From: Alexander Dahl via ptxdist <ptxdist@pengutronix.de>
To: ptxdist@pengutronix.de
Cc: Alexander Dahl <ada@thorsis.com>
Subject: [ptxdist] [PATCH] json-c: Add patches with memory fixes from upstream master
Date: Thu, 16 Jul 2026 15:27:42 +0200 [thread overview]
Message-ID: <20260716132742.3243000-1-ada@thorsis.com> (raw)
Fixing memory leak and reference counting bugs, no new release yet.
Signed-off-by: Alexander Dahl <ada@thorsis.com>
---
...e-to-clear-_user_delete-in-_json_obj.patch | 96 +++++++++
...ts-outside-assert-in-json_object_put.patch | 31 +++
...et-_userdata-NULL-in-_json_object_ma.patch | 47 +++++
...put-to-return-1-for-freed-scalars-an.patch | 195 ++++++++++++++++++
patches/json-c-0.19/series | 7 +
5 files changed, 376 insertions(+)
create mode 100644 patches/json-c-0.19/0001-Issue-934-Be-sure-to-clear-_user_delete-in-_json_obj.patch
create mode 100644 patches/json-c-0.19/0002-free-objects-outside-assert-in-json_object_put.patch
create mode 100644 patches/json-c-0.19/0003-Issue-934-Also-set-_userdata-NULL-in-_json_object_ma.patch
create mode 100644 patches/json-c-0.19/0004-fix-json_object_put-to-return-1-for-freed-scalars-an.patch
create mode 100644 patches/json-c-0.19/series
diff --git a/patches/json-c-0.19/0001-Issue-934-Be-sure-to-clear-_user_delete-in-_json_obj.patch b/patches/json-c-0.19/0001-Issue-934-Be-sure-to-clear-_user_delete-in-_json_obj.patch
new file mode 100644
index 000000000..9d30da84e
--- /dev/null
+++ b/patches/json-c-0.19/0001-Issue-934-Be-sure-to-clear-_user_delete-in-_json_obj.patch
@@ -0,0 +1,96 @@
+From: Eric Hawicz <erh+git@nimenees.com>
+Date: Sat, 4 Jul 2026 11:02:06 -0400
+Subject: [PATCH] Issue #934: Be sure to clear _user_delete in
+ _json_object_put_maybe_free() to avoid calling it twice. Add a test to check.
+
+Upstream-Status: Backport [3aa996b5b6bd96c29f2c6da98da33c3fb3d13038]
+---
+ json_object.c | 1 +
+ json_object.h | 4 ++--
+ tests/test_deep_nesting.c | 33 +++++++++++++++++++++++++++++++++
+ 3 files changed, 36 insertions(+), 2 deletions(-)
+
+diff --git a/json_object.c b/json_object.c
+index 0a619679bd7e..6cb1bdac86d5 100644
+--- a/json_object.c
++++ b/json_object.c
+@@ -303,6 +303,7 @@ static inline int _json_object_put_maybe_free(struct json_object *jso, int free_
+
+ if (jso->_user_delete)
+ jso->_user_delete(jso, jso->_userdata);
++ jso->_user_delete = NULL;
+
+ switch (jso->o_type)
+ {
+diff --git a/json_object.h b/json_object.h
+index e21138ecf1db..7edb63d4f8cb 100644
+--- a/json_object.h
++++ b/json_object.h
+@@ -259,7 +259,7 @@ JSON_EXPORT void *json_object_get_userdata(json_object *jso);
+ * The user_delete parameter is optional and may be passed as NULL, even if
+ * the userdata parameter is non-NULL. It will be called just before the
+ * json_object is deleted, after it's reference count goes to zero
+- * (see json_object_put()).
++ * (see json_object_put()) but before any child objects are freed.
+ * If this is not provided, it is up to the caller to free the userdata at
+ * an appropriate time. (i.e. after the json_object is deleted)
+ *
+@@ -293,7 +293,7 @@ JSON_EXPORT void json_object_set_userdata(json_object *jso, void *userdata,
+ * The user_delete parameter is optional and may be passed as NULL, even if
+ * the userdata parameter is non-NULL. It will be called just before the
+ * json_object is deleted, after it's reference count goes to zero
+- * (see json_object_put()).
++ * (see json_object_put()) but before any child objects are freed.
+ * If this is not provided, it is up to the caller to free the userdata at
+ * an appropriate time. (i.e. after the json_object is deleted)
+ *
+diff --git a/tests/test_deep_nesting.c b/tests/test_deep_nesting.c
+index 364c4820ea5d..9e251750c480 100644
+--- a/tests/test_deep_nesting.c
++++ b/tests/test_deep_nesting.c
+@@ -56,6 +56,37 @@ static void test_deep_nesting_tostring(const char *str)
+ json_tokener_free(tok);
+ }
+
++struct userdata_test {
++ int userdata_val;
++ char *p;
++};
++/*
++ * Check that the user_delete function is only called once, even with the
++ * newer code to avoid deeply nested calls during json_object_put().
++ */
++static void user_delete_test(struct json_object *jso, void *userdata_in)
++{
++ struct userdata_test *userdata = (struct userdata_test *)userdata_in;
++ printf("in user_delete, userdata_val=%d\n", userdata->userdata_val);
++ fflush(stdout);
++ userdata->userdata_val = 0;
++ userdata->p[0] = 'x';
++ userdata->p[8191] = 'x';
++ free(userdata->p);
++}
++static void test_nesting_with_user_delete(void)
++{
++ json_object *jso;
++ struct userdata_test userdata_val = {
++ 1, malloc(8192)
++ };
++
++ jso = json_object_new_object();
++ json_object_set_userdata(jso, &userdata_val, user_delete_test);
++ json_object_object_add(jso, "somekey", json_object_new_string("foo"));
++ json_object_put(jso);
++}
++
+ int main(int argc, char **argv)
+ {
+ char *str;
+@@ -77,5 +108,7 @@ int main(int argc, char **argv)
+
+ free(str);
+
++ test_nesting_with_user_delete();
++
+ return EXIT_SUCCESS;
+ }
diff --git a/patches/json-c-0.19/0002-free-objects-outside-assert-in-json_object_put.patch b/patches/json-c-0.19/0002-free-objects-outside-assert-in-json_object_put.patch
new file mode 100644
index 000000000..7601bc68e
--- /dev/null
+++ b/patches/json-c-0.19/0002-free-objects-outside-assert-in-json_object_put.patch
@@ -0,0 +1,31 @@
+From: Javid Khan <dxbjavid@gmail.com>
+Date: Tue, 30 Jun 2026 18:54:06 +0530
+Subject: [PATCH] free objects outside assert() in json_object_put
+
+Upstream-Status: Backport [f291fa81c6f21d925ea771a8cca597f5886309cc]
+---
+ json_object.c | 7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+diff --git a/json_object.c b/json_object.c
+index 6cb1bdac86d5..71cd25b2a6a9 100644
+--- a/json_object.c
++++ b/json_object.c
+@@ -436,11 +436,16 @@ int json_object_put(struct json_object *jso)
+ // All slots are cleared, now pop back up to the parent
+ {
+ json_object *parent = jso->_delete_parent;
++ int rc;
+ // jso is a child that's already been detached from its parent
+ // so we need to actually free it now
+ assert(jso->_ref_count == 0);
+ jso->_ref_count++; // We're the exclusive owner of jso, non-atomic add is ok.
+- assert(_json_object_put_maybe_free(jso, 1) == 0);
++ // Note: the call must not be inside assert(), or it gets
++ // compiled out when NDEBUG is defined and the memory leaks.
++ rc = _json_object_put_maybe_free(jso, 1);
++ assert(rc == 0);
++ (void)rc;
+ jso = parent;
+ // iteration will be reset at the top of the loop
+ }
diff --git a/patches/json-c-0.19/0003-Issue-934-Also-set-_userdata-NULL-in-_json_object_ma.patch b/patches/json-c-0.19/0003-Issue-934-Also-set-_userdata-NULL-in-_json_object_ma.patch
new file mode 100644
index 000000000..b235b00bd
--- /dev/null
+++ b/patches/json-c-0.19/0003-Issue-934-Also-set-_userdata-NULL-in-_json_object_ma.patch
@@ -0,0 +1,47 @@
+From: Eric Hawicz <erh+git@nimenees.com>
+Date: Sat, 4 Jul 2026 11:38:15 -0400
+Subject: [PATCH] Issue #934: Also set _userdata=NULL in
+ _json_object_maybe_free() so json_object_put doesn't try to use it as a
+ _delete_parent value. Update the test_deep_nesting test output.
+
+Upstream-Status: Backport [0c3a5a1994ed6b5957d2e878fc1298ce9aa09b3f]
+---
+ json_object.c | 7 +++++--
+ tests/test_deep_nesting.expected | 1 +
+ 2 files changed, 6 insertions(+), 2 deletions(-)
+
+diff --git a/json_object.c b/json_object.c
+index 71cd25b2a6a9..095b84e2b4ab 100644
+--- a/json_object.c
++++ b/json_object.c
+@@ -304,6 +304,8 @@ static inline int _json_object_put_maybe_free(struct json_object *jso, int free_
+ if (jso->_user_delete)
+ jso->_user_delete(jso, jso->_userdata);
+ jso->_user_delete = NULL;
++ jso->_userdata = NULL; // aka _delete_parent, but json_object_put() will
++ // have already grabbed it if it needs it.
+
+ switch (jso->o_type)
+ {
+@@ -435,10 +437,11 @@ int json_object_put(struct json_object *jso)
+
+ // All slots are cleared, now pop back up to the parent
+ {
+- json_object *parent = jso->_delete_parent;
+- int rc;
+ // jso is a child that's already been detached from its parent
+ // so we need to actually free it now
++ // Be sure to grab _delete_parent *before* freeing jso.
++ json_object *parent = jso->_delete_parent;
++ int rc;
+ assert(jso->_ref_count == 0);
+ jso->_ref_count++; // We're the exclusive owner of jso, non-atomic add is ok.
+ // Note: the call must not be inside assert(), or it gets
+diff --git a/tests/test_deep_nesting.expected b/tests/test_deep_nesting.expected
+index b869cfaabe79..b9c1ab98480f 100644
+--- a/tests/test_deep_nesting.expected
++++ b/tests/test_deep_nesting.expected
+@@ -1,2 +1,3 @@
+ Parsed depth 100000 string to json_object: yes
+ Freed json_object
++in user_delete, userdata_val=1
diff --git a/patches/json-c-0.19/0004-fix-json_object_put-to-return-1-for-freed-scalars-an.patch b/patches/json-c-0.19/0004-fix-json_object_put-to-return-1-for-freed-scalars-an.patch
new file mode 100644
index 000000000..7e57bad29
--- /dev/null
+++ b/patches/json-c-0.19/0004-fix-json_object_put-to-return-1-for-freed-scalars-an.patch
@@ -0,0 +1,195 @@
+From: Arran Cudbard-Bell <a.cudbardb@freeradius.org>
+Date: Tue, 14 Jul 2026 09:32:03 -0400
+Subject: [PATCH] fix json_object_put() to return 1 for freed scalars and empty
+ containers
+
+The iterative rewrite in 17328a67 made json_object_put() return 0 for freed scalars, strings and empty containers, contradicting the documented contract in json_object.h. Distinguish "freed" from "still referenced" in _json_object_put_maybe_free() and add regression tests.
+
+Upstream-Status: Backport [69be99ef8e99d811d7810bdf75864ae800a67e50]
+---
+ json_object.c | 49 ++++++++++++++++++++++++++++------------
+ tests/test_deep_nesting.c | 28 ++++++++++++++++++++++-
+ tests/test_deep_nesting.expected | 7 ++++++
+ 3 files changed, 69 insertions(+), 15 deletions(-)
+
+diff --git a/json_object.c b/json_object.c
+index 095b84e2b4ab..621260885620 100644
+--- a/json_object.c
++++ b/json_object.c
+@@ -273,13 +273,31 @@ struct json_object *json_object_get(struct json_object *jso)
+ }
+
+
++/**
++ * Return values for _json_object_put_maybe_free().
++ * json_object_put_still_refd and json_object_put_freed match the documented
++ * return values of json_object_put(), so they can be returned directly.
++ */
++enum json_object_put_result
++{
++ json_object_put_still_refd = 0, /* refcount decremented, object not freed */
++ json_object_put_freed = 1, /* refcount reached zero, memory released */
++ json_object_put_container = 2 /* refcount reached zero, but the object is a
++ non-empty container: the caller must free
++ the contents, then the object itself */
++};
++
+ /**
+ * Internal json_object_put function
+- * Returns 0 if we're done "freeing" the object, either because its memory
+- * was actually released, or we just needed to decrement the refcount.
+- * Returns 1 when the object is a non-empty container that still needs to be handled.
++ * Returns json_object_put_still_refd if a reference remains, and the object
++ * was not freed.
++ * Returns json_object_put_freed if the object's memory was released, either
++ * because it holds no other objects, or because free_containers was set.
++ * Returns json_object_put_container when the refcount reached zero but the
++ * object is a non-empty container; the caller must free the contents, then
++ * call this function again with free_containers set to free the object itself.
+ */
+-static inline int _json_object_put_maybe_free(struct json_object *jso, int free_containers)
++static inline enum json_object_put_result _json_object_put_maybe_free(struct json_object *jso, int free_containers)
+ {
+ /* Avoid invalid free and crash explicitly instead of (silently)
+ * segfaulting.
+@@ -298,7 +316,7 @@ static inline int _json_object_put_maybe_free(struct json_object *jso, int free_
+ if (--jso->_ref_count > 0)
+ #endif
+ {
+- return 0; // All done, caller doesn't need to do anything else
++ return json_object_put_still_refd;
+ }
+
+ if (jso->_user_delete)
+@@ -315,15 +333,15 @@ static inline int _json_object_put_maybe_free(struct json_object *jso, int free_
+ json_object_object_delete(jso);
+ break;
+ }
+- return 1;
+- case json_type_array:
++ return json_object_put_container;
++ case json_type_array:
+ // container objects are handled by the caller
+ if (free_containers || array_list_length(JC_ARRAY(jso)->c_array) == 0)
+ {
+ json_object_array_delete(jso);
+ break;
+ }
+- return 1;
++ return json_object_put_container;
+ case json_type_string:
+ json_object_string_delete(jso);
+ break;
+@@ -331,16 +349,19 @@ static inline int _json_object_put_maybe_free(struct json_object *jso, int free_
+ json_object_generic_delete(jso);
+ break;
+ }
+- return 0; // All done, caller doesn't need to do anything else
++ return json_object_put_freed;
+ }
+
+ int json_object_put(struct json_object *jso)
+ {
++ enum json_object_put_result rc;
++
+ if (!jso)
+ return 0;
+
+- if (_json_object_put_maybe_free(jso, 0) == 0)
+- return 0;
++ rc = _json_object_put_maybe_free(jso, 0);
++ if (rc != json_object_put_container)
++ return (int)rc;
+ // else, it's a non-empty container object, handle it below
+
+ // Note: jso is now a "zombie" object, _ref_count == 0 but memory not yet released
+@@ -399,7 +420,7 @@ int json_object_put(struct json_object *jso)
+ }
+
+ // Now, handle actually freeing the json_object in that slot
+- if (!child || _json_object_put_maybe_free(child, 0) == 0)
++ if (!child || _json_object_put_maybe_free(child, 0) != json_object_put_container)
+ {
+ // child is either freed, or still referenced somewhere else
+ // leave it as-is and handle the previous slot
+@@ -441,13 +462,13 @@ int json_object_put(struct json_object *jso)
+ // so we need to actually free it now
+ // Be sure to grab _delete_parent *before* freeing jso.
+ json_object *parent = jso->_delete_parent;
+- int rc;
++ enum json_object_put_result rc;
+ assert(jso->_ref_count == 0);
+ jso->_ref_count++; // We're the exclusive owner of jso, non-atomic add is ok.
+ // Note: the call must not be inside assert(), or it gets
+ // compiled out when NDEBUG is defined and the memory leaks.
+ rc = _json_object_put_maybe_free(jso, 1);
+- assert(rc == 0);
++ assert(rc == json_object_put_freed);
+ (void)rc;
+ jso = parent;
+ // iteration will be reset at the top of the loop
+diff --git a/tests/test_deep_nesting.c b/tests/test_deep_nesting.c
+index 9e251750c480..4bf24578daa1 100644
+--- a/tests/test_deep_nesting.c
++++ b/tests/test_deep_nesting.c
+@@ -81,12 +81,36 @@ static void test_nesting_with_user_delete(void)
+ 1, malloc(8192)
+ };
+
+- jso = json_object_new_object();
++ jso = json_object_new_object();
+ json_object_set_userdata(jso, &userdata_val, user_delete_test);
+ json_object_object_add(jso, "somekey", json_object_new_string("foo"));
+ json_object_put(jso);
+ }
+
++/*
++ * Check that json_object_put() returns 1 whenever the object is freed,
++ * including for scalars and empty containers, and 0 only when a
++ * reference remains.
++ */
++static void test_put_return_values(void)
++{
++ json_object *jso;
++
++ printf("put(empty object) returned %d\n", json_object_put(json_object_new_object()));
++ printf("put(empty array) returned %d\n", json_object_put(json_object_new_array()));
++ printf("put(string) returned %d\n", json_object_put(json_object_new_string("foo")));
++ printf("put(int) returned %d\n", json_object_put(json_object_new_int(42)));
++
++ jso = json_object_new_object();
++ json_object_object_add(jso, "somekey", json_object_new_string("foo"));
++ printf("put(non-empty object) returned %d\n", json_object_put(jso));
++
++ jso = json_object_new_object();
++ json_object_get(jso);
++ printf("put(still-referenced object) returned %d\n", json_object_put(jso));
++ printf("put(last reference) returned %d\n", json_object_put(jso));
++}
++
+ int main(int argc, char **argv)
+ {
+ char *str;
+@@ -110,5 +134,7 @@ int main(int argc, char **argv)
+
+ test_nesting_with_user_delete();
+
++ test_put_return_values();
++
+ return EXIT_SUCCESS;
+ }
+diff --git a/tests/test_deep_nesting.expected b/tests/test_deep_nesting.expected
+index b9c1ab98480f..2449ede3265c 100644
+--- a/tests/test_deep_nesting.expected
++++ b/tests/test_deep_nesting.expected
+@@ -1,3 +1,10 @@
+ Parsed depth 100000 string to json_object: yes
+ Freed json_object
+ in user_delete, userdata_val=1
++put(empty object) returned 1
++put(empty array) returned 1
++put(string) returned 1
++put(int) returned 1
++put(non-empty object) returned 1
++put(still-referenced object) returned 0
++put(last reference) returned 1
diff --git a/patches/json-c-0.19/series b/patches/json-c-0.19/series
new file mode 100644
index 000000000..311299a3a
--- /dev/null
+++ b/patches/json-c-0.19/series
@@ -0,0 +1,7 @@
+# generated by git-ptx-patches
+#tag:base --start-number 1
+0001-Issue-934-Be-sure-to-clear-_user_delete-in-_json_obj.patch
+0002-free-objects-outside-assert-in-json_object_put.patch
+0003-Issue-934-Also-set-_userdata-NULL-in-_json_object_ma.patch
+0004-fix-json_object_put-to-return-1-for-freed-scalars-an.patch
+# 5aff3fd086034e7fb3fdec97d3808ade - git-ptx-patches magic
base-commit: af7fe92c6398143ffbb7dfb75ae1e6de092cd15c
--
2.47.3
reply other threads:[~2026-07-16 13:27 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260716132742.3243000-1-ada@thorsis.com \
--to=ptxdist@pengutronix.de \
--cc=ada@thorsis.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox