Re: A Famous Security Bug

From	Michael S <already5chosen@yahoo.com>
Newsgroups	comp.lang.c
Subject	Re: A Famous Security Bug
Date	2024-03-25 18:51 +0200
Organization	A noiseless patient Spider
Message-ID	<20240325195118.0000333a@yahoo.com> (permalink)
References	(10 earlier) <utq0gh$i9hm$1@dont-email.me> <utqaak$kfuv$2@dont-email.me> <20240325141628.00006170@yahoo.com> <utrqgp$12v02$1@dont-email.me> <uts7e0$1686i$1@dont-email.me>

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On Mon, 25 Mar 2024 16:06:24 +0000
bart <bc@freeuk.com> wrote:

> On 25/03/2024 12:26, David Brown wrote:
> > On 25/03/2024 12:16, Michael S wrote:  
> >> On Sun, 24 Mar 2024 23:43:32 +0100
> >> David Brown <david.brown@hesbynett.no> wrote:  
> >>>
> >>> I could be  wrong here, of course.
> >>>  
> >>
> >> It seems, you are.
> >>  
> > 
> > It happens - and it was not unexpected here, as I said.  I don't
> > have all these compilers installed to test.
> > 
> > But it would be helpful if you had a /little/ more information.  If
> > you don't know why some compilers generate binaries that have
> > memory mapped at 0x400000, and others do not, fair enough.  I am
> > curious, but it's not at all important.
> >   
> 
> In the PE EXE format, the default image load base is specified in a 
> special header in the file:
> 
>    Magic:            20B
>    Link version:     1.0
>    Code size:        512 200
>    Idata size:       1024 400
>    Zdata size:       512
>    Entry point:      4096 1000 in data:0
>    Code base:        4096
>    Image base:       4194304 400000
>    Section align:    4096
> 
> By convention it is at 0x40'0000 (I've no idea why).
> 
> More recently, dynamic loading, regardless of what it says in the PE 
> header, has become popular with linkers. So, while there is still a 
> fixed value in the Image Base file, which might be 0x140000000, it
> gets loaded at some random address, usually in high memory above 2GB.
> 
> I don't know what's responsible for that, but presumably the OS must
> be in on the act.
> 
> To make this possible, both for loading above 2GB, and for loading at
> an address not known by the linker, the code inside the EXE must be 
> position-independent, and have relocation info for any absolute
> 64-bit static addresses. 32-bit static addresses won't work.
>

I don't understand why you say that EXE must be position-independent.
I never learned PE format in depth (and learned only absolute minimum of
elf, just enough to be able to load images in simple embedded
scenario), but my impression always was that PE EXE contains plenty of
relocation info for a loader, so it (loader) can modify (I think
professional argot uses the word 'fix') non-PIC at load time to run at
any chosen position.
Am I wrong about it?

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Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-20 18:54 +0000
  Re: A Famous Security Bug scott@slp53.sl.home (Scott Lurndal) - 2024-03-20 19:38 +0000
    Re: A Famous Security Bug Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-03-20 14:20 -0700
      Re: A Famous Security Bug Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-03-20 14:23 -0700
  Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-21 16:13 +0100
    Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-21 17:41 +0000
      Re: A Famous Security Bug "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-03-21 12:37 -0700
        Re: A Famous Security Bug scott@slp53.sl.home (Scott Lurndal) - 2024-03-21 20:21 +0000
          Re: A Famous Security Bug "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-03-21 14:31 -0700
            Re: A Famous Security Bug scott@slp53.sl.home (Scott Lurndal) - 2024-03-21 23:19 +0000
              Re: A Famous Security Bug "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-03-21 17:38 -0700
                Re: A Famous Security Bug "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-03-22 12:39 -0700
      Re: A Famous Security Bug Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-03-21 13:46 -0700
        Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-22 15:50 +0000
          Re: A Famous Security Bug Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-03-22 09:31 -0700
            Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-22 17:20 +0000
              Re: A Famous Security Bug James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-03-22 13:38 -0400
                Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-22 19:27 +0000
              Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-22 19:13 +0100
              Re: A Famous Security Bug Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-03-22 11:21 -0700
                Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-22 19:43 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-23 16:36 +0100
                Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-23 16:07 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-23 18:58 +0100
                Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-24 01:23 +0000
                Re: A Famous Security Bug James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-03-23 12:51 -0400
                Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-24 05:50 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-24 14:21 +0100
                Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-24 16:02 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-24 17:27 +0100
                Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-27 21:06 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-28 19:07 +0100
                Re: A Famous Security Bug "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-03-24 12:45 -0700
          Re: A Famous Security Bug James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-03-22 13:05 -0400
          Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-22 18:42 +0100
            Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-22 18:55 +0000
              Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-22 21:26 +0100
        Re: A Famous Security Bug James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-03-22 12:35 -0400
          Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-22 17:28 +0000
            Re: A Famous Security Bug James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-03-22 13:38 -0400
      Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-22 13:51 +0100
  Re: A Famous Security Bug Anton Shepelev <anton.txt@gmail.moc> - 2024-03-21 21:13 +0300
    Re: A Famous Security Bug Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-03-21 12:42 -0700
    Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-21 20:21 +0000
      Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-22 14:38 +0100
        Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-22 15:33 +0000
          Re: A Famous Security Bug James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-03-22 13:15 -0400
          Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-22 18:50 +0100
            Re: A Famous Security Bug Richard Kettlewell <invalid@invalid.invalid> - 2024-03-23 09:20 +0000
              Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-23 16:06 +0000
              Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-23 17:08 +0100
                Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-23 16:56 +0000
              Re: A Famous Security Bug Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-24 09:45 -0700
                Re: A Famous Security Bug Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-24 17:53 +0000
                Re: A Famous Security Bug Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-04-17 12:10 -0700
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-04-18 10:20 +0200
                Re: A Famous Security Bug Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-04-18 14:26 -0700
      Re: A Famous Security Bug Anton Shepelev <anton.txt@g{oogle}mail.com> - 2024-03-28 12:23 +0300
        Re: A Famous Security Bug scott@slp53.sl.home (Scott Lurndal) - 2024-03-28 14:12 +0000
    Re: A Famous Security Bug Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-22 07:50 -0700
    Re: A Famous Security Bug James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-03-22 13:14 -0400
      Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-22 21:41 +0000
        Re: A Famous Security Bug Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-03-22 16:30 -0700
          Re: A Famous Security Bug Kaz Kylheku <433-929-6894@kylheku.com> - 2024-03-23 00:09 +0000
            Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-23 17:25 +0100
              Re: A Famous Security Bug scott@slp53.sl.home (Scott Lurndal) - 2024-03-23 16:51 +0000
              Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-23 19:58 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-24 14:42 +0100
        Re: A Famous Security Bug James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-03-23 03:26 -0400
          Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-23 11:26 +0000
            Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-23 17:51 +0100
              Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-23 21:21 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-24 15:52 +0100
                Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-24 19:56 +0000
                Re: A Famous Security Bug Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-03-24 13:49 -0700
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-24 23:38 +0100
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-25 01:42 +0300
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-25 09:37 +0100
                Re: A Famous Security Bug Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-03-25 08:54 -0700
                Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-24 23:07 +0000
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-25 01:39 +0200
                Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-25 02:12 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-25 09:58 +0100
                Re: A Famous Security Bug Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-03-25 13:26 +0000
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-25 15:43 +0200
                Re: A Famous Security Bug scott@slp53.sl.home (Scott Lurndal) - 2024-03-25 17:21 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-25 09:53 +0100
                Re: A Famous Security Bug scott@slp53.sl.home (Scott Lurndal) - 2024-03-25 17:24 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-24 23:43 +0100
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-25 13:16 +0200
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-25 13:26 +0100
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-25 15:11 +0200
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-25 16:30 +0100
                Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-25 16:39 +0000
                Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-25 16:06 +0000
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-25 18:51 +0200
                Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-25 18:10 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-25 21:01 +0100
                Re: A Famous Security Bug scott@slp53.sl.home (Scott Lurndal) - 2024-03-25 20:28 +0000
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-25 23:05 +0200
                Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-25 21:25 +0000
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-26 01:31 +0200
                Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-26 00:34 +0000
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-25 19:07 +0100
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-24 18:53 +0300
                Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-24 18:58 +0000
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-25 13:04 +0200
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-25 13:24 +0200
                Re: A Famous Security Bug David Brown <david.brown@hesbynett.no> - 2024-03-25 16:17 +0100
                Re: A Famous Security Bug James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-03-28 06:14 -0400
            Re: A Famous Security Bug Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-03-23 11:44 -0700
            Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-24 17:22 +0300
            Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-24 17:26 +0300
              Re: A Famous Security Bug bart <bc@freeuk.com> - 2024-03-24 19:12 +0000
                Re: A Famous Security Bug Michael S <already5chosen@yahoo.com> - 2024-03-24 22:33 +0300
            Re: A Famous Security Bug James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-03-28 05:52 -0400

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