1 // RUN: %clangxx_cfi -o %t1 %s 2 // RUN: %expect_crash_unless_devirt %t1 2>&1 | FileCheck --check-prefix=CFI %s 3 4 // RUN: %clangxx_cfi -DB32 -o %t2 %s 5 // RUN: %expect_crash %t2 2>&1 | FileCheck --check-prefix=CFI %s 6 7 // RUN: %clangxx_cfi -DB64 -o %t3 %s 8 // RUN: %expect_crash %t3 2>&1 | FileCheck --check-prefix=CFI %s 9 10 // RUN: %clangxx_cfi -DBM -o %t4 %s 11 // RUN: %expect_crash %t4 2>&1 | FileCheck --check-prefix=CFI %s 12 13 // RUN: %clangxx -o %t5 %s 14 // RUN: %t5 2>&1 | FileCheck --check-prefix=NCFI %s 15 16 // RUN: %clangxx_cfi_diag -o %t6 %s 17 // RUN: %t6 2>&1 | FileCheck --check-prefix=CFI-DIAG %s 18 19 // Tests that the CFI mechanism crashes the program when a virtual table is 20 // replaced with a compatible table of function pointers that does not belong to 21 // any class, by manually overwriting the virtual table of an object and 22 // attempting to make a call through it. 23 24 // REQUIRES: cxxabi 25 26 #include <stdio.h> 27 #include "utils.h" 28 29 struct A { 30 virtual void f(); 31 }; 32 33 void A::f() {} 34 35 void foo() { 36 fprintf(stderr, "foo\n"); 37 } 38 39 void *fake_vtable[] = { 0, 0, (void *)&foo }; 40 41 int main() { 42 create_derivers<A>(); 43 44 A *a = new A; 45 *((void **)a) = fake_vtable + 2; // UB here 46 break_optimization(a); 47 48 // CFI: 1 49 // NCFI: 1 50 fprintf(stderr, "1\n"); 51 52 // CFI-NOT: foo 53 // NCFI: foo 54 // CFI-DIAG: runtime error: control flow integrity check for type 'A' failed during virtual call 55 // CFI-DIAG-NEXT: note: invalid vtable 56 a->f(); 57 58 // We don't check for the absence of a 2 here because under devirtualization 59 // our virtual call may be devirtualized and we will proceed with execution 60 // rather than crashing. 61 62 // NCFI: {{^2$}} 63 fprintf(stderr, "2\n"); 64 } 65