Files
wasmtime/tests/all/pooling_allocator.rs
Peter Huene ef17a36852 Port fix for CVE-2022-23636 to main. (#3818)
* Port fix for `CVE-2022-23636` to `main`.

This commit ports the fix for `CVE-2022-23636` to `main`, but performs a
refactoring that makes it unnecessary for the instance itself to track if it
has been initialized; such a change was not targeted enough for a security
patch.

The pooling allocator will now only initialize an instance if all of its
associated resource creation succeeds. If the resource creation fails, no
instance is dropped as none was initialized.

Also updates `RELEASES.md` to include the related patch releases.

* Add `Instance::new_at` to fully initialize an instance.

Added `Instance::new_at` to fully initialize an instance at a given address.

This will hopefully prevent the possibility that an `Instance` structure
doesn't have an initialized `VMContext` when it is dropped.
2022-02-16 17:51:14 -06:00

609 lines
19 KiB
Rust

use super::skip_pooling_allocator_tests;
use anyhow::Result;
use wasmtime::*;
#[test]
fn successful_instantiation() -> Result<()> {
let mut config = Config::new();
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: ModuleLimits {
memory_pages: 1,
table_elements: 10,
..Default::default()
},
instance_limits: InstanceLimits { count: 1 },
});
config.dynamic_memory_guard_size(0);
config.static_memory_guard_size(0);
config.static_memory_maximum_size(65536);
let engine = Engine::new(&config)?;
let module = Module::new(&engine, r#"(module (memory 1) (table 10 funcref))"#)?;
// Module should instantiate
let mut store = Store::new(&engine, ());
Instance::new(&mut store, &module, &[])?;
Ok(())
}
#[test]
fn memory_limit() -> Result<()> {
let mut config = Config::new();
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: ModuleLimits {
memory_pages: 3,
table_elements: 10,
..Default::default()
},
instance_limits: InstanceLimits { count: 1 },
});
config.dynamic_memory_guard_size(0);
config.static_memory_guard_size(65536);
config.static_memory_maximum_size(3 * 65536);
let engine = Engine::new(&config)?;
// Module should fail to validate because the minimum is greater than the configured limit
match Module::new(&engine, r#"(module (memory 4))"#) {
Ok(_) => panic!("module compilation should fail"),
Err(e) => assert_eq!(
e.to_string(),
"memory index 0 has a minimum page size of 4 which exceeds the limit of 3"
),
}
let module = Module::new(
&engine,
r#"(module (memory (export "m") 0) (func (export "f") (result i32) (memory.grow (i32.const 1))))"#,
)?;
// Instantiate the module and grow the memory via the `f` function
{
let mut store = Store::new(&engine, ());
let instance = Instance::new(&mut store, &module, &[])?;
let f = instance.get_typed_func::<(), i32, _>(&mut store, "f")?;
assert_eq!(f.call(&mut store, ()).expect("function should not trap"), 0);
assert_eq!(f.call(&mut store, ()).expect("function should not trap"), 1);
assert_eq!(f.call(&mut store, ()).expect("function should not trap"), 2);
assert_eq!(
f.call(&mut store, ()).expect("function should not trap"),
-1
);
assert_eq!(
f.call(&mut store, ()).expect("function should not trap"),
-1
);
}
// Instantiate the module and grow the memory via the Wasmtime API
let mut store = Store::new(&engine, ());
let instance = Instance::new(&mut store, &module, &[])?;
let memory = instance.get_memory(&mut store, "m").unwrap();
assert_eq!(memory.size(&store), 0);
assert_eq!(memory.grow(&mut store, 1).expect("memory should grow"), 0);
assert_eq!(memory.size(&store), 1);
assert_eq!(memory.grow(&mut store, 1).expect("memory should grow"), 1);
assert_eq!(memory.size(&store), 2);
assert_eq!(memory.grow(&mut store, 1).expect("memory should grow"), 2);
assert_eq!(memory.size(&store), 3);
assert!(memory.grow(&mut store, 1).is_err());
Ok(())
}
#[test]
fn memory_init() -> Result<()> {
let mut config = Config::new();
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: ModuleLimits {
memory_pages: 2,
table_elements: 0,
..Default::default()
},
instance_limits: InstanceLimits {
count: 1,
..Default::default()
},
});
let engine = Engine::new(&config)?;
let module = Module::new(
&engine,
r#"(module (memory (export "m") 2) (data (i32.const 65530) "this data spans multiple pages") (data (i32.const 10) "hello world"))"#,
)?;
let mut store = Store::new(&engine, ());
let instance = Instance::new(&mut store, &module, &[])?;
let memory = instance.get_memory(&mut store, "m").unwrap();
assert_eq!(
&memory.data(&store)[65530..65560],
b"this data spans multiple pages"
);
assert_eq!(&memory.data(&store)[10..21], b"hello world");
Ok(())
}
#[test]
fn memory_guard_page_trap() -> Result<()> {
let mut config = Config::new();
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: ModuleLimits {
memory_pages: 2,
table_elements: 0,
..Default::default()
},
instance_limits: InstanceLimits {
count: 1,
..Default::default()
},
});
let engine = Engine::new(&config)?;
let module = Module::new(
&engine,
r#"(module (memory (export "m") 0) (func (export "f") (param i32) local.get 0 i32.load drop))"#,
)?;
// Instantiate the module and check for out of bounds trap
for _ in 0..10 {
let mut store = Store::new(&engine, ());
let instance = Instance::new(&mut store, &module, &[])?;
let m = instance.get_memory(&mut store, "m").unwrap();
let f = instance.get_typed_func::<i32, (), _>(&mut store, "f")?;
let trap = f.call(&mut store, 0).expect_err("function should trap");
assert!(trap.to_string().contains("out of bounds"));
let trap = f.call(&mut store, 1).expect_err("function should trap");
assert!(trap.to_string().contains("out of bounds"));
m.grow(&mut store, 1).expect("memory should grow");
f.call(&mut store, 0).expect("function should not trap");
let trap = f.call(&mut store, 65536).expect_err("function should trap");
assert!(trap.to_string().contains("out of bounds"));
let trap = f.call(&mut store, 65537).expect_err("function should trap");
assert!(trap.to_string().contains("out of bounds"));
m.grow(&mut store, 1).expect("memory should grow");
f.call(&mut store, 65536).expect("function should not trap");
m.grow(&mut store, 1)
.expect_err("memory should be at the limit");
}
Ok(())
}
#[test]
fn memory_zeroed() -> Result<()> {
if skip_pooling_allocator_tests() {
return Ok(());
}
let mut config = Config::new();
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: ModuleLimits {
memory_pages: 1,
table_elements: 0,
..Default::default()
},
instance_limits: InstanceLimits { count: 1 },
});
config.dynamic_memory_guard_size(0);
config.static_memory_guard_size(0);
config.static_memory_maximum_size(65536);
let engine = Engine::new(&config)?;
let module = Module::new(&engine, r#"(module (memory (export "m") 1))"#)?;
// Instantiate the module repeatedly after writing data to the entire memory
for _ in 0..10 {
let mut store = Store::new(&engine, ());
let instance = Instance::new(&mut store, &module, &[])?;
let memory = instance.get_memory(&mut store, "m").unwrap();
assert_eq!(memory.size(&store,), 1);
assert_eq!(memory.data_size(&store), 65536);
let ptr = memory.data_mut(&mut store).as_mut_ptr();
unsafe {
for i in 0..8192 {
assert_eq!(*ptr.cast::<u64>().offset(i), 0);
}
std::ptr::write_bytes(ptr, 0xFE, memory.data_size(&store));
}
}
Ok(())
}
#[test]
fn table_limit() -> Result<()> {
const TABLE_ELEMENTS: u32 = 10;
let mut config = Config::new();
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: ModuleLimits {
memory_pages: 1,
table_elements: TABLE_ELEMENTS,
..Default::default()
},
instance_limits: InstanceLimits { count: 1 },
});
config.dynamic_memory_guard_size(0);
config.static_memory_guard_size(0);
config.static_memory_maximum_size(65536);
let engine = Engine::new(&config)?;
// Module should fail to validate because the minimum is greater than the configured limit
match Module::new(&engine, r#"(module (table 31 funcref))"#) {
Ok(_) => panic!("module compilation should fail"),
Err(e) => assert_eq!(
e.to_string(),
"table index 0 has a minimum element size of 31 which exceeds the limit of 10"
),
}
let module = Module::new(
&engine,
r#"(module (table (export "t") 0 funcref) (func (export "f") (result i32) (table.grow (ref.null func) (i32.const 1))))"#,
)?;
// Instantiate the module and grow the table via the `f` function
{
let mut store = Store::new(&engine, ());
let instance = Instance::new(&mut store, &module, &[])?;
let f = instance.get_typed_func::<(), i32, _>(&mut store, "f")?;
for i in 0..TABLE_ELEMENTS {
assert_eq!(
f.call(&mut store, ()).expect("function should not trap"),
i as i32
);
}
assert_eq!(
f.call(&mut store, ()).expect("function should not trap"),
-1
);
assert_eq!(
f.call(&mut store, ()).expect("function should not trap"),
-1
);
}
// Instantiate the module and grow the table via the Wasmtime API
let mut store = Store::new(&engine, ());
let instance = Instance::new(&mut store, &module, &[])?;
let table = instance.get_table(&mut store, "t").unwrap();
for i in 0..TABLE_ELEMENTS {
assert_eq!(table.size(&store), i);
assert_eq!(
table
.grow(&mut store, 1, Val::FuncRef(None))
.expect("table should grow"),
i
);
}
assert_eq!(table.size(&store), TABLE_ELEMENTS);
assert!(table.grow(&mut store, 1, Val::FuncRef(None)).is_err());
Ok(())
}
#[test]
fn table_init() -> Result<()> {
let mut config = Config::new();
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: ModuleLimits {
memory_pages: 0,
table_elements: 6,
..Default::default()
},
instance_limits: InstanceLimits {
count: 1,
..Default::default()
},
});
let engine = Engine::new(&config)?;
let module = Module::new(
&engine,
r#"(module (table (export "t") 6 funcref) (elem (i32.const 1) 1 2 3 4) (elem (i32.const 0) 0) (func) (func (param i32)) (func (param i32 i32)) (func (param i32 i32 i32)) (func (param i32 i32 i32 i32)))"#,
)?;
let mut store = Store::new(&engine, ());
let instance = Instance::new(&mut store, &module, &[])?;
let table = instance.get_table(&mut store, "t").unwrap();
for i in 0..5 {
let v = table.get(&mut store, i).expect("table should have entry");
let f = v
.funcref()
.expect("expected funcref")
.expect("expected non-null value");
assert_eq!(f.ty(&store).params().len(), i as usize);
}
assert!(
table
.get(&mut store, 5)
.expect("table should have entry")
.funcref()
.expect("expected funcref")
.is_none(),
"funcref should be null"
);
Ok(())
}
#[test]
fn table_zeroed() -> Result<()> {
if skip_pooling_allocator_tests() {
return Ok(());
}
let mut config = Config::new();
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: ModuleLimits {
memory_pages: 1,
table_elements: 10,
..Default::default()
},
instance_limits: InstanceLimits { count: 1 },
});
config.dynamic_memory_guard_size(0);
config.static_memory_guard_size(0);
config.static_memory_maximum_size(65536);
let engine = Engine::new(&config)?;
let module = Module::new(&engine, r#"(module (table (export "t") 10 funcref))"#)?;
// Instantiate the module repeatedly after filling table elements
for _ in 0..10 {
let mut store = Store::new(&engine, ());
let instance = Instance::new(&mut store, &module, &[])?;
let table = instance.get_table(&mut store, "t").unwrap();
let f = Func::wrap(&mut store, || {});
assert_eq!(table.size(&store), 10);
for i in 0..10 {
match table.get(&mut store, i).unwrap() {
Val::FuncRef(r) => assert!(r.is_none()),
_ => panic!("expected a funcref"),
}
table
.set(&mut store, i, Val::FuncRef(Some(f.clone())))
.unwrap();
}
}
Ok(())
}
#[test]
fn instantiation_limit() -> Result<()> {
const INSTANCE_LIMIT: u32 = 10;
let mut config = Config::new();
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: ModuleLimits {
memory_pages: 1,
table_elements: 10,
..Default::default()
},
instance_limits: InstanceLimits {
count: INSTANCE_LIMIT,
},
});
config.dynamic_memory_guard_size(0);
config.static_memory_guard_size(0);
config.static_memory_maximum_size(65536);
let engine = Engine::new(&config)?;
let module = Module::new(&engine, r#"(module)"#)?;
// Instantiate to the limit
{
let mut store = Store::new(&engine, ());
for _ in 0..INSTANCE_LIMIT {
Instance::new(&mut store, &module, &[])?;
}
match Instance::new(&mut store, &module, &[]) {
Ok(_) => panic!("instantiation should fail"),
Err(e) => assert_eq!(
e.to_string(),
format!(
"Limit of {} concurrent instances has been reached",
INSTANCE_LIMIT
)
),
}
}
// With the above store dropped, ensure instantiations can be made
let mut store = Store::new(&engine, ());
for _ in 0..INSTANCE_LIMIT {
Instance::new(&mut store, &module, &[])?;
}
Ok(())
}
#[test]
fn preserve_data_segments() -> Result<()> {
let mut config = Config::new();
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: ModuleLimits {
memory_pages: 1,
table_elements: 10,
..Default::default()
},
instance_limits: InstanceLimits { count: 2 },
});
let engine = Engine::new(&config)?;
let m = Module::new(
&engine,
r#"
(module
(memory (export "mem") 1 1)
(data (i32.const 0) "foo"))
"#,
)?;
let mut store = Store::new(&engine, ());
let i = Instance::new(&mut store, &m, &[])?;
// Drop the module. This should *not* drop the actual data referenced by the
// module, especially when uffd is enabled. If uffd is enabled we'll lazily
// fault in the memory of the module, which means it better still be alive
// after we drop this.
drop(m);
// Spray some stuff on the heap. If wasm data lived on the heap this should
// paper over things and help us catch use-after-free here if it would
// otherwise happen.
let mut strings = Vec::new();
for _ in 0..1000 {
let mut string = String::new();
for _ in 0..1000 {
string.push('g');
}
strings.push(string);
}
drop(strings);
let mem = i.get_memory(&mut store, "mem").unwrap();
// This will segfault with uffd enabled, and then the uffd will lazily
// initialize the memory. Hopefully it's still `foo`!
assert!(mem.data(&store).starts_with(b"foo"));
Ok(())
}
#[test]
fn multi_memory_with_imported_memories() -> Result<()> {
// This test checks that the base address for the defined memory is correct for the instance
// despite the presence of an imported memory.
let mut config = Config::new();
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: ModuleLimits {
memory_pages: 1,
imported_memories: 1,
memories: 1,
..Default::default()
},
instance_limits: InstanceLimits { count: 1 },
});
config.wasm_multi_memory(true);
let engine = Engine::new(&config)?;
let module = Module::new(
&engine,
r#"(module (import "" "m1" (memory 0)) (memory (export "m2") 1))"#,
)?;
let mut store = Store::new(&engine, ());
let m1 = Memory::new(&mut store, MemoryType::new(0, None))?;
let instance = Instance::new(&mut store, &module, &[m1.into()])?;
let m2 = instance.get_memory(&mut store, "m2").unwrap();
m2.data_mut(&mut store)[0] = 0x42;
assert_eq!(m2.data(&store)[0], 0x42);
Ok(())
}
#[test]
fn drop_externref_global_during_module_init() -> Result<()> {
struct Limiter;
impl ResourceLimiter for Limiter {
fn memory_growing(&mut self, _: usize, _: usize, _: Option<usize>) -> bool {
false
}
fn table_growing(&mut self, _: u32, _: u32, _: Option<u32>) -> bool {
false
}
}
let mut config = Config::new();
config.wasm_reference_types(true);
config.allocation_strategy(InstanceAllocationStrategy::Pooling {
strategy: PoolingAllocationStrategy::NextAvailable,
module_limits: Default::default(),
instance_limits: InstanceLimits { count: 1 },
});
let engine = Engine::new(&config)?;
let module = Module::new(
&engine,
r#"
(module
(global i32 (i32.const 1))
(global i32 (i32.const 2))
(global i32 (i32.const 3))
(global i32 (i32.const 4))
(global i32 (i32.const 5))
)
"#,
)?;
let mut store = Store::new(&engine, Limiter);
drop(Instance::new(&mut store, &module, &[])?);
drop(store);
let module = Module::new(
&engine,
r#"
(module
(memory 1)
(global (mut externref) (ref.null extern))
)
"#,
)?;
let mut store = Store::new(&engine, Limiter);
store.limiter(|s| s);
assert!(Instance::new(&mut store, &module, &[]).is_err());
Ok(())
}