Files
codeql/rust/ql/test/query-tests/security/CWE-825/lifetime.rs
2025-08-14 10:36:43 +02:00

830 lines
18 KiB
Rust

fn use_the_stack() {
let _buffer: [u8; 256] = [0xFF; 256];
}
struct MyValue {
value: i64
}
impl Drop for MyValue {
fn drop(&mut self) {
println!(" drop MyValue '{}'", self.value)
}
}
// --- local dangling ---
fn get_local_dangling() -> *const i64 {
let my_local1: i64 = 1;
return &my_local1; // $ Source[rust/access-after-lifetime-ended]=local1
} // (return value immediately becomes dangling)
fn get_local_dangling_mut() -> *mut i64 {
let mut my_local2: i64 = 2;
return &mut my_local2; // $ Source[rust/access-after-lifetime-ended]=local2
} // (return value immediately becomes dangling)
fn get_local_dangling_raw_const() -> *const i64 {
let my_local3: i64 = 3;
return &raw const my_local3; // $ Source[rust/access-after-lifetime-ended]=local3
} // (return value immediately becomes dangling)
fn get_local_dangling_raw_mut() -> *mut i64 {
let mut my_local4: i64 = 4;
return &raw mut my_local4; // $ Source[rust/access-after-lifetime-ended]=local4
} // (return value immediately becomes dangling)
fn get_param_dangling(param5: i64) -> *const i64 {
return &param5; // $ Source[rust/access-after-lifetime-ended]=param5
} // (return value immediately becomes dangling)
fn get_local_field_dangling() -> *const i64 {
let val: MyValue;
val = MyValue { value: 6 };
return &val.value; // $ Source[rust/access-after-lifetime-ended]=localfield
}
pub fn test_local_dangling() {
let p1 = get_local_dangling();
let p2 = get_local_dangling_mut();
let p3 = get_local_dangling_raw_const();
let p4 = get_local_dangling_raw_mut();
let p5 = get_param_dangling(5);
let p6 = get_local_field_dangling();
let p7: *const i64;
{
let my_local7 = 7;
p7 = &raw const my_local7; // $ Source[rust/access-after-lifetime-ended]=local7
} // (my_local goes out of scope, thus p7 is dangling)
use_the_stack();
unsafe {
let v1 = *p1; // $ Alert[rust/access-after-lifetime-ended]=local1
let v2 = *p2; // $ Alert[rust/access-after-lifetime-ended]=local2
let v3 = *p3; // $ Alert[rust/access-after-lifetime-ended]=local3
let v4 = *p4; // $ Alert[rust/access-after-lifetime-ended]=local4
let v5 = *p5; // $ Alert[rust/access-after-lifetime-ended]=param5
let v6 = *p6; // $ Alert[rust/access-after-lifetime-ended]=localfield
let v7 = *p7; // $ Alert[rust/access-after-lifetime-ended]=local7
*p2 = 8; // $ Alert[rust/access-after-lifetime-ended]=local2
*p4 = 9; // $ Alert[rust/access-after-lifetime-ended]=local4
println!(" v1 = {v1} (!)"); // corrupt in practice
println!(" v2 = {v2} (!)"); // corrupt in practice
println!(" v3 = {v3} (!)"); // corrupt in practice
println!(" v4 = {v4} (!)"); // corrupt in practice
println!(" v5 = {v5} (!)"); // corrupt in practice
println!(" v6 = {v6} (!)"); // corrupt in practice
println!(" v7 = {v7} (!)");
}
}
// --- local in scope ---
fn use_pointers(p1: *const i64, p2: *mut i64, mode: i32) {
let p3: *const i64;
let my_local1 = 1;
p3 = &my_local1;
use_the_stack();
unsafe {
if mode == 0 {
// reads
let v1 = *p1; // GOOD
let v2 = *p2; // GOOD
let v3 = *p3; // GOOD
println!(" v1 = {v1}");
println!(" v2 = {v2}");
println!(" v3 = {v3}");
}
if mode == 200 {
// writes
*p2 = 2; // GOOD
}
}
}
pub fn test_local_in_scope(mode: i32) {
let my_local3: i64 = 3;
let mut my_local_mut4: i64 = 4;
use_pointers(&my_local3, &mut my_local_mut4, mode);
}
// --- static lifetime ---
const MY_GLOBAL_CONST: i64 = 1;
fn get_const() -> *const i64 {
return &MY_GLOBAL_CONST;
}
static mut MY_GLOBAL_STATIC: i64 = 2;
fn get_static_mut() -> *mut i64 {
unsafe {
return &mut MY_GLOBAL_STATIC;
}
}
pub fn test_static(mode: i32) {
let p1 = get_const();
let p2 = get_static_mut();
use_the_stack();
unsafe {
if mode == 0 {
// reads
let v1 = *p1; // GOOD
let v2 = *p2; // GOOD
println!(" v1 = {v1}");
println!(" v2 = {v2}");
}
if mode == 210 {
// writes
*p2 = 3; // GOOD
}
}
}
// --- call contexts ---
fn access_ptr_1(ptr: *const i64) {
// only called with `ptr` safe
unsafe {
let v1 = *ptr; // GOOD
println!(" v1 = {v1}");
}
}
fn access_ptr_2(ptr: *const i64) {
// only called with `ptr` dangling
unsafe {
let v2 = *ptr; // $ Alert[rust/access-after-lifetime-ended]=local1
println!(" v2 = {v2} (!)"); // corrupt in practice
}
}
fn access_ptr_3(ptr: *const i64) {
// called from contexts with `ptr` safe and dangling
unsafe {
let v3 = *ptr; // $ MISSING: Alert
println!(" v3 = {v3} (!)"); // corrupt in practice (in one context)
}
}
fn access_and_get_dangling() -> *const i64 {
let my_local1 = 1;
let ptr = &my_local1; // $ Source[rust/access-after-lifetime-ended]=local1
access_ptr_1(ptr);
access_ptr_3(ptr);
return ptr;
} // (returned pointer becomes dangling)
pub fn test_call_contexts() {
let ptr = access_and_get_dangling();
use_the_stack();
access_ptr_2(ptr);
access_ptr_3(ptr);
}
// --- call contexts (recursive) ---
fn access_ptr_rec(ptr_up: *const i64, count: i64) -> *const i64 {
let my_local_rec = count;
let ptr_ours = &my_local_rec;
if count < 5 {
let ptr_down = access_ptr_rec(ptr_ours, count + 1);
use_the_stack();
unsafe {
let v_up = *ptr_up; // GOOD
let v_ours = *ptr_ours; // GOOD
let v_down = *ptr_down; // $ MISSING: Alert
println!(" v_up = {v_up}");
println!(" v_ours = {v_ours}");
println!(" v_down = {v_down} (!)");
}
}
return ptr_ours;
} // (returned pointer becomes dangling)
pub fn test_call_contexts_rec() {
let my_local_rec2 = 1;
let ptr_start = &my_local_rec2;
_ = access_ptr_rec(ptr_start, 2);
}
// --- loops ---
pub fn test_loop() {
let my_local1 = vec!(0);
let mut prev: *const Vec<i32> = &my_local1;
for i in 1..5 {
let my_local2 = vec!(i);
use_the_stack();
unsafe {
let v1 = (*prev)[0]; // $ MISSING: Alert[rust/access-after-lifetime-ended]=local2
println!(" v1 = {v1} (!)"); // incorrect values in practice (except first iteration)
}
prev = &my_local2; // $ Source[rust/access-after-lifetime-ended]=local2
} // (my_local2 goes out of scope, thus prev is dangling)
unsafe {
let v2 = (*prev)[0]; // $ Alert[rust/access-after-lifetime-ended]=local2
println!(" v2 = {v2} (!)"); // corrupt in practice
}
}
// --- enums ---
enum MyEnum {
Value(i64),
}
enum MyEnum2 {
Pointer(*const i64),
}
pub fn get_pointer_to_enum() -> *const MyEnum {
let e1 = MyEnum::Value(1);
let result: *const MyEnum = &e1; // $ Source[rust/access-after-lifetime-ended]=e1
result
} // (e1 goes out of scope, so result is dangling)
pub fn get_pointer_in_enum() -> MyEnum2 {
let v2 = 2;
let e2 = MyEnum2::Pointer(&v2); // $ Source[rust/access-after-lifetime-ended]=v2
e2
} // (v2 goes out of scope, so the contained pointer is dangling)
pub fn get_pointer_from_enum() -> *const i64 {
let e3 = MyEnum::Value(3);
let result: *const i64;
result = match e3 {
MyEnum::Value(x) => { &x } // $ Source[rust/access-after-lifetime-ended]=match_x
}; // (x goes out of scope, so result is possibly dangling already)
use_the_stack();
unsafe {
let v0 = *result; // ?
println!(" v0 = {v0} (?)");
}
result
} // (e3 goes out of scope, so result is definitely dangling now)
pub fn test_enums() {
let e1 = get_pointer_to_enum();
let e2 = get_pointer_in_enum();
let result = get_pointer_from_enum();
use_the_stack();
unsafe {
if let MyEnum::Value(v1) = *e1 { // $ Alert[rust/access-after-lifetime-ended]=e1
println!(" v1 = {v1} (!)"); // corrupt in practice
}
if let MyEnum2::Pointer(p2) = e2 {
let v2 = unsafe { *p2 }; // $ Alert[rust/access-after-lifetime-ended]=v2
println!(" v2 = {v2} (!)"); // corrupt in practice
}
let v3 = *result; // $ Alert[rust/access-after-lifetime-ended]=match_x
println!(" v3 = {v3} (!)"); // corrupt in practice
}
}
// --- recursive enum ---
enum RecursiveEnum {
Wrapper(Box<RecursiveEnum>),
Pointer(*const i64),
}
pub fn get_recursive_enum() -> Box<RecursiveEnum> {
let v1 = 1;
let enum1 = RecursiveEnum::Wrapper(Box::new(RecursiveEnum::Pointer(&v1))); // Source[rust/access-after-lifetime-ended]=v1
let mut ref1 = &enum1;
while let RecursiveEnum::Wrapper(inner) = ref1 {
println!(" wrapper");
ref1 = &inner;
}
if let RecursiveEnum::Pointer(ptr) = ref1 {
let v2: i64 = unsafe { **ptr }; // GOOD
println!(" v2 = {v2}");
}
return Box::new(enum1);
} // (v1 goes out of scope, thus the contained pointer is dangling)
pub fn test_recursive_enums() {
let enum1 = *get_recursive_enum();
let mut ref1 = &enum1;
while let RecursiveEnum::Wrapper(inner) = ref1 {
println!(" wrapper");
ref1 = &inner;
}
if let RecursiveEnum::Pointer(ptr) = ref1 {
let v3: i64 = unsafe { **ptr }; // Alert[rust/access-after-lifetime-ended]=v1
println!(" v3 = {v3} (!)"); // corrupt in practice
}
}
// --- std::ptr ---
#[derive(Debug)]
struct MyPair {
a: i64,
b: i64
}
impl Drop for MyPair {
fn drop(&mut self) {
println!(" drop MyPair '{} {}'", self.a, self.b);
self.a = -1;
self.b = -1;
}
}
pub fn test_ptr_to_struct(mode: i32) {
let p1: *mut MyPair;
let p2: *const i64;
let p3: *mut i64;
{
let mut my_pair = MyPair { a: 1, b: 2};
p1 = std::ptr::addr_of_mut!(my_pair); // $ Source[rust/access-after-lifetime-ended]=my_pair
p2 = std::ptr::addr_of!(my_pair.a); // $ MISSING: Source[rust/access-after-lifetime-ended]=my_pair_a
p3 = std::ptr::addr_of_mut!(my_pair.b); // $ MISSING: Source[rust/access-after-lifetime-ended]=my_pair_b
unsafe {
let v1 = (*p1).a; // GOOD
println!(" v1 = {v1}");
let v2 = (*p1).b; // GOOD
println!(" v2 = {v2}");
let v3 = *p2; // GOOD
let v4 = *p3; // GOOD
println!(" v3 = {v3}");
println!(" v4 = {v4}");
(*p1).a = 3; // GOOD
*p3 = 4; // GOOD
(*p1).b = 5; // GOOD
}
}; // my_pair goes out of scope, thus p1, p2, p3 are dangling
use_the_stack();
unsafe {
match mode {
0 => {
// read
let v5 = (*p1).a; // $ Alert[rust/access-after-lifetime-ended]=my_pair
println!(" v5 = {v5} (!)"); // dropped in practice
},
220 => {
// another read
let v6 = (*p1).b; // $ Alert[rust/access-after-lifetime-ended]=my_pair
println!(" v6 = {v6} (!)"); // dropped in practice
},
221 => {
// more reads
let v7 = *p2; // $ MISSING: Alert
let v8 = *p3; // $ MISSING: Alert
println!(" v7 = {v7} (!)"); // dropped in practice
println!(" v8 = {v8} (!)"); // dropped in practice
},
222 => {
// writes
(*p1).a = 6; // $ Alert[rust/access-after-lifetime-ended]=my_pair
*p3 = 7; // $ MISSING: Alert
},
223 => {
// another write
(*p1).b = 8; // $ Alert[rust/access-after-lifetime-ended]=my_pair
},
_ => {}
}
}
}
fn get_ptr_from_ref(val: i32) -> *const i32 {
let my_val = val;
let r1: &i32 = &my_val; // $ Source[rust/access-after-lifetime-ended]=my_val
let p1: *const i32 = std::ptr::from_ref(r1);
unsafe {
let v1 = *p1; // GOOD
println!(" v1 = {v1}");
}
return p1;
} // (returned pointer becomes dangling)
pub fn test_ptr_from_ref() {
let p1 = get_ptr_from_ref(1);
use_the_stack();
unsafe {
let v2 = *p1; // $ Alert[rust/access-after-lifetime-ended]=my_val
let v3 = *get_ptr_from_ref(2); // $ Alert[rust/access-after-lifetime-ended]=my_val
println!(" v2 = {v2} (!)"); // corrupt in practice
println!(" v3 = {v3} (!)");
}
}
// --- std::rc (reference counting pointer) ---
pub fn test_rc() {
let p1: *const i64;
let p2: *const i64;
{
let rc1: std::rc::Rc<i64> = std::rc::Rc::new(1);
p1 = std::rc::Rc::<i64>::as_ptr(&rc1);
{
let rc2: std::rc::Rc<i64> = std::rc::Rc::clone(&rc1);
p2 = std::rc::Rc::<i64>::as_ptr(&rc2);
unsafe {
let v1 = *p1; // GOOD
let v2 = *p2; // GOOD
println!(" v1 = {v1}");
println!(" v2 = {v2}");
}
} // rc2 goes out of scope, but the reference count is still 1 so the pointer remains valid
unsafe {
let v3 = *p1; // GOOD
let v4 = *p2; // GOOD
println!(" v3 = {v3}");
println!(" v4 = {v4}");
}
} // rc1 goes out of scope, the reference count is 0, so p1, p2 are dangling
unsafe {
let v5 = *p1; // $ MISSING: Alert
let v6 = *p2; // $ MISSING: Alert
println!(" v5 = {v5} (!)"); // corrupt in practice
println!(" v6 = {v6} (!)"); // corrupt in practice
}
// note: simialar things are likely possible with Ref, RefMut, RefCell,
// Vec and others.
}
// --- closures ---
fn get_closure(p3: *const i64, p4: *const i64) -> impl FnOnce() {
let my_local1: i64 = 1;
let my_local2: i64 = 2;
let p1: *const i64 = &my_local1; // $ MISSING: Source[rust/access-after-lifetime-ended]=local1
return move || { // captures `my_local2`, `p1`, `p3`, `p4` by value (due to `move`)
let p2: *const i64 = &my_local2;
unsafe {
let v1 = *p1; // $ MISSING: Alert[rust/access-after-lifetime-ended]=local1
let v2 = *p2; // GOOD
let v3 = *p3; // GOOD
let v4 = *p4; // $ MISSING: Alert[rust/access-after-lifetime-ended]=local4
println!(" v1 = {v1} (!)"); // corrupt in practice
println!(" v2 = {v2}");
println!(" v3 = {v3}");
println!(" v4 = {v4} (!)");
}
};
} // (`my_local1` goes out of scope, thus `p1` is dangling)
fn with_closure(ptr: *const i64, closure: fn(*const i64, *const i64)) {
let my_local5: i64 = 5;
closure(ptr,
&my_local5);
}
pub fn test_closures() {
let closure;
let my_local3: i64 = 3;
{
let my_local4: i64 = 4;
closure = get_closure( &my_local3,
&my_local4); // $ MISSING: Source[rust/access-after-lifetime-ended]=local4
} // (`my_local4` goes out of scope, so `p4` is dangling)
use_the_stack();
closure();
with_closure(&my_local3, |p1, p2| {
unsafe {
let v5 = *p1; // GOOD
let v6 = *p2; // $ GOOD
println!(" v5 = {v5}");
println!(" v6 = {v6}");
}
});
}
// --- async ---
fn get_async_closure(p3: *const i64, p4: *const i64) -> impl std::future::Future<Output = ()> {
let my_local1: i64 = 1;
let my_local2: i64 = 2;
let p1: *const i64 = &my_local1;
return async move { // captures `my_local2`, `p1`, `p3`, `p4` by value (due to `move`)
let p2: *const i64 = &my_local2;
unsafe {
let v1 = *p1; // $ MISSING: Alert
let v2 = *p2; // GOOD
let v3 = *p3; // GOOD
let v4 = *p4; // $ MISSING: Alert
println!(" v1 = {v1} (!)"); // corrupt in practice
println!(" v2 = {v2}");
println!(" v3 = {v3}");
println!(" v4 = {v4} (!)");
}
};
} // (`my_local1` goes out of scope, thus `p1` is dangling)
pub fn test_async() {
let async_closure;
let my_local3: i64 = 3;
{
let my_local4: i64 = 4;
async_closure = get_async_closure(&my_local3,
&my_local4);
} // (`my_local4` goes out of scope, so `p4` is dangling)
use_the_stack();
futures::executor::block_on(async_closure);
}
// --- lifetime annotations ---
fn select_str<'a>(cond: bool, a: &'a str, b: &'a str) -> &'a str {
if cond { a } else { b }
}
struct MyRefStr<'a> {
ref_str: &'a str,
}
pub fn test_lifetime_annotations() {
let str1: *const str;
{
let foo = String::from("foo");
let bar = String::from("bar");
str1 = select_str(true, foo.as_str(), bar.as_str());
unsafe {
let v1 = &*str1; // GOOD
println!(" v1 = {v1}");
}
} // (`foo`, `bar` go out of scope, the return value of `select_str` has the same lifetime, thus `str1` is dangling)
unsafe {
let v2 = &*str1; // $ MISSING: Alert
println!(" v2 = {v2} (!)"); // corrupt in practice
}
let my_ref;
let str2: *const str;
{
let baz = String::from("baz");
my_ref = MyRefStr { ref_str: baz.as_str() };
str2 = &*my_ref.ref_str;
unsafe {
let v3 = &*str2; // GOOD
println!(" v3 = {v3}");
}
} // (`baz` goes out of scope, `ref_str` has the same lifetime, thus `str2` is dangling)
use_the_stack();
unsafe {
let v4 = &*str2; // $ MISSING: Alert
println!(" v4 = {v4} (!)"); // corrupt in practice
}
}
// --- implicit dereferences ---
pub fn test_implicit_derefs() {
let ref1;
{
let str2;
{
let str1 = "bar";
str2 = "foo".to_string() + &str1;
ref1 = &raw const str2; // $ Source[rust/access-after-lifetime-ended]=str2
} // (str1 goes out of scope, but it's been copied into str2)
unsafe {
let v1 = &*ref1;
println!(" v1 = {v1}");
}
} // (str2 goes out of scope, thus ref1 is dangling)
use_the_stack();
unsafe {
let v2 = &*ref1; // $ Alert[rust/access-after-lifetime-ended]=str2
println!(" v2 = {v2} (!)"); // corrupt in practice
}
}
// --- members ---
struct MyType {
value: i64,
}
impl MyType {
fn test(&self) {
let r1 = unsafe {
let v1 = &self;
&v1.value
};
let (r2, r3) = unsafe {
let v2 = &self;
(&v2.value,
&self.value)
};
use_the_stack();
let v1 = *r1;
let v2 = *r2;
let v3 = *r3;
println!(" v1 = {v1}");
println!(" v2 = {v2}");
println!(" v3 = {v3}");
}
}
pub fn test_members() {
let mt = MyType { value: 1 };
mt.test();
}
// --- enum members ---
struct MyValue2 {
value: i64
}
enum MyEnum3 {
Value(MyValue2),
}
impl MyEnum3 {
pub fn test_match(&self) -> &i64 {
let r1 = match self {
MyEnum3::Value(v2) => &v2.value,
};
r1
}
}
pub fn test_enum_members() {
let v1 = MyValue2 { value: 1 };
let e1 = MyEnum3::Value(v1);
let r1 = e1.test_match();
use_the_stack();
let v3 = *r1;
println!(" v3 = {v3}");
}
// --- macros ---
macro_rules! my_macro1 {
() => {
let ptr: *const i64;
{
let val: i64 = 1;
ptr = &val;
}
unsafe {
let v = *ptr;
println!(" v = {v}");
}
}
}
macro_rules! my_macro2 {
() => {
{
let val: i64 = 1;
let ptr: *const i64 = &val;
ptr
}
}
}
pub fn test_macros() {
my_macro1!();
my_macro1!();
let ptr = my_macro2!();
unsafe {
let v = *ptr;
println!(" v = {v}");
}
}
// --- unsafe function ---
fn get_local_for_unsafe_function() -> *const f64 {
let my_local10: f64 = 1.23;
return &my_local10; // $ Source[rust/access-after-lifetime-ended]=local10
} // (return value immediately becomes dangling)
pub unsafe fn test_unsafe_function() {
let p1 = get_local_for_unsafe_function();
use_the_stack();
let v1 = *p1; // $ Alert[rust/access-after-lifetime-ended]=local10
println!(" v1 = {v1} (!)"); // corrupt in practice
}
// --- examples from qhelp ---
fn get_pointer() -> *const i64 {
let val = 123;
return &val; // $ Source[rust/access-after-lifetime-ended]=val
} // lifetime of `val` ends here, the pointer becomes dangling
pub fn test_lifetimes_example_bad() {
let ptr = get_pointer();
let dereferenced_ptr;
use_the_stack();
unsafe {
dereferenced_ptr = *ptr; // $ Alert[rust/access-after-lifetime-ended]=val
}
println!(" val = {dereferenced_ptr} (!)"); // corrupt in practice
}
fn get_box() -> Box<i64> {
let val = 123;
return Box::new(val);
}
pub fn test_lifetimes_example_good() {
let ptr = get_box();
let dereferenced_ptr;
use_the_stack();
dereferenced_ptr = *ptr; // GOOD
println!(" val = {dereferenced_ptr}");
}