>From 03e529dd69d50c247a217b9b659659538dfa397a Mon Sep 17 00:00:00 2001
From: Collin Funk <collin.funk1@gmail.com>
Date: Thu, 27 Feb 2025 20:15:55 -0800
Subject: [PATCH] diff: fix allocation size computation that could cause bad
 writes

Reported by Nick Smallbone <nick@smallbone.se> in:
<https://lists.gnu.org/r/bug-diffutils/2025-02/msg00012.html>.

* src/io.c (find_and_hash_each_line): Fix size computation.
---
 src/io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/io.c b/src/io.c
index a62c529..adb4f50 100644
--- a/src/io.c
+++ b/src/io.c
@@ -1012,7 +1012,7 @@ find_and_hash_each_line (struct file_data *current)
 	  linbuf += linbuf_base;
 	  linbuf = xpalloc (linbuf, &n, 1, -1, sizeof *linbuf);
 	  linbuf -= linbuf_base;
-	  alloc_lines = n - linbuf_base;
+          alloc_lines = linbuf_base + n;
         }
       linbuf[line] = p;
 
-- 
2.48.1