Merge tag 'amdtee-fix-for-v6.3' of https://git.linaro.org/people/jens.wiklander/linux-tee into soc-fixes

AMDTEE fix race condition in amdtee_open_session()

* tag 'amdtee-fix-for-v6.3' of https://git.linaro.org/people/jens.wiklander/linux-tee:
  tee: amdtee: fix race condition in amdtee_open_session

Link: https://lore.kernel.org/r/Y/5ZGX0lSTnZz27E@rayden
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Author: arndb

drivers/tee/amdtee/core.c

@@ -267,35 +267,34 @@ int amdtee_open_session(struct tee_context *ctx,
 		goto out;
 	}
 
+	/* Open session with loaded TA */
+	handle_open_session(arg, &session_info, param);
+	if (arg->ret != TEEC_SUCCESS) {
+		pr_err("open_session failed %d\n", arg->ret);
+		handle_unload_ta(ta_handle);
+		kref_put(&sess->refcount, destroy_session);
+		goto out;
+	}
+
 	/* Find an empty session index for the given TA */
 	spin_lock(&sess->lock);
 	i = find_first_zero_bit(sess->sess_mask, TEE_NUM_SESSIONS);
-	if (i < TEE_NUM_SESSIONS)
+	if (i < TEE_NUM_SESSIONS) {
+		sess->session_info[i] = session_info;
+		set_session_id(ta_handle, i, &arg->session);
 		set_bit(i, sess->sess_mask);
+	}
 	spin_unlock(&sess->lock);
 
 	if (i >= TEE_NUM_SESSIONS) {
 		pr_err("reached maximum session count %d\n", TEE_NUM_SESSIONS);
+		handle_close_session(ta_handle, session_info);
 		handle_unload_ta(ta_handle);
 		kref_put(&sess->refcount, destroy_session);
 		rc = -ENOMEM;
 		goto out;
 	}
 
-	/* Open session with loaded TA */
-	handle_open_session(arg, &session_info, param);
-	if (arg->ret != TEEC_SUCCESS) {
-		pr_err("open_session failed %d\n", arg->ret);
-		spin_lock(&sess->lock);
-		clear_bit(i, sess->sess_mask);
-		spin_unlock(&sess->lock);
-		handle_unload_ta(ta_handle);
-		kref_put(&sess->refcount, destroy_session);
-		goto out;
-	}
-
-	sess->session_info[i] = session_info;
-	set_session_id(ta_handle, i, &arg->session);
 out:
 	free_pages((u64)ta, get_order(ta_size));
 	return rc;