1 // RUN: %clangxx_cfi_dso -DSHARED_LIB %s -fPIC -shared -o %t1-so.so 2 // RUN: %clangxx_cfi_dso %s -o %t1 3 // RUN: %expect_crash %t1 2>&1 | FileCheck --check-prefix=CFI %s 4 // RUN: %expect_crash %t1 cast 2>&1 | FileCheck --check-prefix=CFI-CAST %s 5 // RUN: %expect_crash %t1 dlclose 2>&1 | FileCheck --check-prefix=CFI %s 6 7 // RUN: %clangxx_cfi_dso -DB32 -DSHARED_LIB %s -fPIC -shared -o %t2-so.so 8 // RUN: %clangxx_cfi_dso -DB32 %s -o %t2 9 // RUN: %expect_crash %t2 2>&1 | FileCheck --check-prefix=CFI %s 10 // RUN: %expect_crash %t2 cast 2>&1 | FileCheck --check-prefix=CFI-CAST %s 11 // RUN: %expect_crash %t2 dlclose 2>&1 | FileCheck --check-prefix=CFI %s 12 13 // RUN: %clangxx_cfi_dso -DB64 -DSHARED_LIB %s -fPIC -shared -o %t3-so.so 14 // RUN: %clangxx_cfi_dso -DB64 %s -o %t3 15 // RUN: %expect_crash %t3 2>&1 | FileCheck --check-prefix=CFI %s 16 // RUN: %expect_crash %t3 cast 2>&1 | FileCheck --check-prefix=CFI-CAST %s 17 // RUN: %expect_crash %t3 dlclose 2>&1 | FileCheck --check-prefix=CFI %s 18 19 // RUN: %clangxx_cfi_dso -DBM -DSHARED_LIB %s -fPIC -shared -o %t4-so.so 20 // RUN: %clangxx_cfi_dso -DBM %s -o %t4 21 // RUN: %expect_crash %t4 2>&1 | FileCheck --check-prefix=CFI %s 22 // RUN: %expect_crash %t4 cast 2>&1 | FileCheck --check-prefix=CFI-CAST %s 23 // RUN: %expect_crash %t4 dlclose 2>&1 | FileCheck --check-prefix=CFI %s 24 25 // RUN: %clangxx -g -DBM -DSHARED_LIB -DNOCFI %s -fPIC -shared -o %t5-so.so 26 // RUN: %clangxx -g -DBM -DNOCFI %s -ldl -o %t5 27 // RUN: %t5 2>&1 | FileCheck --check-prefix=NCFI %s 28 // RUN: %t5 cast 2>&1 | FileCheck --check-prefix=NCFI %s 29 // RUN: %t5 dlclose 2>&1 | FileCheck --check-prefix=NCFI %s 30 31 // Test that calls to uninstrumented library are unchecked. 32 // RUN: %clangxx -DBM -DSHARED_LIB %s -fPIC -shared -o %t6-so.so 33 // RUN: %clangxx_cfi_dso -DBM %s -o %t6 34 // RUN: %t6 2>&1 | FileCheck --check-prefix=NCFI %s 35 // RUN: %t6 cast 2>&1 | FileCheck --check-prefix=NCFI %s 36 37 // Call-after-dlclose is checked on the caller side. 38 // RUN: %expect_crash %t6 dlclose 2>&1 | FileCheck --check-prefix=CFI %s 39 40 // Tests calls into dlopen-ed library. 41 // REQUIRES: cxxabi 42 43 #include <assert.h> 44 #include <dlfcn.h> 45 #include <stdio.h> 46 #include <stdint.h> 47 #include <string.h> 48 #include <sys/mman.h> 49 50 #include <string> 51 52 struct A { 53 virtual void f(); 54 }; 55 56 #ifdef SHARED_LIB 57 58 #include "../utils.h" 59 struct B { 60 virtual void f(); 61 }; 62 void B::f() {} 63 64 extern "C" void *create_B() { 65 create_derivers<B>(); 66 return (void *)(new B()); 67 } 68 69 extern "C" __attribute__((aligned(4096))) void do_nothing() {} 70 71 #else 72 73 void A::f() {} 74 75 static const int kCodeAlign = 4096; 76 static const int kCodeSize = 4096; 77 static char saved_code[kCodeSize]; 78 static char *real_start; 79 80 static void save_code(char *p) { 81 real_start = (char *)(((uintptr_t)p) & ~(kCodeAlign - 1)); 82 memcpy(saved_code, real_start, kCodeSize); 83 } 84 85 static void restore_code() { 86 char *code = (char *)mmap(real_start, kCodeSize, PROT_WRITE | PROT_EXEC, 87 MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, 0, 0); 88 assert(code == real_start); 89 memcpy(code, saved_code, kCodeSize); 90 } 91 92 int main(int argc, char *argv[]) { 93 const bool test_cast = argc > 1 && strcmp(argv[1], "cast") == 0; 94 const bool test_dlclose = argc > 1 && strcmp(argv[1], "dlclose") == 0; 95 96 std::string name = std::string(argv[0]) + "-so.so"; 97 void *handle = dlopen(name.c_str(), RTLD_NOW); 98 assert(handle); 99 void *(*create_B)() = (void *(*)())dlsym(handle, "create_B"); 100 assert(create_B); 101 102 void *p = create_B(); 103 A *a; 104 105 // CFI: =0= 106 // CFI-CAST: =0= 107 // NCFI: =0= 108 fprintf(stderr, "=0=\n"); 109 110 if (test_cast) { 111 // Test cast. BOOM. 112 a = (A*)p; 113 } else { 114 // Invisible to CFI. Test virtual call later. 115 memcpy(&a, &p, sizeof(a)); 116 } 117 118 // CFI: =1= 119 // CFI-CAST-NOT: =1= 120 // NCFI: =1= 121 fprintf(stderr, "=1=\n"); 122 123 if (test_dlclose) { 124 // Imitate an attacker sneaking in an executable page where a dlclose()d 125 // library was loaded. This needs to pass w/o CFI, so for the testing 126 // purpose, we just copy the bytes of a "void f() {}" function back and 127 // forth. 128 void (*do_nothing)() = (void (*)())dlsym(handle, "do_nothing"); 129 assert(do_nothing); 130 save_code((char *)do_nothing); 131 132 int res = dlclose(handle); 133 assert(res == 0); 134 135 restore_code(); 136 137 do_nothing(); // UB here 138 } else { 139 a->f(); // UB here 140 } 141 142 // CFI-NOT: =2= 143 // CFI-CAST-NOT: =2= 144 // NCFI: =2= 145 fprintf(stderr, "=2=\n"); 146 } 147 #endif 148
