rsundahl updated this revision to Diff 428731.
rsundahl marked 6 inline comments as done.
rsundahl added a comment.
Update diff back to dc7e02d4b4dc30d44ddebd832719a6e63396e718
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D125195/new/
https://reviews.llvm.org/D125195
Files:
clang/lib/CodeGen/ItaniumCXXABI.cpp
compiler-rt/lib/asan/asan_poisoning.cpp
compiler-rt/test/asan/TestCases/Posix/new_array_cookie_test.cpp
compiler-rt/test/asan/TestCases/Posix/new_array_cookie_uaf_test.cpp
compiler-rt/test/asan/TestCases/Posix/new_array_cookie_with_new_from_class.cpp
Index: compiler-rt/test/asan/TestCases/Posix/new_array_cookie_with_new_from_class.cpp
===================================================================
--- compiler-rt/test/asan/TestCases/Posix/new_array_cookie_with_new_from_class.cpp
+++ compiler-rt/test/asan/TestCases/Posix/new_array_cookie_with_new_from_class.cpp
@@ -1,16 +1,22 @@
-// Test that we do not poison the array cookie if the operator new is defined
-// inside the class.
-// RUN: %clangxx_asan %s -o %t && %run %t
+// For arrays allocated by classes that define their own custom "new", ASAN
+// should NOT poison the array cookie unless the compilation unit is compiled
+// with "-fsanitize-address-poison-custom-array-cookie".
+// Here we test that:
+// 1) w/o ASan, the array cookie location IS writable
+// 2) w/ASan, the array cookie location IS writeable by default
+// 3) w/ASan, the flag "-fno-sanitize-address-poison-custom-array-cookie"
+// is a NOP (because this is the default) and finally,
+// 4) w/ASan AND "-fsanitize-address-poison-custom-array-cookie", the
+// array cookie location is NOT writable (ASAN successfully stopped it)
//
-// XFAIL: arm
+// RUN: %clangxx %s -o %t && %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_asan %s -o %t && %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_asan -fno-sanitize-address-poison-custom-array-cookie %s -o %t && %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_asan -fsanitize-address-poison-custom-array-cookie %s -o %t && not %run %t 2>&1 | FileCheck %s --check-prefix=COOKIE
-// UNSUPPORTED: ios
-
-#include <new>
-#include <stdlib.h>
-#include <stdint.h>
-#include <stdio.h>
#include <assert.h>
+#include <stdio.h>
+
struct Foo {
void *operator new(size_t s) { return Allocate(s); }
void *operator new[] (size_t s) { return Allocate(s); }
@@ -22,7 +28,6 @@
}
};
-Foo::~Foo() {}
void *Foo::allocated;
Foo *getFoo(size_t n) {
@@ -33,8 +38,12 @@
Foo *foo = getFoo(10);
fprintf(stderr, "foo : %p\n", foo);
fprintf(stderr, "alloc: %p\n", Foo::allocated);
- assert(reinterpret_cast<uintptr_t>(foo) ==
- reinterpret_cast<uintptr_t>(Foo::allocated) + sizeof(void*));
- *reinterpret_cast<uintptr_t*>(Foo::allocated) = 42;
+ reinterpret_cast<char*>(foo)[-1] = 42;
+// COOKIE: AddressSanitizer: heap-buffer-overflow
+// COOKIE: in main {{.*}}new_array_cookie_with_new_from_class.cpp:[[@LINE-2]]
+// COOKIE: is located {{7 bytes inside of 18|15 bytes inside of 26}}-byte region
+ printf("Unsurprisingly, we were able to write to the array cookie\n");
+// CHECK: Unsurprisingly, we were able to write to the array cookie
+
return 0;
}
Index: compiler-rt/test/asan/TestCases/Posix/new_array_cookie_uaf_test.cpp
===================================================================
--- compiler-rt/test/asan/TestCases/Posix/new_array_cookie_uaf_test.cpp
+++ compiler-rt/test/asan/TestCases/Posix/new_array_cookie_uaf_test.cpp
@@ -3,15 +3,10 @@
// RUN: %env_asan_opts=poison_array_cookie=1 not %run %t 2>&1 | FileCheck %s --check-prefix=COOKIE
// RUN: %env_asan_opts=poison_array_cookie=0 not %run %t 2>&1 | FileCheck %s --check-prefix=NO_COOKIE
-// UNSUPPORTED: ios
-
-// Added to allow enabling of tests but needs investigation (rdar://91448627)
-// XFAIL: (darwin && (arm64-target-arch || arm64e-target-arch))
-
-#include <stdio.h>
-#include <stdlib.h>
#include <assert.h>
-int dtor_counter;
+#include <stdio.h>
+
+int dtor_counter=0;
struct C {
int x;
~C() {
@@ -22,12 +17,11 @@
__attribute__((noinline)) void Delete(C *c) { delete[] c; }
__attribute__((no_sanitize_address)) void Write42ToCookie(C *c) {
- long *p = reinterpret_cast<long*>(c);
- p[-1] = 42;
+ reinterpret_cast<size_t*>(c)[-1] = 42;
}
int main(int argc, char **argv) {
- C *buffer = new C[argc];
+ C *buffer = new C[1];
delete [] buffer;
Write42ToCookie(buffer);
delete [] buffer;
Index: compiler-rt/test/asan/TestCases/Posix/new_array_cookie_test.cpp
===================================================================
--- compiler-rt/test/asan/TestCases/Posix/new_array_cookie_test.cpp
+++ compiler-rt/test/asan/TestCases/Posix/new_array_cookie_test.cpp
@@ -1,16 +1,12 @@
// REQUIRES: asan-64-bits
// RUN: %clangxx_asan -O3 %s -o %t
-// RUN: not %run %t 2>&1 | FileCheck %s
+// RUN: not %run %t 2>&1 | FileCheck %s
// RUN: %env_asan_opts=poison_array_cookie=1 not %run %t 2>&1 | FileCheck %s
// RUN: %env_asan_opts=poison_array_cookie=0 not %run %t 2>&1 | FileCheck %s --check-prefix=NO_COOKIE
-// UNSUPPORTED: ios
-
-// Added to allow enabling of tests but needs investigation (rdar://91448627)
-// XFAIL: (darwin && (arm64-target-arch || arm64e-target-arch))
-
#include <stdio.h>
#include <stdlib.h>
+
struct C {
int x;
~C() {
@@ -20,11 +16,11 @@
};
int main(int argc, char **argv) {
- C *buffer = new C[argc];
- buffer[-2].x = 10;
+ C *buffer = new C[1];
+ reinterpret_cast<char*>(buffer)[-1] = 42;
// CHECK: AddressSanitizer: heap-buffer-overflow
// CHECK: in main {{.*}}new_array_cookie_test.cpp:[[@LINE-2]]
-// CHECK: is located 0 bytes inside of 12-byte region
+// CHECK: is located {{7 bytes inside of 12|15 bytes inside of 20}}-byte region
// NO_COOKIE: ZZZZZZZZ
delete [] buffer;
}
Index: compiler-rt/lib/asan/asan_poisoning.cpp
===================================================================
--- compiler-rt/lib/asan/asan_poisoning.cpp
+++ compiler-rt/lib/asan/asan_poisoning.cpp
@@ -259,6 +259,10 @@
if (!flags()->poison_array_cookie) return;
uptr s = MEM_TO_SHADOW(p);
*reinterpret_cast<u8*>(s) = kAsanArrayCookieMagic;
+#if SANITIZER_ARM64
+ // The ARM64 cookie has a second "size_t" entry so poison it as well
+ *(reinterpret_cast<u8*>(s)-1) = kAsanArrayCookieMagic;
+#endif
}
extern "C" SANITIZER_INTERFACE_ATTRIBUTE
Index: clang/lib/CodeGen/ItaniumCXXABI.cpp
===================================================================
--- clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -2424,6 +2424,8 @@
QualType elementType) {
assert(requiresArrayCookie(expr));
+ unsigned AS = newPtr.getAddressSpace();
+
// The cookie is always at the start of the buffer.
Address cookie = newPtr;
@@ -2435,7 +2437,20 @@
// The second element is the element count.
cookie = CGF.Builder.CreateConstInBoundsGEP(cookie, 1);
- CGF.Builder.CreateStore(numElements, cookie);
+ llvm::Instruction *SI = CGF.Builder.CreateStore(numElements, cookie);
+
+ // Handle poisoning the array cookie in asan
+ if (CGM.getLangOpts().Sanitize.has(SanitizerKind::Address) && AS == 0 &&
+ (expr->getOperatorNew()->isReplaceableGlobalAllocationFunction() ||
+ CGM.getCodeGenOpts().SanitizeAddressPoisonCustomArrayCookie)) {
+ // The store to the CookiePtr does not need to be instrumented.
+ CGM.getSanitizerMetadata()->disableSanitizerForInstruction(SI);
+ llvm::FunctionType *FTy =
+ llvm::FunctionType::get(CGM.VoidTy, cookie.getType(), false);
+ llvm::FunctionCallee F =
+ CGM.CreateRuntimeFunction(FTy, "__asan_poison_cxx_array_cookie");
+ CGF.Builder.CreateCall(F, cookie.getRawPointer(CGF));
+ }
// Finally, compute a pointer to the actual data buffer by skipping
// over the cookie completely.
@@ -2446,13 +2461,28 @@
llvm::Value *ARMCXXABI::readArrayCookieImpl(CodeGenFunction &CGF,
Address allocPtr,
CharUnits cookieSize) {
+ unsigned AS = allocPtr.getAddressSpace();
+
// The number of elements is at offset sizeof(size_t) relative to
// the allocated pointer.
Address numElementsPtr
= CGF.Builder.CreateConstInBoundsByteGEP(allocPtr, CGF.getSizeSize());
numElementsPtr = CGF.Builder.CreateElementBitCast(numElementsPtr, CGF.SizeTy);
- return CGF.Builder.CreateLoad(numElementsPtr);
+
+ if (!CGM.getLangOpts().Sanitize.has(SanitizerKind::Address) || AS != 0)
+ return CGF.Builder.CreateLoad(numElementsPtr);
+
+ // In asan mode emit a function call instead of a regular load and let the
+ // run-time deal with it: if the shadow is properly poisoned return the
+ // cookie, otherwise return 0 to avoid an infinite loop calling DTORs.
+ // We can't simply ignore this load using nosanitize metadata because
+ // the metadata may be lost.
+ llvm::FunctionType *FTy =
+ llvm::FunctionType::get(CGF.SizeTy, CGF.SizeTy->getPointerTo(0), false);
+ llvm::FunctionCallee F =
+ CGM.CreateRuntimeFunction(FTy, "__asan_load_cxx_array_cookie");
+ return CGF.Builder.CreateCall(F, numElementsPtr.getRawPointer(CGF));
}
/*********************** Static local initialization **************************/
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