Sender: root AT delorie DOT com
Message-ID: <37EF5E4E.F552690E@inti.gov.ar>
Date: Mon, 27 Sep 1999 09:08:46 -0300
From: salvador <salvador AT inti DOT gov DOT ar>
Organization: INTI
X-Mailer: Mozilla 4.6 [en] (X11; I; Linux 2.0.38 i686)
X-Accept-Language: es-AR, en, es
MIME-Version: 1.0
To: djgpp-workers AT delorie DOT com
Subject: Bug in 2.02, don't know about 2.03
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Reply-To: djgpp-workers AT delorie DOT com

Hi All!

  I found a very annoying bug in 2.02, I couldn't check 2.03 sorry.
  The system/spawn family of functions opens the external file if it is a
.exe to check if that's a djgpp program. The bug if that chkv2prg doesn't
close the file if the test fails!
  It produce a couple of nasty side effects:

1) Programs spawned by djgpp programs becomes read-only while the djgpp
program stills running (at least under W9x).
2) We leak file handlers.

  Just in case it wasn't fixed I included a prototype patch, the only purpose
is just to show the points I think must be fixed.


SET

P.S. If you wonder how I found it: one user of my editor is using the editor
as Turbo Pascal 7 IDE replacement ;-)

--- chkv2prg.c~ Thu Oct  9 22:40:02 1997
+++ chkv2prg.c  Sat Sep 25 14:34:38 1999
@@ -30,7 +30,10 @@

   lseek(pf, 0, SEEK_SET);
   if (read(pf, header, sizeof(header)) != sizeof(header))
+  {
+    close(pf);
     return &type;
+  }
   if (header[0] == 0x010b || header[0] == 0x014c)
   {
     unsigned char firstbytes[1];
@@ -64,9 +67,15 @@
       coff_start += (long)header[1] - 512L;
     exe_start = (unsigned long)header[4]*16L;
     if (lseek(pf, exe_start, SEEK_SET) != exe_start)
+    {
+      close(pf);
       return &type;
+    }
     if (read(pf, go32stub, 8) != 8)
+    {
+      close(pf);
       return &type;
+    }
     go32stub[8] = 0;
     if (strcmp(go32stub, "go32stub") == 0)
     {
@@ -82,30 +91,51 @@
       unsigned short coff_id;
       type.version.v.major = 1;
       if (lseek(pf, coff_start - 4, SEEK_SET) != coff_start-4)
+      {
+        close(pf);
         return &type;
+      }
       if (read(pf, &stub_offset, 4) != 4)
+      {
+        close(pf);
         return &type;
+      }
       if (read(pf, &coff_id, 2) != 2)
+      {
+        close(pf);
         return &type;
+      }
       if (coff_id == 0x010b || coff_id == 0x014c)
       {
         type.object_format = _V2_OBJECT_FORMAT_COFF;
         type.exec_format = _V2_EXEC_FORMAT_STUBCOFF;
       }
       if (lseek(pf, stub_offset, 0) != stub_offset)
+      {
+        close(pf);
         return &type;
+      }
       if (read(pf, magic, 16) != 16)
+      {
+        close(pf);
         return &type;
+      }
       if (memcmp(STUB_INFO_MAGIC, magic, 16) == 0)
       {
         if (read(pf, &struct_length, 4) != 4)
+        {
+          close(pf);
           return &type;
+        }
         type.stubinfo = (_v1_stubinfo *)malloc(struct_length);
         memcpy(type.stubinfo->magic, magic, 16);
         type.stubinfo->struct_length = struct_length;
         if (read(pf, type.stubinfo->go32, struct_length - 20)
             != struct_length - 20)
+        {
+          close(pf);
           return &type;
+        }
         type.has_stubinfo = 1;
       }
     }

--
Salvador Eduardo Tropea (SET). (Electronics Engineer)
Visit my home page: http://welcome.to/SetSoft or
http://www.geocities.com/SiliconValley/Vista/6552/
Alternative e-mail: set-soft AT usa DOT net set AT computer DOT org
                    set AT ieee DOT org set-soft AT bigfoot DOT com
Address: Curapaligue 2124, Caseros, 3 de Febrero
Buenos Aires, (1678), ARGENTINA Phone: +(5411) 4759 0013