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
smash_stack(int i __unused)35 static int smash_stack(int i __unused) {
36 printf("crasher: deliberately corrupting stack...\n");
37 // Unless there's a "big enough" buffer on the stack, gcc
38 // doesn't bother inserting checks.
39 char buf[8];
40 // If we don't write something relatively unpredictable
41 // into the buffer and then do something with it, gcc
42 // optimizes everything away and just returns a constant.
43 *(int*)(&buf[7]) = (uintptr_t) &buf[0];
44 return *(int*)(&buf[0]);
45 }
46
47 static void* global = 0; // So GCC doesn't optimize the tail recursion out of overflow_stack.
48
overflow_stack(void * p)49 __attribute__((noinline)) static void overflow_stack(void* p) {
50 void* buf[1];
51 buf[0] = p;
52 global = buf;
53 overflow_stack(&buf);
54 }
55
noisy(void * x)56 static void *noisy(void *x)
57 {
58 char c = (uintptr_t) x;
59 for(;;) {
60 usleep(250*1000);
61 write(2, &c, 1);
62 if(c == 'C') *((unsigned*) 0) = 42;
63 }
64 return NULL;
65 }
66
ctest()67 static int ctest()
68 {
69 pthread_t thr;
70 pthread_attr_t attr;
71 pthread_attr_init(&attr);
72 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
73 pthread_create(&thr, &attr, noisy, (void*) 'A');
74 pthread_create(&thr, &attr, noisy, (void*) 'B');
75 pthread_create(&thr, &attr, noisy, (void*) 'C');
76 for(;;) ;
77 return 0;
78 }
79
thread_callback(void * raw_arg)80 static void* thread_callback(void* raw_arg)
81 {
82 return (void*) (uintptr_t) do_action((const char*) raw_arg);
83 }
84
do_action_on_thread(const char * arg)85 static int do_action_on_thread(const char* arg)
86 {
87 pthread_t t;
88 pthread_create(&t, NULL, thread_callback, (void*) arg);
89 void* result = NULL;
90 pthread_join(t, &result);
91 return (int) (uintptr_t) result;
92 }
93
crash3(int a)94 __attribute__((noinline)) static int crash3(int a) {
95 *((int*) 0xdead) = a;
96 return a*4;
97 }
98
crash2(int a)99 __attribute__((noinline)) static int crash2(int a) {
100 a = crash3(a) + 2;
101 return a*3;
102 }
103
crash(int a)104 __attribute__((noinline)) static int crash(int a) {
105 a = crash2(a) + 1;
106 return a*2;
107 }
108
abuse_heap()109 static void abuse_heap() {
110 char buf[16];
111 free((void*) buf); // GCC is smart enough to warn about this, but we're doing it deliberately.
112 }
113
sigsegv_non_null()114 static void sigsegv_non_null() {
115 int* a = (int *)(&do_action);
116 *a = 42;
117 }
118
do_action(const char * arg)119 static int do_action(const char* arg)
120 {
121 fprintf(stderr,"crasher: init pid=%d tid=%d\n", getpid(), gettid());
122
123 if (!strncmp(arg, "thread-", strlen("thread-"))) {
124 return do_action_on_thread(arg + strlen("thread-"));
125 } else if (!strcmp(arg, "SIGSEGV-non-null")) {
126 sigsegv_non_null();
127 } else if (!strcmp(arg, "smash-stack")) {
128 return smash_stack(42);
129 } else if (!strcmp(arg, "stack-overflow")) {
130 overflow_stack(NULL);
131 } else if (!strcmp(arg, "nostack")) {
132 crashnostack();
133 } else if (!strcmp(arg, "ctest")) {
134 return ctest();
135 } else if (!strcmp(arg, "exit")) {
136 exit(1);
137 } else if (!strcmp(arg, "crash") || !strcmp(arg, "SIGSEGV")) {
138 return crash(42);
139 } else if (!strcmp(arg, "abort")) {
140 maybe_abort();
141 } else if (!strcmp(arg, "assert")) {
142 __assert("some_file.c", 123, "false");
143 } else if (!strcmp(arg, "assert2")) {
144 __assert2("some_file.c", 123, "some_function", "false");
145 } else if (!strcmp(arg, "LOG_ALWAYS_FATAL")) {
146 LOG_ALWAYS_FATAL("hello %s", "world");
147 } else if (!strcmp(arg, "LOG_ALWAYS_FATAL_IF")) {
148 LOG_ALWAYS_FATAL_IF(true, "hello %s", "world");
149 } else if (!strcmp(arg, "SIGFPE")) {
150 raise(SIGFPE);
151 return EXIT_SUCCESS;
152 } else if (!strcmp(arg, "SIGPIPE")) {
153 int pipe_fds[2];
154 pipe(pipe_fds);
155 close(pipe_fds[0]);
156 write(pipe_fds[1], "oops", 4);
157 return EXIT_SUCCESS;
158 } else if (!strcmp(arg, "SIGTRAP")) {
159 raise(SIGTRAP);
160 return EXIT_SUCCESS;
161 } else if (!strcmp(arg, "heap-usage")) {
162 abuse_heap();
163 } else if (!strcmp(arg, "SIGSEGV-unmapped")) {
164 char* map = mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
165 munmap(map, sizeof(int));
166 map[0] = '8';
167 }
168
169 fprintf(stderr, "%s OP\n", __progname);
170 fprintf(stderr, "where OP is:\n");
171 fprintf(stderr, " smash-stack overwrite a stack-guard canary\n");
172 fprintf(stderr, " stack-overflow recurse until the stack overflows\n");
173 fprintf(stderr, " heap-corruption cause a libc abort by corrupting the heap\n");
174 fprintf(stderr, " heap-usage cause a libc abort by abusing a heap function\n");
175 fprintf(stderr, " nostack crash with a NULL stack pointer\n");
176 fprintf(stderr, " ctest (obsoleted by thread-crash?)\n");
177 fprintf(stderr, " exit call exit(1)\n");
178 fprintf(stderr, " abort call abort()\n");
179 fprintf(stderr, " assert call assert() without a function\n");
180 fprintf(stderr, " assert2 call assert() with a function\n");
181 fprintf(stderr, " LOG_ALWAYS_FATAL call LOG_ALWAYS_FATAL\n");
182 fprintf(stderr, " LOG_ALWAYS_FATAL_IF call LOG_ALWAYS_FATAL\n");
183 fprintf(stderr, " SIGFPE cause a SIGFPE\n");
184 fprintf(stderr, " SIGPIPE cause a SIGPIPE\n");
185 fprintf(stderr, " SIGSEGV cause a SIGSEGV at address 0x0 (synonym: crash)\n");
186 fprintf(stderr, " SIGSEGV-non-null cause a SIGSEGV at a non-zero address\n");
187 fprintf(stderr, " SIGSEGV-unmapped mmap/munmap a region of memory and then attempt to access it\n");
188 fprintf(stderr, " SIGTRAP cause a SIGTRAP\n");
189 fprintf(stderr, "prefix any of the above with 'thread-' to not run\n");
190 fprintf(stderr, "on the process' main thread.\n");
191 return EXIT_SUCCESS;
192 }
193
main(int argc,char ** argv)194 int main(int argc, char **argv)
195 {
196 fprintf(stderr,"crasher: built at " __TIME__ "!@\n");
197
198 if(argc > 1) {
199 return do_action(argv[1]);
200 } else {
201 crash1();
202 }
203
204 return 0;
205 }
206