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[meta-python,scarthgap,1/4] python3-ujson: Fix CVE-2026-32875

Message ID 20260820051630.63383-1-hthakar@cisco.com
State New
Headers show
Series [meta-python,scarthgap,1/4] python3-ujson: Fix CVE-2026-32875 | expand

Commit Message

From: Hetvi Thakar <hthakar@cisco.com>

This patch applies the upstream fix referenced in [2], using the
commit shown in [1].

[1] https://github.com/ultrajson/ultrajson/commit/486bd4553dc471a1de11613bc7347a6b318e37ea
[2] https://nvd.nist.gov/vuln/detail/CVE-2026-32875

Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
---
 .../python/python3-ujson/CVE-2026-32875.patch | 199 ++++++++++++++++++
 .../python/python3-ujson_5.9.0.bb             |   1 +
 2 files changed, 200 insertions(+)
 create mode 100644 meta-python/recipes-devtools/python/python3-ujson/CVE-2026-32875.patch
diff mbox series

Patch

diff --git a/meta-python/recipes-devtools/python/python3-ujson/CVE-2026-32875.patch b/meta-python/recipes-devtools/python/python3-ujson/CVE-2026-32875.patch
new file mode 100644
index 0000000000..5727412835
--- /dev/null
+++ b/meta-python/recipes-devtools/python/python3-ujson/CVE-2026-32875.patch
@@ -0,0 +1,199 @@ 
+From efe3a00499a74ff44867711f40f9bcc279d2ea92 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Br=C3=A9nainn=20Woodsend?= <bwoodsend@gmail.com>
+Date: Wed, 4 Mar 2026 22:28:11 +0000
+Subject: [PATCH] Fix buffer overflow/infinite loop from indent handling
+
+If indent * nest depth is large enough to overflow an int, it causes the
+required output buffer size to be underestimated leading to a buffer
+overflow.
+
+The offending arithmetic is upgraded to a ptrdiff_t and indent is
+artificially capped. An overflow is still technically possible given a
+high enough recursion depth but not without first consuming petabytes of
+RAM.
+
+If indent is negative, it causes a size_t to underflow to some number a
+little bellow size_t max. If that underflow isn't accidentally rectified
+by a subsequent overflow (if -indent * (nest_depth + 1) >
+current_buffer_size) then the buffer up-sizer gets stuck in an infinite
+loop trying to find a power of two that fits in a size_t but is greater
+that size_t max / 2.
+
+It's hard to tell if `ujson.dumps(..., indent=-1)` was ever an
+intentional feature but I don't feel comfortable breaking it in a
+security fix. For now, the dubious *any negative indent -> pad colons
+but add no indentation or newlines* behaviour is preserved but
+internally the indent is clipped to -1 and all subsequent indentation
+code paths are skipped over.
+
+CVE: CVE-2026-32875
+Upstream-Status: Backport [https://github.com/ultrajson/ultrajson/commit/486bd4553dc471a1de11613bc7347a6b318e37ea]
+
+Backport Changes:
+- Adjusted source paths for ujson 5.9.0's pre-src-layout tree.
+
+(cherry picked from commit 486bd4553dc471a1de11613bc7347a6b318e37ea)
+Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
+---
+ lib/ultrajson.h     |  3 ++-
+ lib/ultrajsonenc.c  | 16 +++++++++-------
+ python/objToJSON.c  | 16 +++++++++++++++-
+ tests/test_ujson.py | 20 ++++++++++++++++++--
+ 4 files changed, 44 insertions(+), 11 deletions(-)
+
+diff --git a/lib/ultrajson.h b/lib/ultrajson.h
+index 143cd9e..4560f4d 100644
+--- a/lib/ultrajson.h
++++ b/lib/ultrajson.h
+@@ -54,6 +54,7 @@ tree doesn't have cyclic references.
+ #define __ULTRAJSON_H__
+ 
+ #include <stdio.h>
++#include <stddef.h>
+ 
+ // Max decimals to encode double floating point numbers with
+ #ifndef JSON_DOUBLE_MAX_DECIMALS
+@@ -257,7 +258,7 @@ typedef struct __JSONObjectEncoder
+ 
+   /*
+   Configuration for spaces of indent */
+-  int indent;
++  ptrdiff_t indent;
+ 
+   /*
+   If true, NaN will be encoded as a string matching the Python standard library's JSON behavior.
+diff --git a/lib/ultrajsonenc.c b/lib/ultrajsonenc.c
+index 9ec2faf..0f9fde3 100644
+--- a/lib/ultrajsonenc.c
++++ b/lib/ultrajsonenc.c
+@@ -575,7 +575,7 @@ static void Buffer_AppendIndentNewlineUnchecked(JSONObjectEncoder *enc)
+ 
+ static void Buffer_AppendIndentUnchecked(JSONObjectEncoder *enc, JSINT32 value)
+ {
+-  int i;
++  ptrdiff_t i;
+   if (enc->indent > 0)
+     while (value-- > 0)
+       for (i = 0; i < enc->indent; i++)
+@@ -741,10 +741,11 @@ static void encode(JSOBJ obj, JSONObjectEncoder *enc, const char *name, size_t c
+ 
+       Buffer_AppendCharUnchecked (enc, '[');
+ 
++      // The extra 1 byte covers the optional newline.
++      size_t per_item_reserve = (enc->indent > 0 ? enc->indent : 0) * (enc->level + 1) + enc->itemSeparatorLength + 1;
+       while (enc->iterNext(obj, &tc))
+       {
+-        // The extra 1 byte covers the optional newline.
+-        Buffer_Reserve (enc, enc->indent * (enc->level + 1) + enc->itemSeparatorLength + 1);
++        Buffer_Reserve (enc, per_item_reserve);
+ 
+         if (count > 0)
+         {
+@@ -769,7 +770,7 @@ static void encode(JSOBJ obj, JSONObjectEncoder *enc, const char *name, size_t c
+ 
+       enc->iterEnd(obj, &tc);
+ 
+-      if (count > 0) {
++      if (count > 0 && enc->indent > 0) {
+         // Reserve space for the indentation plus the newline.
+         Buffer_Reserve (enc, enc->indent * enc->level + 1);
+         Buffer_AppendIndentNewlineUnchecked (enc);
+@@ -786,10 +787,11 @@ static void encode(JSOBJ obj, JSONObjectEncoder *enc, const char *name, size_t c
+ 
+       Buffer_AppendCharUnchecked (enc, '{');
+ 
++      // The extra 1 byte covers the optional newline.
++      size_t reserve_size = (enc->indent > 0 ? enc->indent : 0) * (enc->level + 1) + enc->itemSeparatorLength + 1;
+       while ((res = enc->iterNext(obj, &tc)))
+       {
+-        // The extra 1 byte covers the optional newline.
+-        Buffer_Reserve (enc, enc->indent * (enc->level + 1) + enc->itemSeparatorLength + 1);
++        Buffer_Reserve (enc, reserve_size);
+ 
+         if(res < 0)
+         {
+@@ -823,7 +825,7 @@ static void encode(JSOBJ obj, JSONObjectEncoder *enc, const char *name, size_t c
+ 
+       enc->iterEnd(obj, &tc);
+ 
+-      if (count > 0) {
++      if (count > 0 && enc->indent > 0) {
+         Buffer_Reserve (enc, enc->indent * enc->level + 1);
+         Buffer_AppendIndentNewlineUnchecked (enc);
+         Buffer_AppendIndentUnchecked (enc, enc->level);
+diff --git a/python/objToJSON.c b/python/objToJSON.c
+index b754819..9013205 100644
+--- a/python/objToJSON.c
++++ b/python/objToJSON.c
+@@ -678,6 +678,7 @@ PyObject* objToJSON(PyObject* self, PyObject *args, PyObject *kwargs)
+   PyObject *separatorsKeyBytes = NULL;
+   int allowNan = -1;
+   int orejectBytes = -1;
++  int indent = 0;
+   size_t retLen;
+ 
+   JSONObjectEncoder encoder =
+@@ -714,7 +715,7 @@ PyObject* objToJSON(PyObject* self, PyObject *args, PyObject *kwargs)
+ 
+   PRINTMARK();
+ 
+-  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|OOOOiiiOO", kwlist, &oinput, &oensureAscii, &oencodeHTMLChars, &oescapeForwardSlashes, &osortKeys, &encoder.indent, &allowNan, &orejectBytes, &odefaultFn, &oseparators))
++  if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|OOOOiiiOO", kwlist, &oinput, &oensureAscii, &oencodeHTMLChars, &oescapeForwardSlashes, &osortKeys, &indent, &allowNan, &orejectBytes, &odefaultFn, &oseparators))
+   {
+     return NULL;
+   }
+@@ -761,6 +762,19 @@ PyObject* objToJSON(PyObject* self, PyObject *args, PyObject *kwargs)
+     encoder.rejectBytes = orejectBytes;
+   }
+ 
++  if (indent < -1)
++  {
++    encoder.indent = -1;
++  }
++  else if (indent > 1000)
++  {
++    PyErr_SetString(PyExc_ValueError, "Maximum allowed indentation is 1000");
++    return NULL;
++  }
++  else {
++    encoder.indent = indent;
++  }
++
+   if (oseparators != NULL && oseparators != Py_None)
+   {
+     if (!PyTuple_Check(oseparators))
+diff --git a/tests/test_ujson.py b/tests/test_ujson.py
+index 506666d..d24edb0 100644
+--- a/tests/test_ujson.py
++++ b/tests/test_ujson.py
+@@ -1050,9 +1050,25 @@ def test_default_function():
+         ujson.dumps(unjsonable_obj, default=default)
+ 
+ 
+-@pytest.mark.parametrize("indent", list(range(65537, 65542)))
++@pytest.mark.parametrize("indent", [999, 1000, 1001, 1 << 30, 1 << 63, 1 << 128])
+ def test_dump_huge_indent(indent):
+-    ujson.encode({"a": True}, indent=indent)
++    obj = {"list": [1, [2, 3], 4], "nested": {"key": "value", "a": True}}
++    if indent <= 1000:
++        assert ujson.loads(ujson.encode(obj, indent=indent)) == obj
++    else:
++        with pytest.raises((ValueError, OverflowError)):
++            ujson.encode(obj, indent=indent)
++
++
++def test_negative_indent():
++    obj = {"a": [1, 2], "b": "c"}
++    assert ujson.dumps(obj) == '{"a":[1,2],"b":"c"}'
++    assert ujson.dumps(obj, 0) == '{"a":[1,2],"b":"c"}'
++    assert ujson.dumps(obj, indent=-1) == '{"a": [1,2],"b": "c"}'
++    assert ujson.dumps(obj, indent=-1000000) == '{"a": [1,2],"b": "c"}'
++    assert (
++        ujson.dumps(obj, indent=2) == '{\n  "a": [\n    1,\n    2\n  ],\n  "b": "c"\n}'
++    )
+ 
+ 
+ @pytest.mark.parametrize("first_length", list(range(2, 7)))
+-- 
+2.35.6
+
diff --git a/meta-python/recipes-devtools/python/python3-ujson_5.9.0.bb b/meta-python/recipes-devtools/python/python3-ujson_5.9.0.bb
index b5f6be9f27..c6b69790e8 100644
--- a/meta-python/recipes-devtools/python/python3-ujson_5.9.0.bb
+++ b/meta-python/recipes-devtools/python/python3-ujson_5.9.0.bb
@@ -11,6 +11,7 @@  inherit pypi ptest setuptools3
 SRC_URI += " \
     file://run-ptest \
     file://0001-setup.py-Do-not-strip-debugging-symbols.patch \
+    file://CVE-2026-32875.patch \
 "
 
 DEPENDS += "python3-setuptools-scm-native"