[PATCH 1/1] kobject: Don't emit change events if not in sysfs - Abhishek Pandit-Subedi

From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	rafael.j.wysocki@intel.com, swboyd@chromium.org,
	linux-kernel@vger.kernel.org
Cc: linux-pm@vger.kernel.org,
	Abhishek Pandit-Subedi <abhishekpandit@chromium.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>
Subject: [PATCH 1/1] kobject: Don't emit change events if not in sysfs
Date: Mon, 19 Oct 2020 15:32:57 -0700	[thread overview]
Message-ID: <20201019153232.1.I797f9874972a07fc381fe586b6748ce71c7b1fda@changeid> (raw)
In-Reply-To: <20201019223257.261223-1-abhishekpandit@chromium.org>

Add a check to make sure the kobj is created and in sysfs before sending
a change event notification. Otherwise, udev rules that depend on the
change notification may find that the path that changed doesn't actually
exist.

Fixes: a45aca510b73b7 (PM: sleep: core: Emit changed uevent on wakeup_sysfs_add/remove)
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
---

 lib/kobject_uevent.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 7998affa45d49a..f08197e907d5ce 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -473,6 +473,11 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
 	if (action == KOBJ_REMOVE)
 		kobj->state_remove_uevent_sent = 1;
 
+	if (action == KOBJ_CHANGE && !kobj->state_in_sysfs) {
+		pr_debug("kobject: can't emit KOBJ_CHANGE until in sysfs\n");
+		return -EINVAL;
+	}
+
 	pr_debug("kobject: '%s' (%p): %s\n",
 		 kobject_name(kobj), kobj, __func__);
 
-- 
2.29.0.rc1.297.gfa9743e501-goog

