// RUN: %clang_analyze_cc1 -w -analyzer-checker=core,osx.MIG -std=c++14 \
// RUN: -analyzer-output=text -fblocks -verify %s
typedef unsigned uint32_t;
// XNU APIs.
typedef int kern_return_t;
#define KERN_SUCCESS 0
#define KERN_ERROR 1
#define MIG_NO_REPLY (-305)
typedef unsigned mach_port_name_t;
typedef unsigned vm_address_t;
typedef unsigned vm_size_t;
typedef void *ipc_space_t;
typedef unsigned long io_user_reference_t;
typedef struct ipc_port *ipc_port_t;
typedef unsigned mach_port_t;
typedef uint32_t UInt32;
struct os_refcnt {};
typedef struct os_refcnt os_refcnt_t;
struct thread {
os_refcnt_t ref_count;
};
typedef struct thread *thread_t;
kern_return_t vm_deallocate(mach_port_name_t, vm_address_t, vm_size_t);
kern_return_t mach_vm_deallocate(mach_port_name_t, vm_address_t, vm_size_t);
void mig_deallocate(vm_address_t, vm_size_t);
kern_return_t mach_port_deallocate(ipc_space_t, mach_port_name_t);
void ipc_port_release(ipc_port_t);
void thread_deallocate(thread_t);
static void os_ref_retain(struct os_refcnt *rc);
#define thread_reference_internal(thread) os_ref_retain(&(thread)->ref_count);
#define MIG_SERVER_ROUTINE __attribute__((mig_server_routine))
// IOKit wrappers.
class OSObject;
typedef kern_return_t IOReturn;
#define kIOReturnError 1
enum {
kOSAsyncRef64Count = 8,
};
typedef io_user_reference_t OSAsyncReference64[kOSAsyncRef64Count];
struct IOExternalMethodArguments {
io_user_reference_t *asyncReference;
};
struct IOExternalMethodDispatch {};
class IOUserClient {
public:
static IOReturn releaseAsyncReference64(OSAsyncReference64);
static IOReturn releaseNotificationPort(mach_port_t port);
MIG_SERVER_ROUTINE
virtual IOReturn externalMethod(
uint32_t selector, IOExternalMethodArguments *arguments,
IOExternalMethodDispatch *dispatch = 0, OSObject *target = 0,
void *reference = 0);
MIG_SERVER_ROUTINE
virtual IOReturn registerNotificationPort(mach_port_t, UInt32, UInt32);
};
// Tests.
MIG_SERVER_ROUTINE
kern_return_t basic_test(mach_port_name_t port, vm_address_t address, vm_size_t size) {
vm_deallocate(port, address, size); // expected-note{{Value passed through parameter 'address' is deallocated}}
if (size > 10) { // expected-note{{Assuming 'size' is > 10}}
// expected-note@-1{{Taking true branch}}
return KERN_ERROR; // expected-warning{{MIG callback fails with error after deallocating argument value. This is a use-after-free vulnerability because the caller will try to deallocate it again}}
// expected-note@-1{{MIG callback fails with error after deallocating argument value. This is a use-after-free vulnerability because the caller will try to deallocate it again}}
}
return KERN_SUCCESS;
}
MIG_SERVER_ROUTINE
kern_return_t test_unknown_return_value(mach_port_name_t port, vm_address_t address, vm_size_t size) {
extern kern_return_t foo();
vm_deallocate(port, address, size);
// We don't know if it's a success or a failure.
return foo(); // no-warning
}
// Make sure we don't crash when they forgot to write the return statement.
MIG_SERVER_ROUTINE
kern_return_t no_crash(mach_port_name_t port, vm_address_t address, vm_size_t size) {
vm_deallocate(port, address, size);
}
// When releasing two parameters, add a note for both of them.
// Also when returning a variable, explain why do we think that it contains
// a non-success code.
MIG_SERVER_ROUTINE
kern_return_t release_twice(mach_port_name_t port, vm_address_t addr1, vm_address_t addr2, vm_size_t size) {
kern_return_t ret = KERN_ERROR; // expected-note{{'ret' initialized to 1}}
vm_deallocate(port, addr1, size); // expected-note{{Value passed through parameter 'addr1' is deallocated}}
vm_deallocate(port, addr2, size); // expected-note{{Value passed through parameter 'addr2' is deallocated}}
return ret; // expected-warning{{MIG callback fails with error after deallocating argument value. This is a use-after-free vulnerability because the caller will try to deallocate it again}}
// expected-note@-1{{MIG callback fails with error after deallocating argument value. This is a use-after-free vulnerability because the caller will try to deallocate it again}}
}
MIG_SERVER_ROUTINE
kern_return_t no_unrelated_notes(mach_port_name_t port, vm_address_t address, vm_size_t size) {
vm_deallocate(port, address, size); // no-note
1 / 0; // expected-warning{{Division by zero}}
// expected-note@-1{{Division by zero}}
return KERN_SUCCESS;
}
// Make sure we find the bug when the object is destroyed within an
// automatic destructor.
MIG_SERVER_ROUTINE
kern_return_t test_vm_deallocate_in_automatic_dtor(mach_port_name_t port, vm_address_t address, vm_size_t size) {
struct WillDeallocate {
mach_port_name_t port;
vm_address_t address;
vm_size_t size;
~WillDeallocate() {
vm_deallocate(port, address, size); // expected-note{{Value passed through parameter 'address' is deallocated}}
}
} will_deallocate{port, address, size};
if (size > 10) {
// expected-note@-1{{Assuming 'size' is > 10}}
// expected-note@-2{{Taking true branch}}
return KERN_ERROR;
// expected-note@-1{{Calling '~WillDeallocate'}}
// expected-note@-2{{Returning from '~WillDeallocate'}}
// expected-warning@-3{{MIG callback fails with error after deallocating argument value. This is a use-after-free vulnerability because the caller will try to deallocate it again}}
// expected-note@-4 {{MIG callback fails with error after deallocating argument value. This is a use-after-free vulnerability because the caller will try to deallocate it again}}
}
return KERN_SUCCESS;
}
// Check that we work on Objective-C messages and blocks.
@interface I
- (kern_return_t)fooAtPort:(mach_port_name_t)port withAddress:(vm_address_t)address ofSize:(vm_size_t)size;
@end
@implementation I
- (kern_return_t)fooAtPort:(mach_port_name_t)port
withAddress:(vm_address_t)address
ofSize:(vm_size_t)size MIG_SERVER_ROUTINE {
vm_deallocate(port, address, size); // expected-note{{Value passed through parameter 'address' is deallocated}}
return KERN_ERROR; // expected-warning{{MIG callback fails with error after deallocating argument value. This is a use-after-free vulnerability because the caller will try to deallocate it again}}
// expected-note@-1{{MIG callback fails with error after deallocating argument value. This is a use-after-free vulnerability because the caller will try to deallocate it again}}
}
@end
void test_block() {
kern_return_t (^block)(mach_port_name_t, vm_address_t, vm_size_t) =
^MIG_SERVER_ROUTINE (mach_port_name_t port,
vm_address_t address, vm_size_t size) {
vm_deallocate(port, address, size); // expected-note{{Value passed through parameter 'address' is deallocated}}
return KERN_ERROR; // expected-warning{{MIG callback fails with error after deallocating argument value. This is a use-after-free vulnerability because the caller will try to deallocate it again}}
// expected-note@-1{{MIG callback fails with error after deallocating argument value. This is a use-after-free vulnerability because the caller will try to deallocate it again}}
};
}
void test_block_with_weird_return_type() {
struct Empty {};
// The block is written within a function so that it was actually analyzed as
// a top-level function during analysis. If we were to write it as a global
// variable of block type instead, it would not have been analyzed, because
// ASTConsumer won't find the block's code body within the VarDecl.
// At the same time, we shouldn't call it from the function, because otherwise
// it will be analyzed as an inlined function rather than as a top-level
// function.
Empty (^block)(mach_port_name_t, vm_address_t, vm_size_t) =
^MIG_SERVER_ROUTINE(mach_port_name_t port,
vm_address_t address, vm_size_t size) {
vm_deallocate(port, address, size);
return Empty{}; // no-crash
};
}
// Test various APIs.
MIG_SERVER_ROUTINE
kern_return_t test_mach_vm_deallocate(mach_port_name_t port, vm_address_t address, vm_size_t size) {
mach_vm_deallocate(port, address, size); // expected-note{{Value passed through parameter 'address' is deallocated}}
return KERN_ERROR; // expected-warning{{MIG callback fails with error after deallocating argument value}}
// expected-note@-1{{MIG callback fails with error after deallocating argument value}}
}
MIG_SERVER_ROUTINE
kern_return_t test_mach_port_deallocate(ipc_space_t space,
mach_port_name_t port) {
mach_port_deallocate(space, port); // expected-note{{Value passed through parameter 'port' is deallocated}}
return KERN_ERROR; // expected-warning{{MIG callback fails with error after deallocating argument value}}
// expected-note@-1{{MIG callback fails with error after deallocating argument value}}
}
MIG_SERVER_ROUTINE
kern_return_t test_mig_deallocate(vm_address_t address, vm_size_t size) {
mig_deallocate(address, size); // expected-note{{Value passed through parameter 'address' is deallocated}}
return KERN_ERROR; // expected-warning{{MIG callback fails with error after deallocating argument value}}
// expected-note@-1{{MIG callback fails with error after deallocating argument value}}
}
MIG_SERVER_ROUTINE
kern_return_t test_ipc_port_release(ipc_port_t port) {
ipc_port_release(port); // expected-note{{Value passed through parameter 'port' is deallocated}}
return KERN_ERROR; // expected-warning{{MIG callback fails with error after deallocating argument value}}
// expected-note@-1{{MIG callback fails with error after deallocating argument value}}
}
// Let's try the C++11 attribute spelling syntax as well.
[[clang::mig_server_routine]]
IOReturn test_releaseAsyncReference64(IOExternalMethodArguments *arguments) {
IOUserClient::releaseAsyncReference64(arguments->asyncReference); // expected-note{{Value passed through parameter 'arguments' is deallocated}}
return kIOReturnError; // expected-warning{{MIG callback fails with error after deallocating argument value}}
// expected-note@-1{{MIG callback fails with error after deallocating argument value}}
}
MIG_SERVER_ROUTINE
kern_return_t test_no_reply(ipc_space_t space, mach_port_name_t port) {
mach_port_deallocate(space, port);
return MIG_NO_REPLY; // no-warning
}
class MyClient: public IOUserClient {
// The MIG_SERVER_ROUTINE annotation is intentionally skipped.
// It should be picked up from the superclass.
IOReturn externalMethod(uint32_t selector, IOExternalMethodArguments *arguments,
IOExternalMethodDispatch *dispatch = 0, OSObject *target = 0, void *reference = 0) override {
releaseAsyncReference64(arguments->asyncReference); // expected-note{{Value passed through parameter 'arguments' is deallocated}}
return kIOReturnError; // expected-warning{{MIG callback fails with error after deallocating argument value}}
// expected-note@-1{{MIG callback fails with error after deallocating argument value}}
}
IOReturn registerNotificationPort(mach_port_t port, UInt32 x, UInt32 y) {
releaseNotificationPort(port); // expected-note{{Value passed through parameter 'port' is deallocated}}
return kIOReturnError; // expected-warning{{MIG callback fails with error after deallocating argument value}}
// expected-note@-1{{MIG callback fails with error after deallocating argument value}}
}
};
MIG_SERVER_ROUTINE
kern_return_t test_os_ref_retain(thread_t thread) {
thread_reference_internal(thread);
thread_deallocate(thread);
return KERN_ERROR; // no-warning
}
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