From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754818AbaI2Upp (ORCPT ); Mon, 29 Sep 2014 16:45:45 -0400 Received: from shards.monkeyblade.net ([149.20.54.216]:33949 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751898AbaI2Upo (ORCPT ); Mon, 29 Sep 2014 16:45:44 -0400 Date: Mon, 29 Sep 2014 16:45:41 -0400 (EDT) Message-Id: <20140929.164541.20059477388052953.davem@davemloft.net> To: sasha.levin@oracle.com Cc: acme@ghostprotocols.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] net: llc: check for device before dereferencing From: David Miller In-Reply-To: <1411782103-3059-1-git-send-email-sasha.levin@oracle.com> References: <1411782103-3059-1-git-send-email-sasha.levin@oracle.com> X-Mailer: Mew version 6.5 on Emacs 24.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.7 (shards.monkeyblade.net [149.20.54.216]); Mon, 29 Sep 2014 13:45:43 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sasha Levin Date: Fri, 26 Sep 2014 21:41:43 -0400 > llc_ui_sendmsg would not make sure that a device indeed exists before > dereferencing it. This caused a user triggerable NULL ptr deref: ... > Signed-off-by: Sasha Levin The bug is real, but I don't think the fix is in the correct spot. The real problem seems to be that the guard for calling llc_ui_autobind() is inaccurate. Fix that and there will always be a proper llc->dev attached at this location.