python3-cbor2: Fix CVE-2025-64076

Upstream-Status: Backport from 2349197bea

Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
Signed-off-by: Anuj Mittal <anuj.mittal@oss.qualcomm.com>

meta-python/recipes-devtools/python/python3-cbor2/CVE-2025-64076.patch

@@ -0,0 +1,91 @@
+From 2349197bea8ebd1bf57a68f4a6549d8fd7585e66 Mon Sep 17 00:00:00 2001
+From: Chenhao <24435007+tylzh97@users.noreply.github.com>
+Date: Wed, 22 Oct 2025 20:39:31 +0800
+Subject: [PATCH] Fix: bug in `decode_definite_long_string()` that causes
+ incorrect chunk length calculation (#265)
+
+Upstream-Status: Backport [https://github.com/agronholm/cbor2/commit/2349197bea8ebd1bf57a68f4a6549d8fd7585e66]
+CVE: CVE-2025-64076
+Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
+---
+ docs/versionhistory.rst |  2 ++
+ source/decoder.c        |  8 +++++++-
+ tests/test_decoder.py   | 22 ++++++++++++++++++++++
+ 3 files changed, 31 insertions(+), 1 deletion(-)
+
+diff --git a/docs/versionhistory.rst b/docs/versionhistory.rst
+index c8566ca..21960ff 100644
+--- a/docs/versionhistory.rst
++++ b/docs/versionhistory.rst
+@@ -8,6 +8,8 @@ This library adheres to `Semantic Versioning <http://semver.org/>`_.
+ **5.6.3** (2024-04-11)
+ 
+ - Fixed decoding of epoch-based dates being affected by the local time zone in the C extension
++- Fixed a read(-1) vulnerability caused by boundary handling error
++  (#264 <https://github.com/agronholm/cbor2/issues/264>_; PR by @tylzh97)
+ 
+ **5.6.2** (2024-02-19)
+ 
+diff --git a/source/decoder.c b/source/decoder.c
+index 6fd74ce..bea7736 100644
+--- a/source/decoder.c
++++ b/source/decoder.c
+@@ -757,7 +757,7 @@ decode_definite_long_string(CBORDecoderObject *self, Py_ssize_t length)
+     char *buffer = NULL;
+     while (left) {
+         // Read up to 65536 bytes of data from the stream
+-        Py_ssize_t chunk_length = 65536 - buffer_size;
++        Py_ssize_t chunk_length = 65536 - buffer_length;
+         if (left < chunk_length)
+             chunk_length = left;
+ 
+@@ -827,7 +827,13 @@ decode_definite_long_string(CBORDecoderObject *self, Py_ssize_t length)
+                 memcpy(buffer, bytes_buffer + consumed, unconsumed);
+             }
+             buffer_length = unconsumed;
++        } else {
++            // All bytes consumed, reset buffer_length
++            buffer_length = 0;
+         }
++
++        Py_DECREF(chunk);
++        chunk = NULL;
+     }
+ 
+     if (ret && string_namespace_add(self, ret, length) == -1)
+diff --git a/tests/test_decoder.py b/tests/test_decoder.py
+index 485c604..47e6ac9 100644
+--- a/tests/test_decoder.py
++++ b/tests/test_decoder.py
+@@ -260,6 +260,28 @@ def test_string_oversized(impl) -> None:
+         (impl.loads(unhexlify("aeaeaeaeaeaeaeaeae0108c29843d90100d8249f0000aeaeffc26ca799")),)
+ 
+ 
++def test_string_issue_264_multiple_chunks_utf8_boundary(impl) -> None:
++    """Test for Issue #264: UTF-8 characters split across multiple 65536-byte chunk boundaries."""
++    import struct
++
++    # Construct: 65535 'a' + '€' (3 bytes) + 65533 'b' + '€' (3 bytes) + 100 'd'
++    # Total: 131174 bytes, which spans 3 chunks (65536 + 65536 + 102)
++    total_bytes = 65535 + 3 + 65533 + 3 + 100
++
++    payload = b"\x7a" + struct.pack(">I", total_bytes)  # major type 3, 4-byte length
++    payload += b"a" * 65535
++    payload += "€".encode()  # U+20AC: E2 82 AC
++    payload += b"b" * 65533
++    payload += "€".encode()
++    payload += b"d" * 100
++
++    expected = "a" * 65535 + "€" + "b" * 65533 + "€" + "d" * 100
++
++    result = impl.loads(payload)
++    assert result == expected
++    assert len(result) == 131170  # 65535 + 1 + 65533 + 1 + 100 characters
++
++
+ @pytest.mark.parametrize(
+     "payload, expected",
+     [
+-- 
+2.43.0
+

meta-python/recipes-devtools/python/python3-cbor2_5.6.3.bb

@@ -12,6 +12,7 @@ DEPENDS += "python3-setuptools-scm-native"
 
 SRC_URI += " \
         file://run-ptest \
+        file://CVE-2025-64076.patch \
 "
 
 RDEPENDS:${PN}-ptest += " \