platform/x86: think-lmi: Abort probe on analyze failure

A Lenovo ThinkStation S20 (4157CTO BIOS 60KT41AUS) fails to boot on
recent kernels including the think-lmi driver, due to the fact that
errors returned by the tlmi_analyze() function are ignored by
tlmi_probe(), where  tlmi_sysfs_init() is called unconditionally.
This results in making use of an array of already freed, non-null
pointers and other uninitialized globals, causing all sorts of nasty
kobject and memory faults.

Make use of the analyze function return value, free a couple leaked
allocations, and remove the settings_count field, which is incremented
but never consumed.

Fixes: a40cd7ef22fb ("platform/x86: think-lmi: Add WMI interface support on Lenovo platforms")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Mark Gross <markgross@kernel.org>
Reviewed-by: Mark Pearson <markpearson@lenovo.com>
Link: https://lore.kernel.org/r/163639463588.1330483.15850167112490200219.stgit@omen
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c
index 9472aae..c4d9c45 100644 (file)
--- a/drivers/platform/x86/think-lmi.c
+++ b/drivers/platform/x86/think-lmi.c
@@ -888,8 +888,10 @@ static int tlmi_analyze(void)
                        break;
                if (!item)
                        break;
-               if (!*item)
+               if (!*item) {
+                       kfree(item);
                        continue;
+               }
 
                /* It is not allowed to have '/' for file name. Convert it into '\'. */
                strreplace(item, '/', '\\');
@@ -902,6 +904,7 @@ static int tlmi_analyze(void)
                setting = kzalloc(sizeof(*setting), GFP_KERNEL);
                if (!setting) {
                        ret = -ENOMEM;
+                       kfree(item);
                        goto fail_clear_attr;
                }
                setting->index = i;
@@ -916,7 +919,6 @@ static int tlmi_analyze(void)
                }
                kobject_init(&setting->kobj, &tlmi_attr_setting_ktype);
                tlmi_priv.setting[i] = setting;
-               tlmi_priv.settings_count++;
                kfree(item);
        }
 
@@ -983,7 +985,12 @@ static void tlmi_remove(struct wmi_device *wdev)
 
 static int tlmi_probe(struct wmi_device *wdev, const void *context)
 {
-       tlmi_analyze();
+       int ret;
+
+       ret = tlmi_analyze();
+       if (ret)
+               return ret;
+
        return tlmi_sysfs_init();
 }
 

diff --git a/drivers/platform/x86/think-lmi.h b/drivers/platform/x86/think-lmi.h
index f8e2682..2ce5086 100644 (file)
--- a/drivers/platform/x86/think-lmi.h
+++ b/drivers/platform/x86/think-lmi.h
@@ -55,7 +55,6 @@ struct tlmi_attr_setting {
 struct think_lmi {
        struct wmi_device *wmi_device;
 
-       int settings_count;
        bool can_set_bios_settings;
        bool can_get_bios_selections;
        bool can_set_bios_password;