From patchwork Mon May 4 17:57:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 226351 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, 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 C2A82C47257 for ; Mon, 4 May 2020 18:13:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A634320663 for ; Mon, 4 May 2020 18:13:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588616005; bh=+uHnYeckTZ/b/1RoIw0t+qHts3oKfYXWET/DSt23zbY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=u3y4uWmQFecn5hK9YCPZzM++o6ED4Uz+wr9Kj9uLGPvUpD8LPsxuhu912YAsS3O7W Xk+k1hO9Y5ZRXlfR+PD80KN22L7AUVCfTtq87PMiW4bCVW5l7F+twqvIL+u/P83pvD 1FAqSKk79WmFOvuwwUIa5v7jP4Sw3w5JK1UyeHdI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731832AbgEDSNY (ORCPT ); Mon, 4 May 2020 14:13:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:57182 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731168AbgEDSBe (ORCPT ); Mon, 4 May 2020 14:01:34 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 165E520707; Mon, 4 May 2020 18:01:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588615294; bh=+uHnYeckTZ/b/1RoIw0t+qHts3oKfYXWET/DSt23zbY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ui7iHAAyYSGP4SBB3EDXNbWP7L7nwG/v96SJZ6RlvrJJNGVkQb4vieC61zzrfiXBZ yiWZezlmEC26Q4cGrzAnsswwlSdn/Hkf7ofOSG98+h0qubkoU2jIbPqzwk6h9F3RjV JSm4tSVW0pYDHnkf7C3Y2zrH9Q0jcvPn/g9DB0n4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiyu Yang , Xin Tan , David Sterba Subject: [PATCH 4.19 05/37] btrfs: fix block group leak when removing fails Date: Mon, 4 May 2020 19:57:18 +0200 Message-Id: <20200504165449.199649237@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200504165448.264746645@linuxfoundation.org> References: <20200504165448.264746645@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xiyu Yang commit f6033c5e333238f299c3ae03fac8cc1365b23b77 upstream. btrfs_remove_block_group() invokes btrfs_lookup_block_group(), which returns a local reference of the block group that contains the given bytenr to "block_group" with increased refcount. When btrfs_remove_block_group() returns, "block_group" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in several exception handling paths of btrfs_remove_block_group(). When those error scenarios occur such as btrfs_alloc_path() returns NULL, the function forgets to decrease its refcnt increased by btrfs_lookup_block_group() and will cause a refcnt leak. Fix this issue by jumping to "out_put_group" label and calling btrfs_put_block_group() when those error scenarios occur. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/extent-tree.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -10286,7 +10286,7 @@ int btrfs_remove_block_group(struct btrf path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; - goto out; + goto out_put_group; } /* @@ -10323,7 +10323,7 @@ int btrfs_remove_block_group(struct btrf ret = btrfs_orphan_add(trans, BTRFS_I(inode)); if (ret) { btrfs_add_delayed_iput(inode); - goto out; + goto out_put_group; } clear_nlink(inode); /* One for the block groups ref */ @@ -10346,13 +10346,13 @@ int btrfs_remove_block_group(struct btrf ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1); if (ret < 0) - goto out; + goto out_put_group; if (ret > 0) btrfs_release_path(path); if (ret == 0) { ret = btrfs_del_item(trans, tree_root, path); if (ret) - goto out; + goto out_put_group; btrfs_release_path(path); } @@ -10494,9 +10494,9 @@ int btrfs_remove_block_group(struct btrf ret = remove_block_group_free_space(trans, block_group); if (ret) - goto out; + goto out_put_group; - btrfs_put_block_group(block_group); + /* Once for the block groups rbtree */ btrfs_put_block_group(block_group); ret = btrfs_search_slot(trans, root, &key, path, -1, 1); @@ -10524,6 +10524,10 @@ int btrfs_remove_block_group(struct btrf /* once for the tree */ free_extent_map(em); } + +out_put_group: + /* Once for the lookup reference */ + btrfs_put_block_group(block_group); out: btrfs_free_path(path); return ret;