Message-Id: <199907091809.SAA63418@out5.ibm.net>
From: "Mark E." <snowball3 AT bigfoot DOT com>
To: djgpp-workers AT delorie DOT com
Date: Fri, 9 Jul 1999 14:09:47 -0400
MIME-Version: 1.0
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Subject: patch for chkv2prg.c
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Reply-To: djgpp-workers AT delorie DOT com

Hello list,

_check_v2_prog will leak a file handle in the rare case when an 
executable is corrupt and the function was given a filename. One way 
to fix the problem is provided in the patch below.

*** src/libc/dos/process/chkv2prg.c.orig	Thu Oct  9 18:40:02 1997
--- src/libc/dos/process/chkv2prg.c	Fri Jul  9 13:59:34 1999
***************
*** 1,3 ****
--- 1,4 ----
+ /* Copyright (C) 1999 DJ Delorie, see COPYING.DJ for details */
  /* Copyright (C) 1997 DJ Delorie, see COPYING.DJ for details */
  #include <libc/stubs.h>
  #include <stdlib.h>
***************
*** 11,19 ****
  static _v2_prog_type type;
  static int type_initialized = 0;
  
  const _v2_prog_type *_check_v2_prog(const char *program, int pf)
  {
!   unsigned short header[5];
  
    if (type_initialized && type.stubinfo)
      free(type.stubinfo);
--- 12,23 ----
  static _v2_prog_type type;
  static int type_initialized = 0;
  
+ static
+ const _v2_prog_type *_check_v2_prog_internal (int pf);
+ 
  const _v2_prog_type *_check_v2_prog(const char *program, int pf)
  {
!   const _v2_prog_type *prog_type;
  
    if (type_initialized && type.stubinfo)
      free(type.stubinfo);
*************** const _v2_prog_type *_check_v2_prog(cons
*** 28,36 ****
        return &type;
    }
  
    lseek(pf, 0, SEEK_SET);
    if (read(pf, header, sizeof(header)) != sizeof(header))
!     return &type;
    if (header[0] == 0x010b || header[0] == 0x014c)
    {
      unsigned char firstbytes[1];
--- 32,54 ----
        return &type;
    }
  
+   prog_type = _check_v2_prog_internal(pf);
+ 
+   if (program)
+     close(pf);
+ 
+   if (prog_type)
+     type.valid = 1;
+   return &type;
+ }
+ 
+ static
+ const _v2_prog_type *_check_v2_prog_internal (int pf)
+ {
+   unsigned short header[5];
    lseek(pf, 0, SEEK_SET);
    if (read(pf, header, sizeof(header)) != sizeof(header))
!     return NULL;
    if (header[0] == 0x010b || header[0] == 0x014c)
    {
      unsigned char firstbytes[1];
*************** const _v2_prog_type *_check_v2_prog(cons
*** 64,72 ****
        coff_start += (long)header[1] - 512L;
      exe_start = (unsigned long)header[4]*16L;
      if (lseek(pf, exe_start, SEEK_SET) != exe_start)
!       return &type;
      if (read(pf, go32stub, 8) != 8)
!       return &type;
      go32stub[8] = 0;
      if (strcmp(go32stub, "go32stub") == 0)
      {
--- 82,90 ----
        coff_start += (long)header[1] - 512L;
      exe_start = (unsigned long)header[4]*16L;
      if (lseek(pf, exe_start, SEEK_SET) != exe_start)
!       return NULL;
      if (read(pf, go32stub, 8) != 8)
!       return NULL;
      go32stub[8] = 0;
      if (strcmp(go32stub, "go32stub") == 0)
      {
*************** const _v2_prog_type *_check_v2_prog(cons
*** 82,111 ****
        unsigned short coff_id;
        type.version.v.major = 1;
        if (lseek(pf, coff_start - 4, SEEK_SET) != coff_start-4)
!         return &type;
        if (read(pf, &stub_offset, 4) != 4)
!         return &type;
        if (read(pf, &coff_id, 2) != 2)
!         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)
!         return &type;
        if (read(pf, magic, 16) != 16)
!         return &type;
        if (memcmp(STUB_INFO_MAGIC, magic, 16) == 0)
        {
          if (read(pf, &struct_length, 4) != 4)
!           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)
!           return &type;
          type.has_stubinfo = 1;
        }
      }
--- 100,129 ----
        unsigned short coff_id;
        type.version.v.major = 1;
        if (lseek(pf, coff_start - 4, SEEK_SET) != coff_start-4)
!         return NULL;
        if (read(pf, &stub_offset, 4) != 4)
!         return NULL;
        if (read(pf, &coff_id, 2) != 2)
!         return NULL;
        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)
!         return NULL;
        if (read(pf, magic, 16) != 16)
!         return NULL;
        if (memcmp(STUB_INFO_MAGIC, magic, 16) == 0)
        {
          if (read(pf, &struct_length, 4) != 4)
!           return NULL;
          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)
!           return NULL;
          type.has_stubinfo = 1;
        }
      }
*************** const _v2_prog_type *_check_v2_prog(cons
*** 114,125 ****
    {
      type.exec_format = _V2_EXEC_FORMAT_UNIXSCRIPT;
    }
- 
-   if (program)
-     close(pf);
- 
-   type.valid = 1;
    return &type;
  }
- 
  
--- 132,137 ----

--- 
Mark Elbrecht, snowball3 AT bigfoot DOT com
http://snowball.frogspace.net/