[PATCH] platform/x86: think-lmi: Free system certificate signatures

[Thorsten Blum <thorsten.blum@linux.dev>]

Multi-certificate support also allows the system authentication object
to store ->signature and ->save_signature, which leak when the driver is
removed. Free the signatures to avoid leaking memory.

Fixes: 5dcb5ef12590 ("platform/x86: think-lmi: Multi-certificate support")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 drivers/platform/x86/lenovo/think-lmi.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/platform/x86/lenovo/think-lmi.c b/drivers/platform/x86/lenovo/think-lmi.c
index e215e86e3db7..e3e683bf3469 100644
--- a/drivers/platform/x86/lenovo/think-lmi.c
+++ b/drivers/platform/x86/lenovo/think-lmi.c
@@ -1456,6 +1456,10 @@ static void tlmi_release_attr(void)
 	/* Free up any saved signatures */
 	kfree(tlmi_priv.pwd_admin->signature);
 	kfree(tlmi_priv.pwd_admin->save_signature);
+	if (tlmi_priv.pwd_system) {
+		kfree(tlmi_priv.pwd_system->signature);
+		kfree(tlmi_priv.pwd_system->save_signature);
+	}
 
 	/* Authentication structures */
 	list_for_each_entry_safe(pos, n, &tlmi_priv.authentication_kset->list, entry)