Validate open() mode

Author: dhalbert

extmod/vfs_fat_file.c

@@ -139,39 +139,59 @@ STATIC const mp_arg_t file_open_args[] = {
 STATIC mp_obj_t file_open(fs_user_mount_t *vfs, const mp_obj_type_t *type, mp_arg_val_t *args) {
     int mode = 0;
     const char *mode_s = mp_obj_str_get_str(args[1].u_obj);
-    // TODO make sure only one of r, w, x, a, and b, t are specified
+    uint32_t rwxa_count = 0;
+    uint32_t bt_count = 0;
+    uint32_t plus_count = 0;
+    bool bad_mode = false;
     while (*mode_s) {
         switch (*mode_s++) {
             case 'r':
                 mode |= FA_READ;
+                rwxa_count++;
                 break;
             case 'w':
                 mode |= FA_WRITE | FA_CREATE_ALWAYS;
+                rwxa_count++;
                 break;
             case 'x':
                 mode |= FA_WRITE | FA_CREATE_NEW;
+                rwxa_count++;
                 break;
             case 'a':
                 mode |= FA_WRITE | FA_OPEN_ALWAYS;
+                rwxa_count++;
                 break;
             case '+':
                 mode |= FA_READ | FA_WRITE;
+                plus_count++;
                 break;
             #if MICROPY_PY_IO_FILEIO
             case 'b':
+                bt_count++;
                 type = &mp_type_vfs_fat_fileio;
                 break;
             #endif
             case 't':
+                bt_count++;
                 type = &mp_type_vfs_fat_textio;
                 break;
+            default:
+                bad_mode = true;
+                mp_raise_ValueError(translate("Invalid mode"));
+                break;
         }
     }
+
+    if (rwxa_count != 1 || plus_count > 1 || bt_count > 1 || bad_mode) {
+        mp_raise_ValueError(translate("Invalid mode"));
+    }
+
     assert(vfs != NULL);
     if ((mode & FA_WRITE) != 0 && !filesystem_is_writable_by_python(vfs)) {
         mp_raise_OSError(MP_EROFS);
     }
 
+
     pyb_file_obj_t *o = m_new_obj_with_finaliser(pyb_file_obj_t);
     o->base.type = type;
 

locale/circuitpython.pot

@@ -1370,6 +1370,10 @@ msgstr ""
 msgid "Invalid memory access."
 msgstr ""
 
+#: extmod/vfs_fat_file.c
+msgid "Invalid mode"
+msgstr ""
+
 #: ports/espressif/common-hal/wifi/Radio.c
 msgid "Invalid multicast MAC address"
 msgstr ""
@@ -3992,22 +3996,26 @@ msgstr ""
 msgid "pow() with 3 arguments requires integers"
 msgstr ""
 
+#: ports/espressif/boards/adafruit_esp32s2_camera/mpconfigboard.h
 #: ports/espressif/boards/adafruit_feather_esp32s2/mpconfigboard.h
 #: ports/espressif/boards/adafruit_feather_esp32s2_tft/mpconfigboard.h
 #: ports/espressif/boards/adafruit_feather_esp32s2_tftback_nopsram/mpconfigboard.h
 #: ports/espressif/boards/adafruit_funhouse/mpconfigboard.h
 #: ports/espressif/boards/adafruit_magtag_2.9_grayscale/mpconfigboard.h
 #: ports/espressif/boards/adafruit_metro_esp32s2/mpconfigboard.h
 #: ports/espressif/boards/adafruit_qtpy_esp32s2/mpconfigboard.h
+#: ports/espressif/boards/adafruit_qtpy_esp32s3_nopsram/mpconfigboard.h
 #: ports/espressif/boards/ai_thinker_esp32-c3s/mpconfigboard.h
 #: ports/espressif/boards/ai_thinker_esp_12k_nodemcu/mpconfigboard.h
 #: ports/espressif/boards/artisense_rd00/mpconfigboard.h
 #: ports/espressif/boards/atmegazero_esp32s2/mpconfigboard.h
 #: ports/espressif/boards/crumpspace_crumps2/mpconfigboard.h
 #: ports/espressif/boards/electroniccats_bastwifi/mpconfigboard.h
+#: ports/espressif/boards/espressif_esp32c3_devkitm_1_n4/mpconfigboard.h
 #: ports/espressif/boards/espressif_esp32s3_box/mpconfigboard.h
-#: ports/espressif/boards/espressif_esp32s3_devkitc_1/mpconfigboard.h
-#: ports/espressif/boards/espressif_esp32s3_devkitc_1_nopsram/mpconfigboard.h
+#: ports/espressif/boards/espressif_esp32s3_devkitc_1_n8/mpconfigboard.h
+#: ports/espressif/boards/espressif_esp32s3_devkitc_1_n8r2/mpconfigboard.h
+#: ports/espressif/boards/espressif_esp32s3_devkitc_1_n8r8/mpconfigboard.h
 #: ports/espressif/boards/espressif_hmi_devkit_1/mpconfigboard.h
 #: ports/espressif/boards/espressif_kaluga_1.3/mpconfigboard.h
 #: ports/espressif/boards/espressif_kaluga_1/mpconfigboard.h