From 05af96236192efb9dbfee40447add09f0ef878c2 Mon Sep 17 00:00:00 2001
From: 1fanwang <1fannnw@gmail.com>
Date: Wed, 23 Sep 2026 23:39:22 -0700
Subject: [PATCH 1/4] GH-51043: Reject null required PyArrow objects

Signed-off-by: 1fanwang <1fannnw@gmail.com>
---
 python/pyarrow/_dataset.pyx                   | 5 ++++-
 python/pyarrow/_parquet.pyx                   | 5 +++--
 python/pyarrow/array.pxi                      | 5 +++--
 python/pyarrow/tests/parquet/test_metadata.py | 6 ++++++
 python/pyarrow/tests/test_array.py            | 4 ++++
 python/pyarrow/tests/test_dataset.py          | 6 ++++++
 6 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/python/pyarrow/_dataset.pyx b/python/pyarrow/_dataset.pyx
index d40614a61fc0..e06fc6caf6c9 100644
--- a/python/pyarrow/_dataset.pyx
+++ b/python/pyarrow/_dataset.pyx
@@ -1121,7 +1121,8 @@ cdef class FileSystemDataset(Dataset):
     cdef:
         CFileSystemDataset* filesystem_dataset
 
-    def __init__(self, fragments, Schema schema, FileFormat format,
+    def __init__(self, fragments, Schema schema not None,
+                 FileFormat format not None,
                  FileSystem filesystem=None, root_partition=None):
         cdef:
             FileFragment fragment=None
@@ -1138,6 +1139,8 @@ cdef class FileSystemDataset(Dataset):
             )
 
         for fragment in fragments:
+            if fragment is None:
+                raise TypeError("Fragment must not be None")
             c_fragments.push_back(
                 static_pointer_cast[CFileFragment, CFragment](
                     fragment.unwrap()))
diff --git a/python/pyarrow/_parquet.pyx b/python/pyarrow/_parquet.pyx
index 2621c3bd6d61..a1e2b1ba3003 100644
--- a/python/pyarrow/_parquet.pyx
+++ b/python/pyarrow/_parquet.pyx
@@ -755,7 +755,8 @@ cdef class SortingColumn:
         self.nulls_first = nulls_first
 
     @classmethod
-    def from_ordering(cls, Schema schema, sort_keys, null_placement='at_end'):
+    def from_ordering(cls, Schema schema not None, sort_keys,
+                      null_placement='at_end'):
         """
         Create a tuple of SortingColumn objects from the same arguments as
         :class:`pyarrow.compute.SortOptions`.
@@ -816,7 +817,7 @@ cdef class SortingColumn:
         return tuple(sorting_columns)
 
     @staticmethod
-    def to_ordering(Schema schema, sorting_columns):
+    def to_ordering(Schema schema not None, sorting_columns):
         """
         Convert a tuple of SortingColumn objects to the same format as
         :class:`pyarrow.compute.SortOptions`.
diff --git a/python/pyarrow/array.pxi b/python/pyarrow/array.pxi
index 865d2079fc0e..9de37b807909 100644
--- a/python/pyarrow/array.pxi
+++ b/python/pyarrow/array.pxi
@@ -4351,8 +4351,9 @@ cdef class DictionaryArray(Array):
         return self._indices
 
     @staticmethod
-    def from_buffers(DataType type, int64_t length, buffers, Array dictionary,
-                     int64_t null_count=-1, int64_t offset=0):
+    def from_buffers(DataType type not None, int64_t length, buffers,
+                     Array dictionary, int64_t null_count=-1,
+                     int64_t offset=0):
         """
         Construct a DictionaryArray from buffers.
 
diff --git a/python/pyarrow/tests/parquet/test_metadata.py b/python/pyarrow/tests/parquet/test_metadata.py
index 9eee70b125e5..eafffd3436e0 100644
--- a/python/pyarrow/tests/parquet/test_metadata.py
+++ b/python/pyarrow/tests/parquet/test_metadata.py
@@ -351,6 +351,12 @@ def test_parquet_sorting_column():
     with pytest.raises(ValueError):
         pq.SortingColumn.from_ordering(schema, (("a", "not a valid sort order")))
 
+    with pytest.raises(TypeError, match="Argument 'schema' has incorrect type"):
+        pq.SortingColumn.from_ordering(None, ())
+
+    with pytest.raises(TypeError, match="Argument 'schema' has incorrect type"):
+        pq.SortingColumn.to_ordering(None, ())
+
     with pytest.raises(ValueError, match="inconsistent null placement"):
         sorting_cols = (
             pq.SortingColumn(1, nulls_first=True),
diff --git a/python/pyarrow/tests/test_array.py b/python/pyarrow/tests/test_array.py
index eb81a4409e8d..4033fd722bab 100644
--- a/python/pyarrow/tests/test_array.py
+++ b/python/pyarrow/tests/test_array.py
@@ -985,6 +985,10 @@ def test_dictionary_from_buffers(offset):
                                         offset=offset)
     assert a[offset:] == b
 
+    with pytest.raises(TypeError, match="Argument 'type' has incorrect type"):
+        pa.DictionaryArray.from_buffers(
+            None, len(a), a.indices.buffers(), a.dictionary)
+
 
 @pytest.mark.numpy
 def test_dictionary_from_numpy():
diff --git a/python/pyarrow/tests/test_dataset.py b/python/pyarrow/tests/test_dataset.py
index 0a94c0bd9875..49d6513b80fe 100644
--- a/python/pyarrow/tests/test_dataset.py
+++ b/python/pyarrow/tests/test_dataset.py
@@ -396,6 +396,12 @@ def test_filesystem_dataset(mockfs):
     # validation of required arguments
     with pytest.raises(TypeError, match="incorrect type"):
         ds.FileSystemDataset(fragments, file_format, schema)
+    with pytest.raises(TypeError, match="Fragment must not be None"):
+        ds.FileSystemDataset([None], schema=schema, format=file_format)
+    with pytest.raises(TypeError, match="Argument 'schema' has incorrect type"):
+        ds.FileSystemDataset(fragments, schema=None, format=file_format)
+    with pytest.raises(TypeError, match="Argument 'format' has incorrect type"):
+        ds.FileSystemDataset(fragments, schema=schema, format=None)
     # validation of root_partition
     with pytest.raises(TypeError, match="incorrect type"):
         ds.FileSystemDataset(fragments, schema=schema,

From f03b3c8435e067f644ebe1c8679c7a4596d3e6a5 Mon Sep 17 00:00:00 2001
From: 1fanwang <1fannnw@gmail.com>
Date: Wed, 23 Sep 2026 23:39:22 -0700
Subject: [PATCH 2/4] GH-51043: Reject null dictionary arrays

Signed-off-by: 1fanwang <1fannnw@gmail.com>
---
 python/pyarrow/array.pxi           | 2 +-
 python/pyarrow/tests/test_array.py | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/python/pyarrow/array.pxi b/python/pyarrow/array.pxi
index 9de37b807909..580f59a33204 100644
--- a/python/pyarrow/array.pxi
+++ b/python/pyarrow/array.pxi
@@ -4352,7 +4352,7 @@ cdef class DictionaryArray(Array):
 
     @staticmethod
     def from_buffers(DataType type not None, int64_t length, buffers,
-                     Array dictionary, int64_t null_count=-1,
+                     Array dictionary not None, int64_t null_count=-1,
                      int64_t offset=0):
         """
         Construct a DictionaryArray from buffers.
diff --git a/python/pyarrow/tests/test_array.py b/python/pyarrow/tests/test_array.py
index 4033fd722bab..dcd7e03a2ad0 100644
--- a/python/pyarrow/tests/test_array.py
+++ b/python/pyarrow/tests/test_array.py
@@ -988,6 +988,9 @@ def test_dictionary_from_buffers(offset):
     with pytest.raises(TypeError, match="Argument 'type' has incorrect type"):
         pa.DictionaryArray.from_buffers(
             None, len(a), a.indices.buffers(), a.dictionary)
+    with pytest.raises(TypeError, match="Argument 'dictionary' has incorrect type"):
+        pa.DictionaryArray.from_buffers(
+            a.type, len(a), a.indices.buffers(), None)
 
 
 @pytest.mark.numpy

From 82ce629325bfa1c270ef93b19db06879ceea673d Mon Sep 17 00:00:00 2001
From: 1fanwang <1fannnw@gmail.com>
Date: Wed, 23 Sep 2026 23:39:22 -0700
Subject: [PATCH 3/4] GH-51043: [Python] Validate required array buffer
 arguments

Signed-off-by: 1fanwang <1fannnw@gmail.com>
---
 python/pyarrow/array.pxi           | 10 ++++++----
 python/pyarrow/tests/test_array.py | 24 ++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/python/pyarrow/array.pxi b/python/pyarrow/array.pxi
index 580f59a33204..66793c79b9b3 100644
--- a/python/pyarrow/array.pxi
+++ b/python/pyarrow/array.pxi
@@ -1334,8 +1334,8 @@ cdef class Array(_PandasConvertible):
             (_reduce_array_data(self.sp_array.get().data().get()),)
 
     @staticmethod
-    def from_buffers(DataType type, length, buffers, null_count=-1, offset=0,
-                     children=None):
+    def from_buffers(DataType type not None, length, buffers, null_count=-1,
+                     offset=0, children=None):
         """
         Construct an Array from a sequence of buffers.
 
@@ -1391,6 +1391,8 @@ cdef class Array(_PandasConvertible):
             c_buffers.push_back(pyarrow_unwrap_buffer(buf))
 
         for child in children:
+            if child is None:
+                raise TypeError("Array child must not be None")
             c_child_data.push_back(child.ap.data())
 
         array_data = CArrayData.MakeWithChildren(type.sp_type, length,
@@ -4769,8 +4771,8 @@ cdef class RunEndEncodedArray(Array):
                                                run_ends, values, 0)
 
     @staticmethod
-    def from_buffers(DataType type, length, buffers, null_count=-1, offset=0,
-                     children=None):
+    def from_buffers(DataType type not None, length, buffers, null_count=-1,
+                     offset=0, children=None):
         """
         Construct a RunEndEncodedArray from all the parameters that make up an
         Array.
diff --git a/python/pyarrow/tests/test_array.py b/python/pyarrow/tests/test_array.py
index dcd7e03a2ad0..a0a7a41a7a6d 100644
--- a/python/pyarrow/tests/test_array.py
+++ b/python/pyarrow/tests/test_array.py
@@ -782,6 +782,9 @@ def test_array_from_buffers():
     with pytest.raises(TypeError):
         pa.Array.from_buffers(pa.int16(), 3, ['', ''], offset=1)
 
+    with pytest.raises(TypeError, match="Argument 'type' has incorrect type"):
+        pa.Array.from_buffers(type=None, length=0, buffers=[])
+
 
 def test_string_binary_from_buffers():
     array = pa.array(["a", None, "b", "c"])
@@ -818,6 +821,20 @@ def test_string_binary_from_buffers():
     assert copied.null_count == 0
 
 
+@pytest.mark.parametrize("array_type", [pa.StringArray, pa.LargeStringArray])
+def test_string_from_buffers_null_buffers(array_type):
+    empty = array_type.from_buffers(
+        length=0, value_offsets=None, data=pa.py_buffer(b""))
+    assert empty.to_pylist() == []
+
+    with pytest.raises(pa.ArrowInvalid, match="Value data buffer is null"):
+        array_type.from_buffers(length=0, value_offsets=None, data=None)
+
+    with pytest.raises(pa.ArrowInvalid, match="Non-empty array but offsets are null"):
+        array_type.from_buffers(
+            length=1, value_offsets=None, data=pa.py_buffer(b"x"))
+
+
 def test_string_view_from_buffers():
     array = pa.array(
         [
@@ -866,6 +883,10 @@ def test_list_from_buffers(list_type_factory):
         pa.Array.from_buffers(ty, 4, buffers[:ty.num_buffers],
                               children=[child, child])
 
+    with pytest.raises(TypeError, match="Array child must not be None"):
+        pa.Array.from_buffers(
+            type=ty, length=4, buffers=buffers[:ty.num_buffers], children=[None])
+
 
 def test_struct_from_buffers():
     ty = pa.struct([pa.field('a', pa.int16()), pa.field('b', pa.utf8())])
@@ -4203,6 +4224,9 @@ def test_run_end_encoded_from_buffers():
         pa.RunEndEncodedArray.from_buffers(ree_type, length, buffers,
                                            1, offset, children)
 
+    with pytest.raises(TypeError, match="Argument 'type' has incorrect type"):
+        pa.RunEndEncodedArray.from_buffers(type=None, length=0, buffers=[])
+
 
 @pytest.mark.numpy
 def test_run_end_encoded_from_array_with_type():

From cafded2f07526c210dd3dda9b51de8218e186736 Mon Sep 17 00:00:00 2001
From: 1fanwang <1fannnw@gmail.com>
Date: Wed, 23 Sep 2026 23:39:22 -0700
Subject: [PATCH 4/4] GH-51043: [Python] Reject None in more required object
 constructors

Raise TypeError instead of aborting the interpreter when ScanNodeOptions,
ProjectNodeOptions, ParquetSchema, ColumnSchema, or SubTreeFileSystem
receive None for a required argument.

Signed-off-by: 1fanwang <1fannnw@gmail.com>
---
 python/pyarrow/_acero.pyx         |  2 ++
 python/pyarrow/_dataset.pyx       |  2 +-
 python/pyarrow/_fs.pyx            |  2 +-
 python/pyarrow/_parquet.pyx       |  4 ++--
 python/pyarrow/tests/test_misc.py | 29 +++++++++++++++++++++++++++++
 5 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/python/pyarrow/_acero.pyx b/python/pyarrow/_acero.pyx
index e27509469ef5..0a5285056931 100644
--- a/python/pyarrow/_acero.pyx
+++ b/python/pyarrow/_acero.pyx
@@ -141,6 +141,8 @@ cdef class _ProjectNodeOptions(ExecNodeOptions):
             vector[c_string] c_names
 
         for expr in expressions:
+            if expr is None:
+                raise TypeError("Expression must not be None")
             c_expressions.push_back(expr.unwrap())
 
         if names is not None:
diff --git a/python/pyarrow/_dataset.pyx b/python/pyarrow/_dataset.pyx
index e06fc6caf6c9..f2f8788afd7b 100644
--- a/python/pyarrow/_dataset.pyx
+++ b/python/pyarrow/_dataset.pyx
@@ -4239,5 +4239,5 @@ class ScanNodeOptions(_ScanNodeOptions):
         Preserve implicit ordering of data.
     """
 
-    def __init__(self, Dataset dataset, **kwargs):
+    def __init__(self, Dataset dataset not None, **kwargs):
         self._set_options(dataset, kwargs)
diff --git a/python/pyarrow/_fs.pyx b/python/pyarrow/_fs.pyx
index 0739b6acba32..10b6ac52dd55 100644
--- a/python/pyarrow/_fs.pyx
+++ b/python/pyarrow/_fs.pyx
@@ -1205,7 +1205,7 @@ cdef class SubTreeFileSystem(FileSystem):
     For usage of the methods see examples for :func:`~pyarrow.fs.LocalFileSystem`.
     """
 
-    def __init__(self, base_path, FileSystem base_fs):
+    def __init__(self, base_path, FileSystem base_fs not None):
         cdef:
             c_string pathstr
             shared_ptr[CSubTreeFileSystem] wrapped
diff --git a/python/pyarrow/_parquet.pyx b/python/pyarrow/_parquet.pyx
index a1e2b1ba3003..ddb266d86712 100644
--- a/python/pyarrow/_parquet.pyx
+++ b/python/pyarrow/_parquet.pyx
@@ -1248,7 +1248,7 @@ cdef class FileMetaData(_Weakrefable):
 cdef class ParquetSchema(_Weakrefable):
     """A Parquet schema."""
 
-    def __cinit__(self, FileMetaData container):
+    def __cinit__(self, FileMetaData container not None):
         self.parent = container
         self.schema = container._metadata.schema()
 
@@ -1337,7 +1337,7 @@ cdef class ColumnSchema(_Weakrefable):
         ParquetSchema parent
         const ColumnDescriptor* descr
 
-    def __cinit__(self, ParquetSchema schema, int index):
+    def __cinit__(self, ParquetSchema schema not None, int index):
         self.parent = schema
         self.index = index  # for pickling support
         self.descr = schema.schema.Column(index)
diff --git a/python/pyarrow/tests/test_misc.py b/python/pyarrow/tests/test_misc.py
index 856873f441b4..e7cc0a459e08 100644
--- a/python/pyarrow/tests/test_misc.py
+++ b/python/pyarrow/tests/test_misc.py
@@ -270,3 +270,32 @@ def test_extension_type_constructor_errors(klass):
     msg = f"Do not call {klass.__name__}'s constructor directly, use .* instead."
     with pytest.raises(TypeError, match=msg):
         klass()
+
+
+@pytest.mark.processes
+@pytest.mark.parametrize(("module", "call", "message"), [
+    pytest.param(
+        "acero", "ScanNodeOptions(None)", "Argument 'dataset'",
+        marks=[pytest.mark.acero, pytest.mark.dataset], id="scan"),
+    pytest.param(
+        "acero", "ProjectNodeOptions([None])", "Expression must not be None",
+        marks=pytest.mark.acero, id="project"),
+    pytest.param(
+        "parquet", "ParquetSchema(None)", "Argument 'container'",
+        marks=pytest.mark.parquet, id="parquet-schema"),
+    pytest.param(
+        "parquet", "ColumnSchema(None, 0)", "Argument 'schema'",
+        marks=pytest.mark.parquet, id="column-schema"),
+    pytest.param(
+        "fs", 'SubTreeFileSystem("", None)', "Argument 'base_fs'",
+        id="subtree"),
+])
+def test_required_arrow_objects_reject_none_without_crashing(
+    module: str, call: str, message: str
+) -> None:
+    result = subprocess.run(
+        args=[sys.executable, "-c", f"import pyarrow.{module} as mod; mod.{call}"],
+        capture_output=True, text=True, timeout=30,
+    )
+    assert result.returncode == 1, result.stderr
+    assert f"TypeError: {message}" in result.stderr