Origin:
https://github.com/TeX-Live/texlive-source/commit/33b330bc48ed2df69daf80a81be3cde8bf794816
https://tug.org/pipermail/tex-live/2023-August/049402.html

From 33b330bc48ed2df69daf80a81be3cde8bf794816 Mon Sep 17 00:00:00 2001
From: Karl Berry <[email protected]>
Date: Sat, 26 Aug 2023 17:50:10 +0000
Subject: [PATCH] guard against corrupt pfb in dup tests, pdftex r910

git-svn-id: svn://tug.org/texlive/trunk/Build/source@68069 c570f23f-e606-0410-a88d-b1316a301751
---
 texlive-20210325-source/texk/web2c/pdftexdir/writet1.c | 15 ++++++++++++---
 1 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/texlive-20210325-source/texk/web2c/pdftexdir/writet1.c b/texlive-20210325-source/texk/web2c/pdftexdir/writet1.c
index 0444d46be0..f2a8386cab 100644
--- a/texlive-20210325-source/texk/web2c/pdftexdir/writet1.c
+++ b/texlive-20210325-source/texk/web2c/pdftexdir/writet1.c
@@ -841,7 +841,10 @@ static char **t1_builtin_enc(void)
                 *t1_buf_array == '/' && valid_code(i)) {
                 if (strcmp(t1_buf_array + 1, notdef) != 0)
                     glyph_names[i] = xstrdup(t1_buf_array + 1);
-                p = strstr(p, " put") + strlen(" put");
+                p = strstr(p, " put");
+                if (!p)
+                    pdftex_fail("invalid pfb, no put found in dup");
+                p += strlen(" put");
                 skip(p, ' ');
             }
             /*
@@ -850,7 +853,10 @@ static char **t1_builtin_enc(void)
             else if (sscanf(p, "dup dup %i exch %i get put", &b, &a) == 2
                      && valid_code(a) && valid_code(b)) {
                 copy_glyph_names(glyph_names, a, b);
-                p = strstr(p, " get put") + strlen(" get put");
+                p = strstr(p, " get put");
+                if (!p)
+                    pdftex_fail("invalid pfb, no get put found in dup dup");
+                p += strlen(" get put");
                 skip(p, ' ');
             }
             /*
@@ -861,7 +867,10 @@ static char **t1_builtin_enc(void)
                      && valid_code(a) && valid_code(b) && valid_code(c)) {
                 for (i = 0; i < c; i++)
                     copy_glyph_names(glyph_names, a + i, b + i);
-                p = strstr(p, " putinterval") + strlen(" putinterval");
+                p = strstr(p, " putinterval");
+                if (!p)
+                   pdftex_fail("invalid pfb, no putinterval found in dup dup");
+                p += strlen(" putinterval");
                 skip(p, ' ');
             }
             /*