diff --git a/src/libsystemd/sd-device/sd-device.c b/src/libsystemd/sd-device/sd-device.c
index e6b05b636a..ef67c649d1 100644
--- a/src/libsystemd/sd-device/sd-device.c
+++ b/src/libsystemd/sd-device/sd-device.c
@@ -30,6 +30,7 @@
 #include "string-util.h"
 #include "strv.h"
 #include "time-util.h"
+#include "utf8.h"
 
 int device_new_aux(sd_device **ret) {
         sd_device *device;
@@ -81,12 +82,34 @@ static sd_device* device_free(sd_device *device) {
 
 DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_device, sd_device, device_free);
 
+static bool property_is_valid(const char *key, const char *value) {
+        /* Device properties may be saved to database file, then may be parsed from the file. When if a
+         * property contains spurious characters, then the parser may be confused. Let's refuse spurious
+         * properties, even if it is internal, which will not be saved to database file, for consistency. */
+
+        if (isempty(key) || !in_charset(key, ALPHANUMERICAL "_."))
+                return false;
+
+        /* an empty value means unset the property, hence that's fine. */
+        if (isempty(value))
+                return true;
+
+        /* refuse invalid UTF8 and control characters */
+        if (!utf8_is_valid(value) || string_has_cc(value, /* ok= */ NULL))
+                return false;
+
+        return true;
+}
+
 int device_add_property_aux(sd_device *device, const char *key, const char *value, bool db) {
         OrderedHashmap **properties;
 
         assert(device);
         assert(key);
 
+        if (!property_is_valid(key, value))
+                return -EINVAL;
+
         if (db)
                 properties = &device->properties_db;
         else
diff --git a/src/libsystemd/sd-device/test-sd-device.c b/src/libsystemd/sd-device/test-sd-device.c
index db7c9420cc..43b76f46e9 100644
--- a/src/libsystemd/sd-device/test-sd-device.c
+++ b/src/libsystemd/sd-device/test-sd-device.c
@@ -841,6 +841,54 @@ TEST(devname_from_devnum) {
         }
 }
 
+TEST(device_add_property) {
+        _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
+        const char *val;
+
+        ASSERT_OK(sd_device_new_from_syspath(&dev, "/sys/class/net/lo"));
+
+        /* add a property */
+        ASSERT_OK(device_add_property(dev, "hoge", "foo"));
+        ASSERT_OK(sd_device_get_property_value(dev, "hoge", &val));
+        ASSERT_STREQ(val, "foo");
+
+        /* update an existing property */
+        ASSERT_OK(device_add_property(dev, "hoge", "bar"));
+        ASSERT_OK(sd_device_get_property_value(dev, "hoge", &val));
+        ASSERT_STREQ(val, "bar");
+
+        /* remove an existing property */
+        ASSERT_OK(device_add_property(dev, "hoge", NULL));
+        ASSERT_ERROR(sd_device_get_property_value(dev, "hoge", &val), ENOENT);
+
+        /* add a property again */
+        ASSERT_OK(device_add_property(dev, "hoge", "foo"));
+        ASSERT_OK(sd_device_get_property_value(dev, "hoge", &val));
+        ASSERT_STREQ(val, "foo");
+
+        /* remove it with an empty string */
+        ASSERT_OK(device_add_property(dev, "hoge", ""));
+        ASSERT_ERROR(sd_device_get_property_value(dev, "hoge", &val), ENOENT);
+
+        /* check internal property (starting with dot) */
+        ASSERT_OK(device_add_property(dev, ".hoge", "baz"));
+        ASSERT_OK(sd_device_get_property_value(dev, ".hoge", &val));
+        ASSERT_STREQ(val, "baz");
+
+        /* refuse invalid property names */
+        ASSERT_ERROR(device_add_property(dev, "hoge-hoge", "aaa"), EINVAL);
+        ASSERT_ERROR(device_add_property(dev, "hoge=hoge", "aaa"), EINVAL);
+        ASSERT_ERROR(device_add_property(dev, "hoge hoge", "aaa"), EINVAL);
+        ASSERT_ERROR(device_add_property(dev, "hoge\nhoge", "aaa"), EINVAL);
+        ASSERT_ERROR(device_add_property(dev, "hoge\rhoge", "aaa"), EINVAL);
+        ASSERT_ERROR(device_add_property(dev, "hoge\thoge", "aaa"), EINVAL);
+
+        /* refuse invalid property values */
+        ASSERT_ERROR(device_add_property(dev, "hoge", "aaa\naaa"), EINVAL);
+        ASSERT_ERROR(device_add_property(dev, "hoge", "aaa\raaa"), EINVAL);
+        ASSERT_ERROR(device_add_property(dev, "hoge", "aaa\taaa"), EINVAL);
+}
+
 static int intro(void) {
         int r;