From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1820BC433B4 for ; Fri, 16 Apr 2021 18:20:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF4496023C for ; Fri, 16 Apr 2021 18:20:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244668AbhDPSVC (ORCPT ); Fri, 16 Apr 2021 14:21:02 -0400 Received: from mx2.suse.de ([195.135.220.15]:58320 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236112AbhDPSU7 (ORCPT ); Fri, 16 Apr 2021 14:20:59 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id D9476B061; Fri, 16 Apr 2021 18:20:33 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 14CC5DA790; Fri, 16 Apr 2021 20:18:17 +0200 (CEST) Date: Fri, 16 Apr 2021 20:18:16 +0200 From: David Sterba To: Nikolay Borisov Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH] btrfs-progs: Fix null pointer deref in balance_level Message-ID: <20210416181816.GJ7604@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Nikolay Borisov , linux-btrfs@vger.kernel.org References: <20210406135503.164590-1-nborisov@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210406135503.164590-1-nborisov@suse.com> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Tue, Apr 06, 2021 at 04:55:03PM +0300, Nikolay Borisov wrote: > In case the right buffer is emptied it's first set to null and > subsequently it's dereferenced to get its size to pass to root_sub_used. > This naturally leads to a null pointer dereference. The correct thing > to do is to pass the stashed right->len in "blocksize". > > Fixes #296 I'm using the "Issue: #123" format for that. > Signed-off-by: Nikolay Borisov Added to devel, thanks.