1 #include <assert.h>
2 #include <errno.h>
3 #include <pthread.h>
4 #include <sched.h>
5 #include <signal.h>
6 #include <stdio.h>
7 #include <stdlib.h>
8 #include <string.h>
9 #include <sys/cdefs.h>
10 #include <sys/mman.h>
11 #include <sys/ptrace.h>
12 #include <sys/socket.h>
13 #include <sys/wait.h>
14 #include <unistd.h>
15
16 #include <cutils/sockets.h>
17 #include <log/log.h>
18
19 #ifndef __unused
20 #define __unused __attribute__((__unused__))
21 #endif
22
23 extern const char* __progname;
24
25 void crash1(void);
26 void crashnostack(void);
27 static int do_action(const char* arg);
28
maybe_abort()29 static void maybe_abort() {
30 if (time(0) != 42) {
31 abort();
32 }
33 }
34
35 static char* smash_stack_dummy_buf;
smash_stack_dummy_function(volatile int * plen)36 __attribute__ ((noinline)) static void smash_stack_dummy_function(volatile int* plen) {
37 smash_stack_dummy_buf[*plen] = 0;
38 }
39
40 // This must be marked with "__attribute__ ((noinline))", to ensure the
41 // compiler generates the proper stack guards around this function.
42 // Assign local array address to global variable to force stack guards.
43 // Use another noinline function to corrupt the stack.
smash_stack(volatile int * plen)44 __attribute__ ((noinline)) static int smash_stack(volatile int* plen) {
45 printf("crasher: deliberately corrupting stack...\n");
46
47 char buf[128];
48 smash_stack_dummy_buf = buf;
49 // This should corrupt stack guards and make process abort.
50 smash_stack_dummy_function(plen);
51 return 0;
52 }
53
54 #if defined(__clang__)
55 #pragma clang diagnostic push
56 #pragma clang diagnostic ignored "-Winfinite-recursion"
57 #endif
58
59 static void* global = 0; // So GCC doesn't optimize the tail recursion out of overflow_stack.
60
overflow_stack(void * p)61 __attribute__((noinline)) static void overflow_stack(void* p) {
62 void* buf[1];
63 buf[0] = p;
64 global = buf;
65 overflow_stack(&buf);
66 }
67
68 #if defined(__clang__)
69 #pragma clang diagnostic pop
70 #endif
71
noisy(void * x)72 static void *noisy(void *x)
73 {
74 char c = (uintptr_t) x;
75 for(;;) {
76 usleep(250*1000);
77 write(2, &c, 1);
78 if(c == 'C') *((volatile unsigned*) 0) = 42;
79 }
80 return NULL;
81 }
82
ctest()83 static int ctest()
84 {
85 pthread_t thr;
86 pthread_attr_t attr;
87 pthread_attr_init(&attr);
88 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
89 pthread_create(&thr, &attr, noisy, (void*) 'A');
90 pthread_create(&thr, &attr, noisy, (void*) 'B');
91 pthread_create(&thr, &attr, noisy, (void*) 'C');
92 for(;;) ;
93 return 0;
94 }
95
thread_callback(void * raw_arg)96 static void* thread_callback(void* raw_arg)
97 {
98 return (void*) (uintptr_t) do_action((const char*) raw_arg);
99 }
100
do_action_on_thread(const char * arg)101 static int do_action_on_thread(const char* arg)
102 {
103 pthread_t t;
104 pthread_create(&t, NULL, thread_callback, (void*) arg);
105 void* result = NULL;
106 pthread_join(t, &result);
107 return (int) (uintptr_t) result;
108 }
109
crash3(int a)110 __attribute__((noinline)) static int crash3(int a) {
111 *((int*) 0xdead) = a;
112 return a*4;
113 }
114
crash2(int a)115 __attribute__((noinline)) static int crash2(int a) {
116 a = crash3(a) + 2;
117 return a*3;
118 }
119
crash(int a)120 __attribute__((noinline)) static int crash(int a) {
121 a = crash2(a) + 1;
122 return a*2;
123 }
124
abuse_heap()125 static void abuse_heap() {
126 char buf[16];
127 free((void*) buf); // GCC is smart enough to warn about this, but we're doing it deliberately.
128 }
129
sigsegv_non_null()130 static void sigsegv_non_null() {
131 int* a = (int *)(&do_action);
132 *a = 42;
133 }
134
do_action(const char * arg)135 static int do_action(const char* arg)
136 {
137 fprintf(stderr,"crasher: init pid=%d tid=%d\n", getpid(), gettid());
138
139 if (!strncmp(arg, "thread-", strlen("thread-"))) {
140 return do_action_on_thread(arg + strlen("thread-"));
141 } else if (!strcmp(arg, "SIGSEGV-non-null")) {
142 sigsegv_non_null();
143 } else if (!strcmp(arg, "smash-stack")) {
144 volatile int len = 128;
145 return smash_stack(&len);
146 } else if (!strcmp(arg, "stack-overflow")) {
147 overflow_stack(NULL);
148 } else if (!strcmp(arg, "nostack")) {
149 crashnostack();
150 } else if (!strcmp(arg, "ctest")) {
151 return ctest();
152 } else if (!strcmp(arg, "exit")) {
153 exit(1);
154 } else if (!strcmp(arg, "crash") || !strcmp(arg, "SIGSEGV")) {
155 return crash(42);
156 } else if (!strcmp(arg, "abort")) {
157 maybe_abort();
158 } else if (!strcmp(arg, "assert")) {
159 __assert("some_file.c", 123, "false");
160 } else if (!strcmp(arg, "assert2")) {
161 __assert2("some_file.c", 123, "some_function", "false");
162 } else if (!strcmp(arg, "LOG_ALWAYS_FATAL")) {
163 LOG_ALWAYS_FATAL("hello %s", "world");
164 } else if (!strcmp(arg, "LOG_ALWAYS_FATAL_IF")) {
165 LOG_ALWAYS_FATAL_IF(true, "hello %s", "world");
166 } else if (!strcmp(arg, "SIGFPE")) {
167 raise(SIGFPE);
168 return EXIT_SUCCESS;
169 } else if (!strcmp(arg, "SIGTRAP")) {
170 raise(SIGTRAP);
171 return EXIT_SUCCESS;
172 } else if (!strcmp(arg, "heap-usage")) {
173 abuse_heap();
174 } else if (!strcmp(arg, "SIGSEGV-unmapped")) {
175 char* map = mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
176 munmap(map, sizeof(int));
177 map[0] = '8';
178 }
179
180 fprintf(stderr, "%s OP\n", __progname);
181 fprintf(stderr, "where OP is:\n");
182 fprintf(stderr, " smash-stack overwrite a stack-guard canary\n");
183 fprintf(stderr, " stack-overflow recurse until the stack overflows\n");
184 fprintf(stderr, " heap-corruption cause a libc abort by corrupting the heap\n");
185 fprintf(stderr, " heap-usage cause a libc abort by abusing a heap function\n");
186 fprintf(stderr, " nostack crash with a NULL stack pointer\n");
187 fprintf(stderr, " ctest (obsoleted by thread-crash?)\n");
188 fprintf(stderr, " exit call exit(1)\n");
189 fprintf(stderr, " abort call abort()\n");
190 fprintf(stderr, " assert call assert() without a function\n");
191 fprintf(stderr, " assert2 call assert() with a function\n");
192 fprintf(stderr, " LOG_ALWAYS_FATAL call LOG_ALWAYS_FATAL\n");
193 fprintf(stderr, " LOG_ALWAYS_FATAL_IF call LOG_ALWAYS_FATAL\n");
194 fprintf(stderr, " SIGFPE cause a SIGFPE\n");
195 fprintf(stderr, " SIGSEGV cause a SIGSEGV at address 0x0 (synonym: crash)\n");
196 fprintf(stderr, " SIGSEGV-non-null cause a SIGSEGV at a non-zero address\n");
197 fprintf(stderr, " SIGSEGV-unmapped mmap/munmap a region of memory and then attempt to access it\n");
198 fprintf(stderr, " SIGTRAP cause a SIGTRAP\n");
199 fprintf(stderr, "prefix any of the above with 'thread-' to not run\n");
200 fprintf(stderr, "on the process' main thread.\n");
201 return EXIT_SUCCESS;
202 }
203
main(int argc,char ** argv)204 int main(int argc, char **argv)
205 {
206 fprintf(stderr,"crasher: built at " __TIME__ "!@\n");
207
208 if(argc > 1) {
209 return do_action(argv[1]);
210 } else {
211 crash1();
212 }
213
214 return 0;
215 }
216