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#include <AK/String.h>
#include <Kernel/Syscall.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
static void print_usage_and_exit()
{
printf("usage: crash -[sdiamfMFTt]\n");
exit(0);
}
#pragma GCC optimize("O0")
int main(int argc, char** argv)
{
enum Mode {
SegmentationViolation,
DivisionByZero,
IllegalInstruction,
Abort,
WriteToUninitializedMallocMemory,
WriteToFreedMemory,
ReadFromUninitializedMallocMemory,
ReadFromFreedMemory,
WriteToReadonlyMemory,
InvalidStackPointerOnSyscall,
InvalidStackPointerOnPageFault,
SyscallFromWritableMemory,
};
Mode mode = SegmentationViolation;
if (argc != 2)
print_usage_and_exit();
if (String(argv[1]) == "-s")
mode = SegmentationViolation;
else if (String(argv[1]) == "-d")
mode = DivisionByZero;
else if (String(argv[1]) == "-i")
mode = IllegalInstruction;
else if (String(argv[1]) == "-a")
mode = Abort;
else if (String(argv[1]) == "-m")
mode = ReadFromUninitializedMallocMemory;
else if (String(argv[1]) == "-f")
mode = ReadFromFreedMemory;
else if (String(argv[1]) == "-M")
mode = WriteToUninitializedMallocMemory;
else if (String(argv[1]) == "-F")
mode = WriteToFreedMemory;
else if (String(argv[1]) == "-r")
mode = WriteToReadonlyMemory;
else if (String(argv[1]) == "-T")
mode = InvalidStackPointerOnSyscall;
else if (String(argv[1]) == "-t")
mode = InvalidStackPointerOnPageFault;
else if (String(argv[1]) == "-S")
mode = SyscallFromWritableMemory;
else
print_usage_and_exit();
if (mode == SegmentationViolation) {
volatile int* crashme = nullptr;
*crashme = 0xbeef;
ASSERT_NOT_REACHED();
}
if (mode == DivisionByZero) {
volatile int lala = 10;
volatile int zero = 0;
volatile int test = lala / zero;
(void)test;
ASSERT_NOT_REACHED();
}
if (mode == IllegalInstruction) {
asm volatile("ud2");
ASSERT_NOT_REACHED();
}
if (mode == Abort) {
abort();
ASSERT_NOT_REACHED();
}
if (mode == ReadFromUninitializedMallocMemory) {
auto* uninitialized_memory = (volatile u32**)malloc(1024);
volatile auto x = uninitialized_memory[0][0];
(void)x;
ASSERT_NOT_REACHED();
}
if (mode == ReadFromFreedMemory) {
auto* uninitialized_memory = (volatile u32**)malloc(1024);
free(uninitialized_memory);
volatile auto x = uninitialized_memory[4][0];
(void)x;
ASSERT_NOT_REACHED();
}
if (mode == WriteToUninitializedMallocMemory) {
auto* uninitialized_memory = (volatile u32**)malloc(1024);
uninitialized_memory[4][0] = 1;
ASSERT_NOT_REACHED();
}
if (mode == WriteToFreedMemory) {
auto* uninitialized_memory = (volatile u32**)malloc(1024);
free(uninitialized_memory);
uninitialized_memory[4][0] = 1;
ASSERT_NOT_REACHED();
}
if (mode == WriteToReadonlyMemory) {
auto* ptr = (u8*)mmap(nullptr, 4096, PROT_READ | PROT_WRITE, MAP_ANON, 0, 0);
ASSERT(ptr != MAP_FAILED);
*ptr = 'x'; // This should work fine.
int rc = mprotect(ptr, 4096, PROT_READ);
ASSERT(rc == 0);
ASSERT(*ptr == 'x');
*ptr = 'y'; // This should crash!
}
if (mode == InvalidStackPointerOnSyscall) {
u8* makeshift_stack = (u8*)mmap(nullptr, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_STACK, 0, 0);
if (!makeshift_stack) {
perror("mmap");
return 1;
}
u8* makeshift_esp = makeshift_stack + 2048;
asm volatile("mov %%eax, %%esp" :: "a"(makeshift_esp));
getuid();
dbgprintf("Survived syscall with MAP_STACK stack\n");
u8* bad_stack = (u8*)mmap(nullptr, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
if (!bad_stack) {
perror("mmap");
return 1;
}
u8* bad_esp = bad_stack + 2048;
asm volatile("mov %%eax, %%esp" :: "a"(bad_esp));
getuid();
ASSERT_NOT_REACHED();
}
if (mode == InvalidStackPointerOnPageFault) {
u8* bad_stack = (u8*)mmap(nullptr, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
if (!bad_stack) {
perror("mmap");
return 1;
}
u8* bad_esp = bad_stack + 2048;
asm volatile("mov %%eax, %%esp" :: "a"(bad_esp));
asm volatile("pushl $0");
ASSERT_NOT_REACHED();
}
if (mode == SyscallFromWritableMemory) {
u8 buffer[] = { 0xb8, Syscall::SC_getuid, 0, 0, 0, 0xcd, 0x82 };
((void(*)())buffer)();
}
ASSERT_NOT_REACHED();
return 0;
}
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