From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751688AbdITGtB (ORCPT ); Wed, 20 Sep 2017 02:49:01 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:33694 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751284AbdITGtA (ORCPT ); Wed, 20 Sep 2017 02:49:00 -0400 X-Google-Smtp-Source: AOwi7QD/vMmtGXvUh6w8tyVV9GDm8jd8i+7PpM4tmZWqqm7t+6nli7aw2mEcnAY6AiyM6mcRuZyWpA== Date: Wed, 20 Sep 2017 15:48:55 +0900 From: Sergey Senozhatsky To: Minchan Kim Cc: Sergey Senozhatsky , Andrew Morton , linux-kernel@vger.kernel.org, Sergey Senozhatsky Subject: Re: [PATCH] zsmalloc: calling zs_map_object() from irq is a bug Message-ID: <20170920064854.GE6298@jagdpanzerIV.localdomain> References: <20170920063941.14662-1-sergey.senozhatsky@gmail.com> <20170920064739.GA11000@bbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170920064739.GA11000@bbox> User-Agent: Mutt/1.9.0 (2017-09-02) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (09/20/17 15:47), Minchan Kim wrote: > On Wed, Sep 20, 2017 at 03:39:41PM +0900, Sergey Senozhatsky wrote: > > Use BUG_ON(in_interrupt()) in zs_map_object(). Calling this > > function from IRQ is a bug, because we use per-CPU mappings > > and interrupt may corrupt those buffers. > > > > Signed-off-by: Sergey Senozhatsky > > IMHO, corruption the buffer would be not enough to be a BUG_ON > which stop the system fully so user loses any chances to shut > down smooth/hunt it down. > > More serious thing of our case is that it can leak other user's > data by overwriting, which is more concern I am thinking now. > > So, > > Acked-by: Minchan Kim thanks. -ss