From 9d8d6804a414a29c2b452ac8d1ef5940dec60b80 Mon Sep 17 00:00:00 2001
From: Jakob Flierl <jakob.flierl@gmail.com>
Date: Sat, 5 Jul 2025 20:08:54 +0200
Subject: [PATCH] closes #397; Fix a buffer overflow bug in the ringbuffer
 code.

---
 src/libraries/runtime/include/runtime/ring.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libraries/runtime/include/runtime/ring.h b/src/libraries/runtime/include/runtime/ring.h
index c0e076b2e..939e58983 100644
--- a/src/libraries/runtime/include/runtime/ring.h
+++ b/src/libraries/runtime/include/runtime/ring.h
@@ -1120,7 +1120,7 @@ static inline ringsize_t stream_write(ringbuffer_t *ring,
     memcpy (&(ring->buf[t->tail]), src, n1);
 
     if (n2) {
-	memcpy (&(ring->buf[t->tail + n1]), src + n1, n2);
+	memcpy(ring->buf, src + n1, n2);
 	rtapi_smp_wmb();
 	rtapi_store_u32(&t->tail, (t->tail + n1 + n2) & h->size_mask);
     } else {