From 09d7f7fce3231513d5a970f6029f3335449e8be6 Mon Sep 17 00:00:00 2001
From: giraffedata <giraffedata@9d0c8265-081b-0410-96cb-a4ca84ce46f8>
Date: Sat, 19 Aug 2023 18:02:53 +0000
Subject: Add computable size check for maxval

git-svn-id: http://svn.code.sf.net/p/netpbm/code/trunk@4602 9d0c8265-081b-0410-96cb-a4ca84ce46f8
---
 lib/libpgm1.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

(limited to 'lib/libpgm1.c')

diff --git a/lib/libpgm1.c b/lib/libpgm1.c
index 9c089cc0..6feb1c8b 100644
--- a/lib/libpgm1.c
+++ b/lib/libpgm1.c
@@ -115,6 +115,28 @@ validateComputableSize(unsigned int const cols,
 
 
 
+static void
+validateComputableMaxval(gray const maxval) {
+/*----------------------------------------------------------------------------
+  This is similar to validateComputableSize, but for the maxval.
+-----------------------------------------------------------------------------*/
+    /* Code sometimes allocates an array indexed by sample values and
+       represents the size of that array as an INT.  (UNSIGNED INT would be
+       more proper, but there's no need to be that permissive).
+
+       Code also sometimes iterates through sample values and quits when the
+       value is greater than the maxval.
+    */
+
+    if (maxval == 0)
+        pm_error("Maxval is zero.  Must be at least one.");
+
+    if (maxval > INT_MAX-1)
+        pm_error("Maxval (%u) is too large to be processed", maxval);
+}
+
+
+
 void
 pgm_readpgminit(FILE * const fileP,
                 int *  const colsP,
@@ -172,6 +194,8 @@ pgm_readpgminit(FILE * const fileP,
                  realFormat);
     }
     validateComputableSize(*colsP, *rowsP);
+
+    validateComputableMaxval(*maxvalP);
 }
 
 
-- 
cgit 1.4.1