optee: Fix memory leak when failing to register shm pages

Free the previously allocated pages when we encounter an error condition
while attempting to register the pages with the secure world.

Fixes: a249dd200d ("tee: optee: Fix dynamic shm pool allocations")
Fixes: 5a769f6ff4 ("optee: Fix multi page dynamic shm pool alloc")
Cc: [email protected]
Signed-off-by: Tyler Hicks <[email protected]>
Reviewed-by: Jens Wiklander <[email protected]>
Reviewed-by: Sumit Garg <[email protected]>
Signed-off-by: Jens Wiklander <[email protected]>

drivers/tee/optee/shm_pool.c

@@ -32,8 +32,10 @@ static int pool_op_alloc(struct tee_shm_pool_mgr *poolm,
 		struct page **pages;
 
 		pages = kcalloc(nr_pages, sizeof(pages), GFP_KERNEL);
-		if (!pages)
-			return -ENOMEM;
+		if (!pages) {
+			rc = -ENOMEM;
+			goto err;
+		}
 
 		for (i = 0; i < nr_pages; i++) {
 			pages[i] = page;
@@ -44,8 +46,14 @@ static int pool_op_alloc(struct tee_shm_pool_mgr *poolm,
 		rc = optee_shm_register(shm->ctx, shm, pages, nr_pages,
 					(unsigned long)shm->kaddr);
 		kfree(pages);
+		if (rc)
+			goto err;
 	}
 
+	return 0;
+
+err:
+	__free_pages(page, order);
 	return rc;
 }