From cda38d2876d6a12e9b52fcdd1e006744e1037e57 Mon Sep 17 00:00:00 2001
From: stefanrueger <stefan.rueger@urclocks.com>
Date: Wed, 22 Oct 2025 22:40:42 +0200
Subject: [PATCH] Ensure memory segments stay within bounds

---
 src/fileio.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/fileio.c b/src/fileio.c
index e0754f6a..c0feeac5 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -1701,6 +1701,12 @@ int segment_normalise(const AVRMEM *mem, Segment *segp) {
     return -1;
   }
 
+  if(len > 0 && addr+len-1 >= maxsize) {
+    pmsg_error("segment length %d with starting address 0x%0*x reaches beyond memory end 0x%0*x\n",
+      segp->len, digits, addr, digits, maxsize-1);
+    return -1;
+  }
+
   segp->addr = addr;
   segp->len = len;