From f0a23398225d828b8d1ae7438979760b47404cd6 Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Mon, 9 May 2022 14:46:50 -0400
Subject: [PATCH] canboot_main: Make sure to not overwrite the bootloader
 itself

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---
 src/canboot_main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/canboot_main.c b/src/canboot_main.c
index f441c9f..a5e1a54 100644
--- a/src/canboot_main.c
+++ b/src/canboot_main.c
@@ -86,6 +86,10 @@ process_write_block(uint32_t* data, uint8_t data_len) {
         return;
     }
     uint32_t block_address = le32_to_cpu(data[0]);
+    if (block_address < CONFIG_APPLICATION_START) {
+        canboot_sendf(cerr, 8);
+        return;
+    }
     uint32_t flash_page_size = flash_get_page_size();
     uint32_t page_pos = block_address % flash_page_size;
     memcpy(&page_buffer[page_pos], (uint8_t *)&data[1], CONFIG_BLOCK_SIZE);