c++ program reboots system.

c++ program reboots system.

[Richard B. Johnson]

I didn't save the address of the person who reported the reboot
error...
This c++ code was reported to reboot a machine.

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <iterator>
using namespace std;
int main(int argc, char** argv)
{
    string raw_filename = "input.out";
    ifstream raw_file(raw_filename.c_str());
    vector<long> data;
    copy(istream_iterator<long>(raw_file),istream_iterator<long>(),back_inserter(data));
    data.erase(data.begin());
    return 0;
}
Script started on Mon May 13 07:51:12 2002
# gdb xxx
GDB is free software and you are welcome to distribute copies of it
 under certain conditions; type "show copying" to see the conditions.
There is absolutely no warranty for GDB; type "show warranty" for details.
GDB 4.15 (i586-unknown-linux), Copyright 1995 Free Software Foundation, Inc...
(gdb) run
Starting program: /root/xxx 

Program received signal SIGSEGV, Segmentation fault.
ostream::flush (this=0x8c224) at iostream.cc:864
864	    if (_strbuf->sync())
(gdb) quit
The program is running.  Quit anyway (and kill it)? (y or n) y
# exit
exit
Script done on Mon May 13 07:51:49 2002

On Linux 2.4.18, the program just seg-faults (as it should).
On the version you are using, you should write a 'C' program
that does lseek() beyond EOF. There could be a bug there, but
otherwise I can't tell from the program presented.


Cheers,
Dick Johnson

Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).

                 Windows-2000/Professional isn't.

Re: c++ program reboots system.

[rpm]

> }
> Script started on Mon May 13 07:51:12 2002
> # gdb xxx
> GDB is free software and you are welcome to distribute copies of it
>  under certain conditions; type "show copying" to see the conditions.
> There is absolutely no warranty for GDB; type "show warranty" for details.
> GDB 4.15 (i586-unknown-linux), Copyright 1995 Free Software Foundation,
> Inc... (gdb) run
> Starting program: /root/xxx
>
> Program received signal SIGSEGV, Segmentation fault.
> ostream::flush (this=0x8c224) at iostream.cc:864
> 864	    if (_strbuf->sync())
> (gdb) quit
> The program is running.  Quit anyway (and kill it)? (y or n) y
> # exit
> exit
> Script done on Mon May 13 07:51:49 2002
>
> On Linux 2.4.18, the program just seg-faults (as it should).
> On the version you are using, you should write a 'C' program
> that does lseek() beyond EOF. There could be a bug there, but
> otherwise I can't tell from the program presented.

I executed the same C++ code on iPAQ , on the 2.4.7 kernel and it works fine !
no seg faults no reboots,
I also tried the C program you suggested , but that too works fine,  no 
reboots no seg faults!   :(

rpm
 

Re: c++ program reboots system.

[Richard B. Johnson]

On Mon, 13 May 2002, rpm wrote:

> > }
> > Script started on Mon May 13 07:51:12 2002
> > # gdb xxx
> > GDB is free software and you are welcome to distribute copies of it
> >  under certain conditions; type "show copying" to see the conditions.
> > There is absolutely no warranty for GDB; type "show warranty" for details.
> > GDB 4.15 (i586-unknown-linux), Copyright 1995 Free Software Foundation,
> > Inc... (gdb) run
> > Starting program: /root/xxx
> >
> > Program received signal SIGSEGV, Segmentation fault.
> > ostream::flush (this=0x8c224) at iostream.cc:864
> > 864	    if (_strbuf->sync())
> > (gdb) quit
> > The program is running.  Quit anyway (and kill it)? (y or n) y
> > # exit
> > exit
> > Script done on Mon May 13 07:51:49 2002
> >
> > On Linux 2.4.18, the program just seg-faults (as it should).
> > On the version you are using, you should write a 'C' program
> > that does lseek() beyond EOF. There could be a bug there, but
> > otherwise I can't tell from the program presented.
> 
> I executed the same C++ code on iPAQ , on the 2.4.7 kernel and it works fine !
> no seg faults no reboots,
> I also tried the C program you suggested , but that too works fine,  no 
> reboots no seg faults!   :(
> 

This is the file I used...
`cp /dev/zero input.out` ^C after a second.

-rw-------   1 root     root     117010432 May 13 07:47 input.out

It seg-faults every time..


Cheers,
Dick Johnson

Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips).

                 Windows-2000/Professional isn't.