops, 0600, priv);
   if (ret < 0)
     {
       crypterr("ERROR: Failed to register driver: %d\n", ret);
diff --git a/drivers/eeprom/i2c_xx24xx.c b/drivers/eeprom/i2c_xx24xx.c
index fe9ef045a2f46..3cd97cc4cfd7f 100644
--- a/drivers/eeprom/i2c_xx24xx.c
+++ b/drivers/eeprom/i2c_xx24xx.c
@@ -1086,7 +1086,7 @@ int ee24xx_initialize(FAR struct i2c_master_s *bus, uint8_t devaddr,
 
   strlcpy(uuidname, devname, size);
   strlcat(uuidname, ".uuid", size);
-  ret = register_driver(uuidname, &g_at24cs_uuid_fops, 0444, eedev);
+  ret = register_driver(uuidname, &g_at24cs_uuid_fops, 0400, eedev);
 
   kmm_free(uuidname);
 
@@ -1097,6 +1097,6 @@ int ee24xx_initialize(FAR struct i2c_master_s *bus, uint8_t devaddr,
     }
 #endif
 
-  return register_driver_with_size(devname, &g_ee24xx_fops, 0666, eedev,
+  return register_driver_with_size(devname, &g_ee24xx_fops, 0600, eedev,
                                    eedev->size);
 }
diff --git a/drivers/eeprom/spi_xx25xx.c b/drivers/eeprom/spi_xx25xx.c
index f4bb68dd9157a..ffbf992add3a7 100644
--- a/drivers/eeprom/spi_xx25xx.c
+++ b/drivers/eeprom/spi_xx25xx.c
@@ -1520,7 +1520,7 @@ int ee25xx_initialize(FAR struct spi_dev_s *dev, uint16_t spi_devid,
       "readonly %d\n", devname, eedev->size, eedev->pgsize,
       eedev->addrlen, eedev->readonly);
 
-  return register_driver(devname, &g_ee25xx_fops, 0666, eedev);
+  return register_driver(devname, &g_ee25xx_fops, 0600, eedev);
 }
 
 /****************************************************************************
diff --git a/drivers/efuse/efuse.c b/drivers/efuse/efuse.c
index 65de6d3bc834d..29afbe7180112 100644
--- a/drivers/efuse/efuse.c
+++ b/drivers/efuse/efuse.c
@@ -303,7 +303,7 @@ FAR void *efuse_register(FAR const char *path,
 
   /* Register the efuse timer device */
 
-  ret = register_driver(path, &g_efuseops, 0666, upper);
+  ret = register_driver(path, &g_efuseops, 0600, upper);
   if (ret < 0)
     {
       merr("register_driver failed: %d\n", ret);
diff --git a/drivers/i2c/i2c_driver.c b/drivers/i2c/i2c_driver.c
index e68e985959652..a9f3bb291b97f 100644
--- a/drivers/i2c/i2c_driver.c
+++ b/drivers/i2c/i2c_driver.c
@@ -416,7 +416,7 @@ int i2c_register(FAR struct i2c_master_s *i2c, int bus)
       /* Create the character device name */
 
       snprintf(devname, sizeof(devname), DEVNAME_FMT, bus);
-      ret = register_driver(devname, &g_i2cdrvr_fops, 0666, priv);
+      ret = register_driver(devname, &g_i2cdrvr_fops, 0600, priv);
       if (ret < 0)
         {
           /* Free the device structure if we failed to create the character
diff --git a/drivers/i2c/i2c_slave_driver.c b/drivers/i2c/i2c_slave_driver.c
index 0e46ebaa5cf9f..90b4c5f29ee4c 100644
--- a/drivers/i2c/i2c_slave_driver.c
+++ b/drivers/i2c/i2c_slave_driver.c
@@ -567,7 +567,7 @@ int i2c_slave_register(FAR struct i2c_slave_s *dev, int bus, int addr,
     }
 
   snprintf(devname, sizeof(devname), DEVNAME_FMT, bus);
-  ret = register_driver(devname, &g_i2cslavefops, 0666, priv);
+  ret = register_driver(devname, &g_i2cslavefops, 0600, priv);
   if (ret < 0)
     {
       kmm_free(priv);
diff --git a/drivers/i2s/i2schar.c b/drivers/i2s/i2schar.c
index 56a3d964382f0..ca91b8a363524 100644
--- a/drivers/i2s/i2schar.c
+++ b/drivers/i2s/i2schar.c
@@ -692,7 +692,7 @@ int i2schar_register(FAR struct i2s_dev_s *i2s, int minor)
       /* Create the character device name */
 
       snprintf(devname, sizeof(devname), DEVNAME_FMT, minor);
-      ret = register_driver(devname, &g_i2schar_fops, 0666, priv);
+      ret = register_driver(devname, &g_i2schar_fops, 0600, priv);
       if (ret < 0)
         {
           /* Free the device structure if we failed to create the character