From: Mark Pearson mpearson-lenovo@squebb.ca
[ Upstream commit c41e0121a1221894a1a9c4666156db9e1def4d6c ]
When an attribute is being changed if the Admin account is enabled, or if a password is being updated then multiple WMI calls are needed. Add mutex protection to ensure no race conditions are introduced.
Fixes: b49f72e7f96d ("platform/x86: think-lmi: Certificate authentication support") Signed-off-by: Mark Pearson mpearson-lenovo@squebb.ca Reviewed-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Reviewed-by: Hans de Goede hdegoede@redhat.com Link: https://lore.kernel.org/r/20230601200552.4396-1-mpearson-lenovo@squebb.ca Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/x86/think-lmi.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c index 78dc82bda4dde..7a145f578ef49 100644 --- a/drivers/platform/x86/think-lmi.c +++ b/drivers/platform/x86/think-lmi.c @@ -14,6 +14,7 @@ #include <linux/acpi.h> #include <linux/errno.h> #include <linux/fs.h> +#include <linux/mutex.h> #include <linux/string.h> #include <linux/types.h> #include <linux/dmi.h> @@ -195,6 +196,7 @@ static const char * const level_options[] = { }; static struct think_lmi tlmi_priv; static struct class *fw_attr_class; +static DEFINE_MUTEX(tlmi_mutex);
/* ------ Utility functions ------------*/ /* Strip out CR if one is present */ @@ -437,6 +439,9 @@ static ssize_t new_password_store(struct kobject *kobj, /* Strip out CR if one is present, setting password won't work if it is present */ strip_cr(new_pwd);
+ /* Use lock in case multiple WMI operations needed */ + mutex_lock(&tlmi_mutex); + pwdlen = strlen(new_pwd); /* pwdlen == 0 is allowed to clear the password */ if (pwdlen && ((pwdlen < setting->minlen) || (pwdlen > setting->maxlen))) { @@ -493,6 +498,7 @@ static ssize_t new_password_store(struct kobject *kobj, kfree(auth_str); } out: + mutex_unlock(&tlmi_mutex); kfree(new_pwd); return ret ?: count; } @@ -982,6 +988,9 @@ static ssize_t current_value_store(struct kobject *kobj, /* Strip out CR if one is present */ strip_cr(new_setting);
+ /* Use lock in case multiple WMI operations needed */ + mutex_lock(&tlmi_mutex); + /* Check if certificate authentication is enabled and active */ if (tlmi_priv.certificate_support && tlmi_priv.pwd_admin->cert_installed) { if (!tlmi_priv.pwd_admin->signature || !tlmi_priv.pwd_admin->save_signature) { @@ -1040,6 +1049,7 @@ static ssize_t current_value_store(struct kobject *kobj, kobject_uevent(&tlmi_priv.class_dev->kobj, KOBJ_CHANGE); } out: + mutex_unlock(&tlmi_mutex); kfree(auth_str); kfree(set_str); kfree(new_setting);