diff -pruN sed-4.8_orig/sed/regexp.c sed-4.8_mod/sed/regexp.c
--- sed-4.8_orig/sed/regexp.c	2020-01-02 04:38:19.000000000 +0900
+++ sed-4.8_mod/sed/regexp.c	2021-11-13 13:30:06.288317776 +0900
@@ -30,6 +30,12 @@
 # define N_(String) (String)
 #endif
 
+#ifdef _REGEX_LARGE_OFFSETS
+# define REGOFF_MAX SSIZE_MAX
+#else
+# define REGOFF_MAX INT_MAX
+#endif
+
 extern bool use_extended_syntax_p;
 
 static const char errors[] =
@@ -176,7 +182,7 @@ match_regex (struct regex *regex, char *
             size_t buf_start_offset, struct re_registers *regarray,
             int regsize)
 {
-  int ret;
+  regoff_t ret;
   static struct regex *regex_last;
 
   /* printf ("Matching from %d/%d\n", buf_start_offset, buflen); */
@@ -191,9 +197,10 @@ match_regex (struct regex *regex, char *
   else
     regex_last = regex;
 
-  /* gnulib's re_search uses signed-int as length */
-  if (buflen >= INT_MAX)
-    panic (_("regex input buffer length larger than INT_MAX"));
+  /* gnulib's re_search uses regoff_t as length */
+  if (buflen > REGOFF_MAX)
+    panic (_("regex input buffer length larger than limit(%zd)"),
+           (ssize_t)REGOFF_MAX);
 
   if (regex->pattern.no_sub && regsize)
     {
@@ -359,6 +366,9 @@ match_regex (struct regex *regex, char *
                      buflen - buf_start_offset,
                      regsize ? regarray : NULL);
 
+  if (ret < -1)
+    panic ("internal error in gnulib's re_search. ret = %zd", (ssize_t)ret);
+
   return (ret > -1);
 }