--- x/kernel/time/posix-clock.c
+++ y/kernel/time/posix-clock.c
@@ -153,8 +153,10 @@ static int posix_clock_release(struct in
 		return -ENODEV;
 	clk = pccontext->clk;
 
+	down_write(&clk->rwsem);
 	if (clk->ops.release)
 		err = clk->ops.release(pccontext);
+	up_write(&clk->rwsem);
 
 	put_device(clk->dev);