diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 12dcd2e737c3..c75eafe872cc 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -1305,10 +1305,12 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl,  u32 kernel,
 	}
 
 	if (err == -ERESTARTSYS) {
+		spin_lock(&fl->lock);
 		list_for_each_entry_safe(buf, b, &fl->mmaps, node) {
 			list_del(&buf->node);
 			list_add_tail(&buf->node, &fl->cctx->invoke_interrupted_mmaps);
 		}
+		spin_unlock(&fl->lock);
 	}
 
 	if (err)