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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 90F9FC433DB for ; Tue, 5 Jan 2021 13:24:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5456A22AAC for ; Tue, 5 Jan 2021 13:24:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728574AbhAENYl (ORCPT ); Tue, 5 Jan 2021 08:24:41 -0500 Received: from mail-m964.mail.126.com ([123.126.96.4]:35110 "EHLO mail-m964.mail.126.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726730AbhAENYj (ORCPT ); Tue, 5 Jan 2021 08:24:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=From:Subject:Date:Message-Id; bh=T+42eSMeQ3OnSshI7/ Fx8CEe5Izt6Qd68TedrfZ4bjo=; b=Tjualv3bJZrImwxvX+zFzSGA2MJajt/BLN EJYS8AtnK4ric4gP31uoSMEXEmyduAuwX2nduSyszzzh4JaIVdbcd0UpqfkGK/aS C8kKJqoXH98DGlmbm30/NgIwI8/m3/hf1xwrV0/5TmERHZLCu+tAMGek0uwgD2hI czrbTBXsA= Received: from localhost.localdomain (unknown [36.112.86.14]) by smtp9 (Coremail) with SMTP id NeRpCgDXnn45aPRfSqJAQg--.24935S2; Tue, 05 Jan 2021 21:23:06 +0800 (CST) From: Defang Bo To: clm@fb.com, josef@toxicpanda.com, dsterba@suse.com Cc: linux-btrfs@vger.kernel.or, linux-kernel@vger.kernel.org, Defang Bo Subject: [PATCH v3] fs/btrfs: avoid null pointer dereference if reloc control has not been initialized Date: Tue, 5 Jan 2021 21:22:58 +0800 Message-Id: <1609852978-2463334-1-git-send-email-bodefang@126.com> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: NeRpCgDXnn45aPRfSqJAQg--.24935S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7trW3Xr1xXrW8Jr4rXF1UWrg_yoW8Gw45pr 43u3WFgF4kJw17Gr4Fka1kCry3Wa1qgryxJwsIvw4xAw1fAF1Sq3yjkF48urW7AFZ8Kw47 Xr4Dt3yUA3WUAwUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0zRMKZZUUUUU= X-Originating-IP: [36.112.86.14] X-CM-SenderInfo: pergvwxdqjqiyswou0bp/1tbi6xoR11pD9edIFwAAsj Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Similar to commmit<389305b2aa68>("btrfs: relocation: Only remove reloc rb_trees if reloc control has been initialized"). It turns out that fs_info::reloc_ctl can be NULL in btrfs_recover_relocation(), as we allocate relocation control after all reloc roots have been verified,so there should be a check for rc to prevent null pointer dereference. ...... Signed-off-by: Defang Bo --- Changes since v2: - Resend this patch with manual reformatted. Changes singe v1: - More accurate description for this patch to describe how the NULL can get there. --- ...... --- fs/btrfs/relocation.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 3602806d71bd..ca035712e08b 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -626,6 +626,9 @@ static int __must_check __add_reloc_root(struct btrfs_root *root) struct mapping_node *node; struct reloc_control *rc = fs_info->reloc_ctl; + if (!rc) + return 0; + node = kmalloc(sizeof(*node), GFP_NOFS); if (!node) return -ENOMEM; @@ -703,6 +706,9 @@ static int __update_reloc_root(struct btrfs_root *root) struct rb_node *rb_node; struct mapping_node *node = NULL; struct reloc_control *rc = fs_info->reloc_ctl; + + if (!rc) + return 0; spin_lock(&rc->reloc_root_tree.lock); rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root, -- 2.7.4