systemd/0315-sd-event-add-sd_event_source_disable_unref-helper.patch

131 lines
5.5 KiB
Diff

From 73b87f8c73af714a32e7b56b217cd4e4f46a5ea7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Wed, 8 May 2019 14:39:57 +0200
Subject: [PATCH] sd-event: add sd_event_source_disable_unref() helper
(cherry picked from commit afd15bbb4b6414b9356799c63029e36642dae8e4)
Related: CVE-2020-1712
---
man/rules/meson.build | 4 +++-
man/sd_event_source_unref.xml | 30 +++++++++++++++++++-----------
src/libsystemd/libsystemd.sym | 1 +
src/libsystemd/sd-event/sd-event.c | 6 ++++++
src/systemd/sd-event.h | 1 +
5 files changed, 30 insertions(+), 12 deletions(-)
diff --git a/man/rules/meson.build b/man/rules/meson.build
index 989d11c9b9..7ae94ea265 100644
--- a/man/rules/meson.build
+++ b/man/rules/meson.build
@@ -340,7 +340,9 @@ manpages = [
['sd_event_source_set_userdata', '3', ['sd_event_source_get_userdata'], ''],
['sd_event_source_unref',
'3',
- ['sd_event_source_ref', 'sd_event_source_unrefp'],
+ ['sd_event_source_disable_unref',
+ 'sd_event_source_ref',
+ 'sd_event_source_unrefp'],
''],
['sd_event_wait',
'3',
diff --git a/man/sd_event_source_unref.xml b/man/sd_event_source_unref.xml
index d1b83c57aa..af8fed33f2 100644
--- a/man/sd_event_source_unref.xml
+++ b/man/sd_event_source_unref.xml
@@ -22,6 +22,7 @@
<refname>sd_event_source_unref</refname>
<refname>sd_event_source_unrefp</refname>
<refname>sd_event_source_ref</refname>
+ <refname>sd_event_source_disable_unref</refname>
<refpurpose>Increase or decrease event source reference counters</refpurpose>
</refnamediv>
@@ -45,6 +46,10 @@
<paramdef>sd_event_source *<parameter>source</parameter></paramdef>
</funcprototype>
+ <funcprototype>
+ <funcdef>sd_event_source* <function>sd_event_source_disable_unref</function></funcdef>
+ <paramdef>sd_event_source *<parameter>source</parameter></paramdef>
+ </funcprototype>
</funcsynopsis>
</refsynopsisdiv>
@@ -80,23 +85,26 @@
the passed event source object is
<constant>NULL</constant>.</para>
- <para>Note that event source objects stay alive and may be
- dispatched as long as they have a reference counter greater than
- zero. In order to drop a reference of an event source and make
- sure the associated event source handler function is not called
- anymore it is recommended to combine a call of
+ <para>Note that event source objects stay alive and may be dispatched as long as they have a reference
+ counter greater than zero. In order to drop a reference of an event source and make sure the associated
+ event source handler function is not called anymore it is recommended to combine a call of
<function>sd_event_source_unref()</function> with a prior call to
- <function>sd_event_source_set_enabled()</function> with
- <constant>SD_EVENT_OFF</constant>.</para>
+ <function>sd_event_source_set_enabled()</function> with <constant>SD_EVENT_OFF</constant> or call
+ <function>sd_event_source_disable_unref()</function>, see below.</para>
+
+ <para><function>sd_event_source_disable_unref()</function> combines a call to
+ <function>sd_event_source_set_enabled()</function> with <constant>SD_EVENT_OFF</constant> with
+ <function>sd_event_source_unref()</function>. This ensures that the source is disabled before the local
+ reference to it is lost. The <parameter>source</parameter> parameter is allowed to be
+ <constant>NULL</constant>.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
- <para><function>sd_event_source_unref()</function> always returns
- <constant>NULL</constant>.
- <function>sd_event_source_ref()</function> always returns the
- event source object passed in.</para>
+ <para><function>sd_event_source_unref()</function> and
+ <function>sd_event_source_disable_unref()</function> always return <constant>NULL</constant>.
+ <function>sd_event_source_ref()</function> always returns the event source object passed in.</para>
</refsect1>
<xi:include href="libsystemd-pkgconfig.xml" />
diff --git a/src/libsystemd/libsystemd.sym b/src/libsystemd/libsystemd.sym
index e9972593a6..778e88a16c 100644
--- a/src/libsystemd/libsystemd.sym
+++ b/src/libsystemd/libsystemd.sym
@@ -570,4 +570,5 @@ global:
sd_event_source_set_destroy_callback;
sd_event_source_get_destroy_callback;
sd_bus_enqueue_for_read;
+ sd_event_source_disable_unref;
} LIBSYSTEMD_238;
diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c
index d53b9a7026..0d3bf5cbb6 100644
--- a/src/libsystemd/sd-event/sd-event.c
+++ b/src/libsystemd/sd-event/sd-event.c
@@ -580,6 +580,12 @@ _public_ sd_event* sd_event_unref(sd_event *e) {
return NULL;
}
+_public_ sd_event_source* sd_event_source_disable_unref(sd_event_source *s) {
+ if (s)
+ (void) sd_event_source_set_enabled(s, SD_EVENT_OFF);
+ return sd_event_source_unref(s);
+}
+
static bool event_pid_changed(sd_event *e) {
assert(e);
diff --git a/src/systemd/sd-event.h b/src/systemd/sd-event.h
index 7fcae4ac49..9876be01c6 100644
--- a/src/systemd/sd-event.h
+++ b/src/systemd/sd-event.h
@@ -113,6 +113,7 @@ int sd_event_get_iteration(sd_event *e, uint64_t *ret);
sd_event_source* sd_event_source_ref(sd_event_source *s);
sd_event_source* sd_event_source_unref(sd_event_source *s);
+sd_event_source* sd_event_source_disable_unref(sd_event_source *s);
sd_event *sd_event_source_get_event(sd_event_source *s);
void* sd_event_source_get_userdata(sd_event_source *s);