Daniel Krupp 289725f11c
[analyzer] New optin.taint.TaintedAlloc checker for catching unbounded memory allocation calls (#92420)
A new optional checker (optin.taint.TaintedAlloc) will warn if a memory
allocation function (malloc, calloc, realloc, alloca, operator new[]) is
called with a tainted (attacker controlled) size parameter.
A large, maliciously set size value can trigger memory exhaustion. To
get this warning, the alpha.security.taint.TaintPropagation checker also
needs to be switched on.

The warning will only be emitted, if the analyzer cannot prove that the
size is below reasonable bounds (<SIZE_MAX/4).
2024-06-05 16:33:31 +02:00

244 lines
6.3 KiB
C++

// RUN: %clang_analyze_cc1 -w -verify %s \
// RUN: -analyzer-checker=core \
// RUN: -analyzer-checker=alpha.deadcode.UnreachableCode \
// RUN: -analyzer-checker=alpha.core.CastSize \
// RUN: -analyzer-checker=unix.Malloc \
// RUN: -analyzer-checker=cplusplus.NewDelete \
// RUN: -analyzer-checker=alpha.security.taint.TaintPropagation \
// RUN: -analyzer-checker=optin.taint.TaintedAlloc
// RUN: %clang_analyze_cc1 -w -verify %s \
// RUN: -triple i386-unknown-linux-gnu \
// RUN: -analyzer-checker=core \
// RUN: -analyzer-checker=alpha.deadcode.UnreachableCode \
// RUN: -analyzer-checker=alpha.core.CastSize \
// RUN: -analyzer-checker=unix.Malloc \
// RUN: -analyzer-checker=cplusplus.NewDelete \
// RUN: -analyzer-checker=alpha.security.taint.TaintPropagation \
// RUN: -analyzer-checker=optin.taint.TaintedAlloc
// RUN: %clang_analyze_cc1 -w -verify %s -DTEST_INLINABLE_ALLOCATORS \
// RUN: -analyzer-checker=core \
// RUN: -analyzer-checker=alpha.deadcode.UnreachableCode \
// RUN: -analyzer-checker=alpha.core.CastSize \
// RUN: -analyzer-checker=unix.Malloc \
// RUN: -analyzer-checker=cplusplus.NewDelete \
// RUN: -analyzer-checker=alpha.security.taint.TaintPropagation \
// RUN: -analyzer-checker=optin.taint.TaintedAlloc
// RUN: %clang_analyze_cc1 -w -verify %s -DTEST_INLINABLE_ALLOCATORS \
// RUN: -triple i386-unknown-linux-gnu \
// RUN: -analyzer-checker=core \
// RUN: -analyzer-checker=alpha.deadcode.UnreachableCode \
// RUN: -analyzer-checker=alpha.core.CastSize \
// RUN: -analyzer-checker=unix.Malloc \
// RUN: -analyzer-checker=cplusplus.NewDelete \
// RUN: -analyzer-checker=alpha.security.taint.TaintPropagation \
// RUN: -analyzer-checker=optin.taint.TaintedAlloc
#include "Inputs/system-header-simulator-cxx.h"
typedef __typeof(sizeof(int)) size_t;
void *malloc(size_t);
void free(void *);
void *realloc(void *ptr, size_t size);
void *calloc(size_t nmemb, size_t size);
char *strdup(const char *s);
int scanf( const char* format, ... );
void taintAlloc() {
size_t size = 0;
scanf("%zu", &size);
int *ptr = new int[size];// expected-warning{{Memory allocation function is called with a tainted (potentially attacker controlled) value}}
delete[] ptr;
}
void checkThatMallocCheckerIsRunning() {
malloc(4);
} // expected-warning{{leak}}
struct Foo {
mutable void* m_data;
Foo(void* data) : m_data(data) {}
};
Foo aFunction() {
return malloc(10);
}
// Assume that functions which take a function pointer can free memory even if
// they are defined in system headers and take the const pointer to the
// allocated memory.
// Test default parameter.
int const_ptr_and_callback_def_param(int, const char*, int n, void(*)(void*) = free);
void r11160612_3() {
char *x = (char*)malloc(12);
const_ptr_and_callback_def_param(0, x, 12);
}
int const_ptr_and_callback_def_param_null(int, const char*, int n, void(*)(void*) = 0);
void r11160612_no_callback() {
char *x = (char*)malloc(12);
const_ptr_and_callback_def_param_null(0, x, 12);
} // expected-warning{{leak}}
// Test member function pointer.
struct CanFreeMemory {
static void myFree(void*);
};
//This is handled because we look at the type of the parameter(not argument).
void r11160612_3(CanFreeMemory* p) {
char *x = (char*)malloc(12);
const_ptr_and_callback_def_param(0, x, 12, p->myFree);
}
namespace PR13751 {
class OwningVector {
void **storage;
size_t length;
public:
OwningVector();
~OwningVector();
void push_back(void *Item) {
storage[length++] = Item;
}
};
void testDestructors() {
OwningVector v;
v.push_back(malloc(4));
// no leak warning; freed in destructor
}
}
struct X { void *a; };
struct X get() {
struct X result;
result.a = malloc(4);
return result; // no-warning
}
// Ensure that regions accessible through a LazyCompoundVal trigger region escape.
// Malloc checker used to report leaks for the following two test cases.
struct Property {
char* getterName;
Property(char* n)
: getterName(n) {}
};
void append(Property x);
void appendWrapper(char *getterName) {
append(Property(getterName));
}
void foo(const char* name) {
char* getterName = strdup(name);
appendWrapper(getterName); // no-warning
}
struct NestedProperty {
Property prop;
NestedProperty(Property p)
: prop(p) {}
};
void appendNested(NestedProperty x);
void appendWrapperNested(char *getterName) {
appendNested(NestedProperty(Property(getterName)));
}
void fooNested(const char* name) {
char* getterName = strdup(name);
appendWrapperNested(getterName); // no-warning
}
namespace PR31226 {
struct b2 {
int f;
};
struct b1 : virtual b2 {
void m();
};
struct d : b1, b2 {
};
void f() {
d *p = new d();
p->m(); // no-crash // no-warning
}
}
// Allow __cxa_demangle to escape.
char* test_cxa_demangle(const char* sym) {
size_t funcnamesize = 256;
char* funcname = (char*)malloc(funcnamesize);
int status;
char* ret = abi::__cxa_demangle(sym, funcname, &funcnamesize, &status);
if (status == 0) {
funcname = ret;
}
return funcname; // no-warning
}
namespace argument_leak {
class A {
char *name;
public:
char *getName() {
if (!name) {
name = static_cast<char *>(malloc(10));
}
return name;
}
~A() {
if (name) {
delete[] name;
}
}
};
void test(A a) {
(void)a.getName();
}
} // namespace argument_leak
#define ZERO_SIZE_PTR ((void *)16)
void test_delete_ZERO_SIZE_PTR() {
int *Ptr = (int *)ZERO_SIZE_PTR;
// ZERO_SIZE_PTR is specially handled but only for malloc family
delete Ptr; // expected-warning{{Argument to 'delete' is a constant address (16)}}
}
namespace pr46253_class {
class a {
void *realloc(int, bool = false) { realloc(1); } // no-crash
};
} // namespace pr46253_class
namespace pr46253_retty{
void realloc(void *ptr, size_t size) { realloc(ptr, size); } // no-crash
} // namespace pr46253_retty
namespace pr46253_paramty{
void *realloc(void **ptr, size_t size) { realloc(ptr, size); } // no-crash
} // namespace pr46253_paramty
namespace pr46253_paramty2{
void *realloc(void *ptr, int size) { realloc(ptr, size); } // no-crash
} // namespace pr46253_paramty2
namespace pr81597 {
struct S {};
struct T {
void free(const S& s);
};
void f(T& t) {
S s;
t.free(s); // no-warning: This is not the free you are looking for...
}
} // namespace pr81597