diff --git a/components/fatfs/port/freertos/ffsystem.c b/components/fatfs/port/freertos/ffsystem.c
index 37c31de3fe3..4a6e0140d8a 100644
--- a/components/fatfs/port/freertos/ffsystem.c
+++ b/components/fatfs/port/freertos/ffsystem.c
@@ -122,7 +122,7 @@ int ff_mutex_create (	/* Returns 1:Function succeeded or 0:Could not create the
 /  semaphore of the volume created with ff_mutex_create function.
 */
 
-void ff_mutex_delete (	/* Returns 1:Function succeeded or 0:Could not delete due to an error */
+void ff_mutex_delete (
 	int vol				/* Mutex ID: Volume mutex (0 to FF_VOLUMES - 1) or system mutex (FF_VOLUMES) */
 )
 {
@@ -138,7 +138,10 @@ void ff_mutex_delete (	/* Returns 1:Function succeeded or 0:Could not delete due
 	OSMutexDel(Mutex[vol], OS_DEL_ALWAYS, &err);
 
 #elif OS_TYPE == 3	/* FreeRTOS */
-	vSemaphoreDelete(Mutex[vol]);
+	if (Mutex[vol] != NULL) {
+		vSemaphoreDelete(Mutex[vol]);
+		Mutex[vol] = NULL;	/* Prevent use-after-delete in ff_mutex_take/ff_mutex_give */
+	}
 
 #elif OS_TYPE == 4	/* CMSIS-RTOS */
 	osMutexDelete(Mutex[vol]);
@@ -167,10 +170,13 @@ int ff_mutex_take (	/* Returns 1:Succeeded or 0:Timeout */
 #elif OS_TYPE == 2	/* uC/OS-II */
 	OS_ERR err;
 
-	OSMutexPend(Mutex[vol], FF_FS_TIMEOUT, &err));
+	OSMutexPend(Mutex[vol], FF_FS_TIMEOUT, &err);
 	return (int)(err == OS_NO_ERR);
 
 #elif OS_TYPE == 3	/* FreeRTOS */
+	if (vol < 0 || vol > FF_VOLUMES || Mutex[vol] == NULL) {
+		return 0;	/* No volume mounted or mutex not created -> treat as timeout */
+	}
 	return (int)(xSemaphoreTake(Mutex[vol], FF_FS_TIMEOUT) == pdTRUE);
 
 #elif OS_TYPE == 4	/* CMSIS-RTOS */
@@ -201,7 +207,9 @@ void ff_mutex_give (
 	OSMutexPost(Mutex[vol]);
 
 #elif OS_TYPE == 3	/* FreeRTOS */
-	xSemaphoreGive(Mutex[vol]);
+	if (vol >= 0 && vol <= FF_VOLUMES && Mutex[vol] != NULL) {
+		xSemaphoreGive(Mutex[vol]);
+	}
 
 #elif OS_TYPE == 4	/* CMSIS-RTOS */
 	osMutexRelease(Mutex[vol]);
diff --git a/components/fatfs/vfs/vfs_fat_spiflash.c b/components/fatfs/vfs/vfs_fat_spiflash.c
index aebc9a4923f..b1764a049ac 100644
--- a/components/fatfs/vfs/vfs_fat_spiflash.c
+++ b/components/fatfs/vfs/vfs_fat_spiflash.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2025 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2026 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -215,6 +215,11 @@ esp_err_t esp_vfs_fat_spiflash_mount_rw_wl(const char* base_path,
     return ESP_OK;
 
 fail:
+    /* Unmount FatFs volume if we had registered and attempted mount (e.g. s_f_mount_rw
+     * failed). Otherwise FatFs[vol] can be left set with a dangling pointer after
+     * esp_vfs_fat_unregister_path frees the context, and the volume mutex stays
+     * created; a later f_getfree then crashes in lock_volume / ff_mutex_take. */
+    f_mount(0, drv, 0);
     esp_vfs_fat_unregister_path(base_path);
     ff_diskio_unregister(pdrv);
     free(ctx);
@@ -390,6 +395,7 @@ esp_err_t esp_vfs_fat_spiflash_mount_ro(const char* base_path,
     return ESP_OK;
 
 fail:
+    f_mount(0, drv, 0);   /* Unmount on failed mount so FatFs[vol] and mutex are cleaned up */
     esp_vfs_fat_unregister_path(base_path);
     ff_diskio_unregister(pdrv);
     return ret;