python3: Backport patch to fix an issue in subinterpreters

This adds a backport patch that fixes a problem in subinterpreters related
to the garbagecollector. Without the patch, there are random segfaults in
several Kodi addons that use python3-sqlite3. Presumably there are real world
issues in other programs as well.

(From OE-Core rev: 39d57ef7e341a048b94bc5dd9c29d58f57e06f19)

Signed-off-by: Markus Volk <f_l_k@t-online.de>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Markus Volk
2022-07-04 15:21:41 +02:00
committed by Richard Purdie
parent 66f67f397e
commit 8fa95bb599
2 changed files with 55 additions and 0 deletions

View File

@@ -0,0 +1,54 @@
From 178a238f25ab8aff7689d7a09d66dc1583ecd6cb Mon Sep 17 00:00:00 2001
From: "Miss Islington (bot)"
<31488909+miss-islington@users.noreply.github.com>
Date: Wed, 4 May 2022 03:23:29 -0700
Subject: [PATCH 01/40] gh-92036: Fix gc_fini_untrack() (GH-92037)
Fix a crash in subinterpreters related to the garbage collector. When
a subinterpreter is deleted, untrack all objects tracked by its GC.
To prevent a crash in deallocator functions expecting objects to be
tracked by the GC, leak a strong reference to these objects on
purpose, so they are never deleted and their deallocator functions
are not called.
(cherry picked from commit 14243369b5f80613628a565c224bba7fb3fcacd8)
Co-authored-by: Victor Stinner <vstinner@python.org>
Upstream-Status: Backport
---
.../2022-04-28-23-37-30.gh-issue-92036.GZJAC9.rst | 5 +++++
Modules/gcmodule.c | 6 ++++++
2 files changed, 11 insertions(+)
create mode 100644 Misc/NEWS.d/next/Core and Builtins/2022-04-28-23-37-30.gh-issue-92036.GZJAC9.rst
diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-04-28-23-37-30.gh-issue-92036.GZJAC9.rst b/Misc/NEWS.d/next/Core and Builtins/2022-04-28-23-37-30.gh-issue-92036.GZJAC9.rst
new file mode 100644
index 0000000000..78094c5e4f
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2022-04-28-23-37-30.gh-issue-92036.GZJAC9.rst
@@ -0,0 +1,5 @@
+Fix a crash in subinterpreters related to the garbage collector. When a
+subinterpreter is deleted, untrack all objects tracked by its GC. To prevent a
+crash in deallocator functions expecting objects to be tracked by the GC, leak
+a strong reference to these objects on purpose, so they are never deleted and
+their deallocator functions are not called. Patch by Victor Stinner.
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index 805a159d53..43ae6fa98b 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -2170,6 +2170,12 @@ gc_fini_untrack(PyGC_Head *list)
for (gc = GC_NEXT(list); gc != list; gc = GC_NEXT(list)) {
PyObject *op = FROM_GC(gc);
_PyObject_GC_UNTRACK(op);
+ // gh-92036: If a deallocator function expect the object to be tracked
+ // by the GC (ex: func_dealloc()), it can crash if called on an object
+ // which is no longer tracked by the GC. Leak one strong reference on
+ // purpose so the object is never deleted and its deallocator is not
+ // called.
+ Py_INCREF(op);
}
}
--
2.25.1