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 static void* global = 0; // So GCC doesn't optimize the tail recursion out of overflow_stack.
55
overflow_stack(void * p)56 __attribute__((noinline)) static void overflow_stack(void* p) {
57 void* buf[1];
58 buf[0] = p;
59 global = buf;
60 overflow_stack(&buf);
61 }
62
noisy(void * x)63 static void *noisy(void *x)
64 {
65 char c = (uintptr_t) x;
66 for(;;) {
67 usleep(250*1000);
68 write(2, &c, 1);
69 if(c == 'C') *((volatile unsigned*) 0) = 42;
70 }
71 return NULL;
72 }
73
ctest()74 static int ctest()
75 {
76 pthread_t thr;
77 pthread_attr_t attr;
78 pthread_attr_init(&attr);
79 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
80 pthread_create(&thr, &attr, noisy, (void*) 'A');
81 pthread_create(&thr, &attr, noisy, (void*) 'B');
82 pthread_create(&thr, &attr, noisy, (void*) 'C');
83 for(;;) ;
84 return 0;
85 }
86
thread_callback(void * raw_arg)87 static void* thread_callback(void* raw_arg)
88 {
89 return (void*) (uintptr_t) do_action((const char*) raw_arg);
90 }
91
do_action_on_thread(const char * arg)92 static int do_action_on_thread(const char* arg)
93 {
94 pthread_t t;
95 pthread_create(&t, NULL, thread_callback, (void*) arg);
96 void* result = NULL;
97 pthread_join(t, &result);
98 return (int) (uintptr_t) result;
99 }
100
crash3(int a)101 __attribute__((noinline)) static int crash3(int a) {
102 *((int*) 0xdead) = a;
103 return a*4;
104 }
105
crash2(int a)106 __attribute__((noinline)) static int crash2(int a) {
107 a = crash3(a) + 2;
108 return a*3;
109 }
110
crash(int a)111 __attribute__((noinline)) static int crash(int a) {
112 a = crash2(a) + 1;
113 return a*2;
114 }
115
abuse_heap()116 static void abuse_heap() {
117 char buf[16];
118 free((void*) buf); // GCC is smart enough to warn about this, but we're doing it deliberately.
119 }
120
sigsegv_non_null()121 static void sigsegv_non_null() {
122 int* a = (int *)(&do_action);
123 *a = 42;
124 }
125
do_action(const char * arg)126 static int do_action(const char* arg)
127 {
128 fprintf(stderr,"crasher: init pid=%d tid=%d\n", getpid(), gettid());
129
130 if (!strncmp(arg, "thread-", strlen("thread-"))) {
131 return do_action_on_thread(arg + strlen("thread-"));
132 } else if (!strcmp(arg, "SIGSEGV-non-null")) {
133 sigsegv_non_null();
134 } else if (!strcmp(arg, "smash-stack")) {
135 volatile int len = 128;
136 return smash_stack(&len);
137 } else if (!strcmp(arg, "stack-overflow")) {
138 overflow_stack(NULL);
139 } else if (!strcmp(arg, "nostack")) {
140 crashnostack();
141 } else if (!strcmp(arg, "ctest")) {
142 return ctest();
143 } else if (!strcmp(arg, "exit")) {
144 exit(1);
145 } else if (!strcmp(arg, "crash") || !strcmp(arg, "SIGSEGV")) {
146 return crash(42);
147 } else if (!strcmp(arg, "abort")) {
148 maybe_abort();
149 } else if (!strcmp(arg, "assert")) {
150 __assert("some_file.c", 123, "false");
151 } else if (!strcmp(arg, "assert2")) {
152 __assert2("some_file.c", 123, "some_function", "false");
153 } else if (!strcmp(arg, "LOG_ALWAYS_FATAL")) {
154 LOG_ALWAYS_FATAL("hello %s", "world");
155 } else if (!strcmp(arg, "LOG_ALWAYS_FATAL_IF")) {
156 LOG_ALWAYS_FATAL_IF(true, "hello %s", "world");
157 } else if (!strcmp(arg, "SIGFPE")) {
158 raise(SIGFPE);
159 return EXIT_SUCCESS;
160 } else if (!strcmp(arg, "SIGPIPE")) {
161 int pipe_fds[2];
162 pipe(pipe_fds);
163 close(pipe_fds[0]);
164 write(pipe_fds[1], "oops", 4);
165 return EXIT_SUCCESS;
166 } else if (!strcmp(arg, "SIGTRAP")) {
167 raise(SIGTRAP);
168 return EXIT_SUCCESS;
169 } else if (!strcmp(arg, "heap-usage")) {
170 abuse_heap();
171 } else if (!strcmp(arg, "SIGSEGV-unmapped")) {
172 char* map = mmap(NULL, sizeof(int), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
173 munmap(map, sizeof(int));
174 map[0] = '8';
175 }
176
177 fprintf(stderr, "%s OP\n", __progname);
178 fprintf(stderr, "where OP is:\n");
179 fprintf(stderr, " smash-stack overwrite a stack-guard canary\n");
180 fprintf(stderr, " stack-overflow recurse until the stack overflows\n");
181 fprintf(stderr, " heap-corruption cause a libc abort by corrupting the heap\n");
182 fprintf(stderr, " heap-usage cause a libc abort by abusing a heap function\n");
183 fprintf(stderr, " nostack crash with a NULL stack pointer\n");
184 fprintf(stderr, " ctest (obsoleted by thread-crash?)\n");
185 fprintf(stderr, " exit call exit(1)\n");
186 fprintf(stderr, " abort call abort()\n");
187 fprintf(stderr, " assert call assert() without a function\n");
188 fprintf(stderr, " assert2 call assert() with a function\n");
189 fprintf(stderr, " LOG_ALWAYS_FATAL call LOG_ALWAYS_FATAL\n");
190 fprintf(stderr, " LOG_ALWAYS_FATAL_IF call LOG_ALWAYS_FATAL\n");
191 fprintf(stderr, " SIGFPE cause a SIGFPE\n");
192 fprintf(stderr, " SIGPIPE cause a SIGPIPE\n");
193 fprintf(stderr, " SIGSEGV cause a SIGSEGV at address 0x0 (synonym: crash)\n");
194 fprintf(stderr, " SIGSEGV-non-null cause a SIGSEGV at a non-zero address\n");
195 fprintf(stderr, " SIGSEGV-unmapped mmap/munmap a region of memory and then attempt to access it\n");
196 fprintf(stderr, " SIGTRAP cause a SIGTRAP\n");
197 fprintf(stderr, "prefix any of the above with 'thread-' to not run\n");
198 fprintf(stderr, "on the process' main thread.\n");
199 return EXIT_SUCCESS;
200 }
201
main(int argc,char ** argv)202 int main(int argc, char **argv)
203 {
204 fprintf(stderr,"crasher: built at " __TIME__ "!@\n");
205
206 if(argc > 1) {
207 return do_action(argv[1]);
208 } else {
209 crash1();
210 }
211
212 return 0;
213 }
214