LSM: Check for NULL cred-security on free
From: Casey Schaufler <casey@schaufler-ca.com>
Check that the cred security blob has been set before trying
to clean it up. There is a case during credential initialization
that could result in this.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
Reported-by: syzbot+69ca07954461f189e808@syzkaller.appspotmail.com
diff --git a/security/security.c b/security/security.c
index f1b8d25..55bc490 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1027,6 +1027,13 @@
void security_cred_free(struct cred *cred)
{
+ /*
+ * There is a failure case in prepare_creds() that
+ * may result in a call here with ->security being NULL.
+ */
+ if (unlikely(cred->security == NULL))
+ return;
+
call_void_hook(cred_free, cred);
}
