Memory leak in vfs_fat_sdmmc#esp_vfs_fat_sdmmc_mount (IDFGH-1969)

[BeckerMarkus]

A small amount of memory allocated in esp_vfs_fat_sdmmc_mount will never be released, if the proc errors out via goto fail.

In esp_vfs_fat_sdmmc_mount, s_base_path = strdup(base_path) allocates memory. Then, if there is an error, the function performs a goto fail pattern, where all previously allocated resources should be released - it just misses s_base_path.

While the leak is small, there are scenarios where esp_vfs_fat_sdmmc_mount gets called multiple times and fails because the user inserted an invalid SD card
or the app uses a poor mans strategy to query for a plugged SD card by polling esp_vfs_fat_sdmmc_mount.

And easy to fix obviously:

--- /tmp/meld-tmpl80zweco
+++ /home/esp32/esp/esp-idf/components/fatfs/src/vfs_fat_sdmmc.c
@@ -158,6 +158,8 @@
     ff_diskio_unregister(pdrv);
     free(s_card);
     s_card = NULL;
+    free( s_base_path);
+    s_base_path = NULL;
     return err;
 }

Best,
Markus

[dobairoland]

Thank you @BeckerMarkus for reporting this and giving a hint to fix it. We'll look into this...