Recover host enumeration from zero length descriptors

1 files changed, 7 insertions, 0 deletions

diff --git a/src/host/usbh.c b/src/host/usbh.c
index b5df29f50..1b45fd1be 100644
--- a/src/host/usbh.c
+++ b/src/host/usbh.c
@@ -1645,6 +1645,13 @@ static bool _parse_configuration_descriptor(uint8_t dev_addr, tusb_desc_configur
       //          desc_iad->bFunctionClass  == desc_itf->bInterfaceClass);
     }
 
+    if ( 0 == tu_desc_len(p_desc) ) {
+      // A zero length descriptor indicates that the wTotalLength field is wrong.
+      // Parsed interfaces should still be usable
+      TU_LOG_USBH("Encountered a zero-length descriptor after %u bytes\r\n", (uint32_t)p_desc - (uint32_t)desc_cfg);
+      break;
+    }
+
     TU_ASSERT( TUSB_DESC_INTERFACE == tu_desc_type(p_desc) );
     tusb_desc_interface_t const* desc_itf = (tusb_desc_interface_t const*) p_desc;