fix segmentation fault when `datetime` module is invalid

newsfragments/3818.fixed.md

@@ -0,0 +1 @@
+Fix segmentation fault using `datetime` types when an invalid `datetime` module is on sys.path.

src/types/datetime.rs

@@ -23,21 +23,27 @@ use crate::ffi_ptr_ext::FfiPtrExt;
 use crate::instance::PyNativeType;
 use crate::types::any::PyAnyMethods;
 use crate::types::PyTuple;
-use crate::{Bound, IntoPy, Py, PyAny, Python};
+use crate::{Bound, IntoPy, Py, PyAny, PyErr, Python};
 use std::os::raw::c_int;
 #[cfg(feature = "chrono")]
 use std::ptr;
 
-fn ensure_datetime_api(_py: Python<'_>) -> &'static PyDateTime_CAPI {
-    unsafe {
-        if pyo3_ffi::PyDateTimeAPI().is_null() {
-            PyDateTime_IMPORT()
+fn ensure_datetime_api(py: Python<'_>) -> PyResult<&'static PyDateTime_CAPI> {
+    if let Some(api) = unsafe { pyo3_ffi::PyDateTimeAPI().as_ref() } {
+        Ok(api)
+    } else {
+        unsafe {
+            PyDateTime_IMPORT();
+            pyo3_ffi::PyDateTimeAPI().as_ref()
         }
-
-        &*pyo3_ffi::PyDateTimeAPI()
+        .ok_or_else(|| PyErr::fetch(py))
     }
 }
 
+fn expect_datetime_api(py: Python<'_>) -> &'static PyDateTime_CAPI {
+    ensure_datetime_api(py).expect("failed to import `datetime` C API")
+}
+
 // Type Check macros
 //
 // These are bindings around the C API typecheck macros, all of them return
@@ -189,7 +195,7 @@ pub struct PyDate(PyAny);
 pyobject_native_type!(
     PyDate,
     crate::ffi::PyDateTime_Date,
-    |py| ensure_datetime_api(py).DateType,
+    |py| expect_datetime_api(py).DateType,
     #module=Some("datetime"),
     #checkfunction=PyDate_Check
 );
@@ -197,13 +203,9 @@ pyobject_native_type!(
 impl PyDate {
     /// Creates a new `datetime.date`.
     pub fn new(py: Python<'_>, year: i32, month: u8, day: u8) -> PyResult<&PyDate> {
+        let api = ensure_datetime_api(py)?;
         unsafe {
-            let ptr = (ensure_datetime_api(py).Date_FromDate)(
-                year,
-                c_int::from(month),
-                c_int::from(day),
-                ensure_datetime_api(py).DateType,
-            );
+            let ptr = (api.Date_FromDate)(year, c_int::from(month), c_int::from(day), api.DateType);
             py.from_owned_ptr_or_err(ptr)
         }
     }
@@ -215,7 +217,7 @@ impl PyDate {
         let time_tuple = PyTuple::new_bound(py, [timestamp]);
 
         // safety ensure that the API is loaded
-        let _api = ensure_datetime_api(py);
+        let _api = ensure_datetime_api(py)?;
 
         unsafe {
             let ptr = PyDate_FromTimestamp(time_tuple.as_ptr());
@@ -258,7 +260,7 @@ pub struct PyDateTime(PyAny);
 pyobject_native_type!(
     PyDateTime,
     crate::ffi::PyDateTime_DateTime,
-    |py| ensure_datetime_api(py).DateTimeType,
+    |py| expect_datetime_api(py).DateTimeType,
     #module=Some("datetime"),
     #checkfunction=PyDateTime_Check
 );
@@ -277,7 +279,7 @@ impl PyDateTime {
         microsecond: u32,
         tzinfo: Option<&PyTzInfo>,
     ) -> PyResult<&'p PyDateTime> {
-        let api = ensure_datetime_api(py);
+        let api = ensure_datetime_api(py)?;
         unsafe {
             let ptr = (api.DateTime_FromDateAndTime)(
                 year,
@@ -314,7 +316,7 @@ impl PyDateTime {
         tzinfo: Option<&PyTzInfo>,
         fold: bool,
     ) -> PyResult<&'p PyDateTime> {
-        let api = ensure_datetime_api(py);
+        let api = ensure_datetime_api(py)?;
         unsafe {
             let ptr = (api.DateTime_FromDateAndTimeAndFold)(
                 year,
@@ -343,7 +345,7 @@ impl PyDateTime {
         let args: Py<PyTuple> = (timestamp, tzinfo).into_py(py);
 
         // safety ensure API is loaded
-        let _api = ensure_datetime_api(py);
+        let _api = ensure_datetime_api(py)?;
 
         unsafe {
             let ptr = PyDateTime_FromTimestamp(args.as_ptr());
@@ -455,7 +457,7 @@ pub struct PyTime(PyAny);
 pyobject_native_type!(
     PyTime,
     crate::ffi::PyDateTime_Time,
-    |py| ensure_datetime_api(py).TimeType,
+    |py| expect_datetime_api(py).TimeType,
     #module=Some("datetime"),
     #checkfunction=PyTime_Check
 );
@@ -470,7 +472,7 @@ impl PyTime {
         microsecond: u32,
         tzinfo: Option<&PyTzInfo>,
     ) -> PyResult<&'p PyTime> {
-        let api = ensure_datetime_api(py);
+        let api = ensure_datetime_api(py)?;
         unsafe {
             let ptr = (api.Time_FromTime)(
                 c_int::from(hour),
@@ -494,7 +496,7 @@ impl PyTime {
         tzinfo: Option<&PyTzInfo>,
         fold: bool,
     ) -> PyResult<&'p PyTime> {
-        let api = ensure_datetime_api(py);
+        let api = ensure_datetime_api(py)?;
         unsafe {
             let ptr = (api.Time_FromTimeAndFold)(
                 c_int::from(hour),
@@ -589,14 +591,14 @@ pub struct PyTzInfo(PyAny);
 pyobject_native_type!(
     PyTzInfo,
     crate::ffi::PyObject,
-    |py| ensure_datetime_api(py).TZInfoType,
+    |py| expect_datetime_api(py).TZInfoType,
     #module=Some("datetime"),
     #checkfunction=PyTZInfo_Check
 );
 
 /// Equivalent to `datetime.timezone.utc`
 pub fn timezone_utc(py: Python<'_>) -> &PyTzInfo {
-    unsafe { &*(ensure_datetime_api(py).TimeZone_UTC as *const PyTzInfo) }
+    unsafe { &*(expect_datetime_api(py).TimeZone_UTC as *const PyTzInfo) }
 }
 
 /// Equivalent to `datetime.timezone` constructor
@@ -604,7 +606,7 @@ pub fn timezone_utc(py: Python<'_>) -> &PyTzInfo {
 /// Only used internally
 #[cfg(feature = "chrono")]
 pub fn timezone_from_offset<'a>(py: Python<'a>, offset: &PyDelta) -> PyResult<&'a PyTzInfo> {
-    let api = ensure_datetime_api(py);
+    let api = ensure_datetime_api(py)?;
     unsafe {
         let ptr = (api.TimeZone_FromTimeZone)(offset.as_ptr(), ptr::null_mut());
         py.from_owned_ptr_or_err(ptr)
@@ -617,7 +619,7 @@ pub struct PyDelta(PyAny);
 pyobject_native_type!(
     PyDelta,
     crate::ffi::PyDateTime_Delta,
-    |py| ensure_datetime_api(py).DeltaType,
+    |py| expect_datetime_api(py).DeltaType,
     #module=Some("datetime"),
     #checkfunction=PyDelta_Check
 );
@@ -631,7 +633,7 @@ impl PyDelta {
         microseconds: i32,
         normalize: bool,
     ) -> PyResult<&PyDelta> {
-        let api = ensure_datetime_api(py);
+        let api = ensure_datetime_api(py)?;
         unsafe {
             let ptr = (api.Delta_FromDelta)(
                 days as c_int,

tests/test_datetime_import.rs

@@ -0,0 +1,26 @@
+#![cfg(not(Py_LIMITED_API))]
+
+use pyo3::{types::PyDate, Python};
+
+#[test]
+#[should_panic(expected = "module 'datetime' has no attribute 'datetime_CAPI'")]
+fn test_bad_datetime_module_panic() {
+    // Create an empty temporary directory
+    // with an empty "datetime" module which we'll put on the sys.path
+    let tmpdir = std::env::temp_dir();
+    let tmpdir = tmpdir.join("pyo3_test_date_check");
+    let _ = std::fs::remove_dir_all(&tmpdir);
+    std::fs::create_dir(&tmpdir).unwrap();
+    std::fs::File::create(tmpdir.join("datetime.py")).unwrap();
+
+    Python::with_gil(|py: Python<'_>| {
+        let sys = py.import("sys").unwrap();
+        sys.getattr("path")
+            .unwrap()
+            .call_method1("insert", (0, tmpdir))
+            .unwrap();
+
+        // This should panic because the "datetime" module is empty
+        PyDate::new(py, 2018, 1, 1).unwrap();
+    });
+}