Subject: kern/8925: A fork bomb trigers a kernel panic
To: None <gnats-bugs@gnats.netbsd.org>
From: None <p99dreyf@criens.u-psud.fr>
List: netbsd-bugs
Date: 11/30/1999 14:24:40
>Number:         8925
>Category:       kern
>Synopsis:       A fork bomb trigers a kernel panic
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    kern-bug-people (Kernel Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Nov 30 14:24:01 1999
>Last-Modified:
>Originator:     Emmanuel Dreyfus
>Organization:
None
>Release:        NetBSD-1.4.1/mac68k
>Environment:
NetBSD gizmo 1.4.1 NetBSD 1.4.1 (DEBUG) #2: Wed Oct 27 09:23:37 CEST 1999     ro
ot@gizmo:/usr/src/sys/arch/mac68k/compile/DEBUG mac68k


>Description:
I was trying to reproduce the processes stuck in uvn_get problem 
(see kern/8679). Launching a fork bomb as any normal user does nothing 
but increasing the load. That's normal. When I launched the fork bomb
as root, I expected the system getting uncontrolable, but not a kernel
crash. Here is the crash message:
panic: pmap_page_protect: bad mapping
Stopped in pagedaemon at _Debugger+0x6: unlk a6

I have a crash dump, but since mac68k crash dump seems to be broken as 
well, I assume it will be of no interest.

>How-To-Repeat:
#include <unistd.h>  /* Run me as root */
int main (int argc, char* argv[]) {
        pid_t   dontcare;
        while (1) {dontcare=fork();}
}
>Fix:
Sorry... :o/
>Audit-Trail:
>Unformatted: