From: Hans de Goede hdegoede@redhat.com
[ 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@dell.com Cc: Mario Limonciello mario.limonciello@dell.com Signed-off-by: Hans de Goede hdegoede@redhat.com Link: https://lore.kernel.org/r/20210321115901.35072-2-hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/x86/dell-wmi-sysman/sysman.c | 1 + 1 file changed, 1 insertion(+)
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);