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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=no 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 8108EC43603 for ; Wed, 11 Dec 2019 05:00:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 45DB7214AF for ; Wed, 11 Dec 2019 05:00:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726141AbfLKFAL (ORCPT ); Wed, 11 Dec 2019 00:00:11 -0500 Received: from mx2.suse.de ([195.135.220.15]:45498 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725768AbfLKFAL (ORCPT ); Wed, 11 Dec 2019 00:00:11 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 77B68AE07 for ; Wed, 11 Dec 2019 05:00:09 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH 0/3] btrfs: fixes for relocation to avoid KASAN reports Date: Wed, 11 Dec 2019 13:00:01 +0800 Message-Id: <20191211050004.18414-1-wqu@suse.com> X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Due to commit d2311e698578 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots"), reloc tree lifespan is extended. Although we always set root->reloc_root to NULL before we drop the reloc tree, but that's not multi-core safe since we have no proper memory barrier to ensure other cores can see the same root->reloc_root. The proper root fix should be some proper root refcount, and make btrfs_drop_snapshot() to wait for all other root owner to release the root before dropping it. But for now, let's just check the DEAD_RELOC_ROOT bit before accessing root->reloc_root. Qu Wenruo (3): btrfs: relocation: Fix a KASAN use-after-free bug due to extended reloc tree lifespan btrfs: relocation: Fix KASAN report on create_reloc_tree due to extended reloc tree lifepsan btrfs: relocation: Fix a KASAN report on btrfs_reloc_pre_snapshot() due to extended reloc root lifespan fs/btrfs/relocation.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) -- 2.24.0