How to take down a system to the point of requiring a newfs with one line of C (userland)

Kurt Buff kurt.buff at gmail.com
Mon Feb 18 13:42:46 UTC 2008


Patient: Doctor, it hurts when I do this!

Doctor: Don't do that...

On Feb 18, 2008 1:23 PM, Dag-Erling Smørgrav <des at des.no> wrote:
> Jim Bryant <freebsd at electron-tube.net> writes:
> > #include <stdio.h>
> > #include <stdlib.h>
> >
> > int main(int argc, char **argv) { int i; char buf[1024]; bzero(buf, 1024); for(i = 0; i < 10000; i++) { sprintf(buf, "touch %s%05d\n", argv[1], i); system((const char *)buf);} return(0);}
>
> Subject should be "how to take down a system [...] with three lines of
> badly written C, provided you have root privileges already and are too
> lazy to just dd if=/dev/zero of=/dev/ad0s1 count=100", which would
> accomplish the job much faster.
>
> Purely in the interest of showing off, here is my version.  It is 81
> bytes shorter than yours, it is valid C99 with POSIX extensions (yours
> is not), and it produces 11,450 files in about 0.2% of the time yours
> takes to produce 10,000.
>
> #include <unistd.h>
> #define b(i,v) for(int v=48;v<127;++v){f[i]=v;
> #define a(i) b(i,v##i)
> int main(void){char f[5]={'/'};a(1)a(2)a(3)truncate(f,0);}}}}
>
> DES
> --
> Dag-Erling Smørgrav - des at des.no
>
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