This is a note to let you know that I've just added the patch titled
platform/x86: dell-wmi-sysman: Fix crash caused by calling kset_unregister twice
to the 5.11-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
platform-x86-dell-wmi-sysman-fix-crash-caused-by-cal.patch
and it can be found in the queue-5.11 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3ebf30cff473c347db169374502cb6938f3b22c7
Author: Hans de Goede <hdegoede@xxxxxxxxxx>
Date: Sun Mar 21 12:58:55 2021 +0100
platform/x86: dell-wmi-sysman: Fix crash caused by calling kset_unregister twice
[ Upstream commit d939cd96b9df6dcde1605fab23bbd6307e11f930 ]
On some system the WMI GUIDs used by dell-wmi-sysman are present but there
are no enum type attributes, this causes init_bios_attributes() to return
-ENODEV, after which sysman_init() does a "goto fail_create_group" and then
calls release_attributes_data().
release_attributes_data() calls kset_unregister(wmi_priv.main_dir_kset);
but before this commit it was missing a "wmi_priv.main_dir_kset = NULL;"
statement; and after calling release_attributes_data() the sysman_init()
error handling does this:
if (wmi_priv.main_dir_kset) {
kset_unregister(wmi_priv.main_dir_kset);
wmi_priv.main_dir_kset = NULL;
}
Which causes a second kset_unregister(wmi_priv.main_dir_kset), leading to
a double-free, which causes a crash.
Add the missing "wmi_priv.main_dir_kset = NULL;" statement to
release_attributes_data() to fix this double-free crash.
Fixes: e8a60aa7404b ("platform/x86: Introduce support for Systems Management Driver over WMI for Dell Systems")
Cc: Divya Bharathi <Divya_Bharathi@xxxxxxxx>
Cc: Mario Limonciello <mario.limonciello@xxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210321115901.35072-2-hdegoede@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/platform/x86/dell-wmi-sysman/sysman.c b/drivers/platform/x86/dell-wmi-sysman/sysman.c
index cb81010ba1a2..c1997db74cca 100644
--- a/drivers/platform/x86/dell-wmi-sysman/sysman.c
+++ b/drivers/platform/x86/dell-wmi-sysman/sysman.c
@@ -388,6 +388,7 @@ static void release_attributes_data(void)
if (wmi_priv.main_dir_kset) {
destroy_attribute_objs(wmi_priv.main_dir_kset);
kset_unregister(wmi_priv.main_dir_kset);
+ wmi_priv.main_dir_kset = NULL;
}
mutex_unlock(&wmi_priv.mutex);
