From 85c3b2789115a9e814326b869224ed3d16dbd170 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 1 Nov 2019 10:21:35 +0100
Subject: [PATCH 1/3] cgroup: add some basic OOM safety where it was missing

---
 src/core/cgroup.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 981aca53cd..95ebafa10d 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -360,9 +360,7 @@ static char *format_cgroup_memory_limit_comparison(char *buf, size_t l, Unit *u,
 }
 
 void cgroup_context_dump(Unit *u, FILE* f, const char *prefix) {
-        _cleanup_free_ char *disable_controllers_str = NULL;
-        _cleanup_free_ char *cpuset_cpus = NULL;
-        _cleanup_free_ char *cpuset_mems = NULL;
+        _cleanup_free_ char *disable_controllers_str = NULL, *cpuset_cpus = NULL, *cpuset_mems = NULL;
         CGroupIODeviceLimit *il;
         CGroupIODeviceWeight *iw;
         CGroupIODeviceLatency *l;
@@ -437,8 +435,8 @@ void cgroup_context_dump(Unit *u, FILE* f, const char *prefix) {
                 prefix, c->startup_cpu_shares,
                 prefix, format_timespan(q, sizeof(q), c->cpu_quota_per_sec_usec, 1),
                 prefix, format_timespan(v, sizeof(v), c->cpu_quota_period_usec, 1),
-                prefix, cpuset_cpus,
-                prefix, cpuset_mems,
+                prefix, strempty(cpuset_cpus),
+                prefix, strempty(cpuset_mems),
                 prefix, c->io_weight,
                 prefix, c->startup_io_weight,
                 prefix, c->blockio_weight,

From c259ac9aa207911bd5fd8ebf90da212e14c12d9b Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 1 Nov 2019 10:21:53 +0100
Subject: [PATCH 2/3] cpuset: fix indentation and log about OOM we otherwise
 ignore

---
 src/core/cgroup.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 95ebafa10d..ec8a262314 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -972,8 +972,10 @@ static void cgroup_apply_unified_cpuset(Unit *u, const CPUSet *cpus, const char
         _cleanup_free_ char *buf = NULL;
 
         buf = cpu_set_to_range_string(cpus);
-        if (!buf)
-            return;
+        if (!buf) {
+                log_oom();
+                return;
+        }
 
         (void) set_attribute_and_warn(u, "cpuset", name, buf);
 }

From a897a7b837b38de3bde162f4f83d9523558b3516 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 1 Nov 2019 10:22:03 +0100
Subject: [PATCH 3/3] cgroup: add missing OOM check, and shorten code a bit

cpu_set_to_range_string() can fail due to OOM. Handle that.

unit_write_settingf() exists, use it instead of formatting a string
beforehand.

cpu_set_add_all() can fail due to OOM. Let's avoid it if we don't have
to use it, just copy over the cpuset directly.
---
 src/core/dbus-cgroup.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/core/dbus-cgroup.c b/src/core/dbus-cgroup.c
index b30318b943..647c3a512c 100644
--- a/src/core/dbus-cgroup.c
+++ b/src/core/dbus-cgroup.c
@@ -926,23 +926,23 @@ int bus_cgroup_set_property(
 
                 if (!UNIT_WRITE_FLAGS_NOOP(flags)) {
                         _cleanup_free_ char *setstr = NULL;
-                        _cleanup_free_ char *data = NULL;
                         CPUSet *set;
 
                         setstr = cpu_set_to_range_string(&new_set);
+                        if (!setstr)
+                                return -ENOMEM;
 
                         if (streq(name, "AllowedCPUs"))
                                 set = &c->cpuset_cpus;
                         else
                                 set = &c->cpuset_mems;
 
-                        if (asprintf(&data, "%s=%s", name, setstr) < 0)
-                                return -ENOMEM;
-
                         cpu_set_reset(set);
-                        cpu_set_add_all(set, &new_set);
+                        *set = new_set;
+                        new_set = (CPUSet) {};
+
                         unit_invalidate_cgroup(u, CGROUP_MASK_CPUSET);
-                        unit_write_setting(u, flags, name, data);
+                        unit_write_settingf(u, flags, name, "%s=%s", name, setstr);
                 }
 
                 return 1;