From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fgwmail2.fujitsu.co.jp ([164.71.1.135]:55706 "EHLO fgwmail2.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751676AbaFXHcd (ORCPT ); Tue, 24 Jun 2014 03:32:33 -0400 Received: from kw-mxoi2.gw.nic.fujitsu.com (unknown [10.0.237.143]) by fgwmail2.fujitsu.co.jp (Postfix) with ESMTP id E85D93EE0C8 for ; Tue, 24 Jun 2014 16:32:31 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.nic.fujitsu.com [10.0.50.91]) by kw-mxoi2.gw.nic.fujitsu.com (Postfix) with ESMTP id 076C1AC015A for ; Tue, 24 Jun 2014 16:32:31 +0900 (JST) Received: from g01jpfmpwkw01.exch.g01.fujitsu.local (g01jpfmpwkw01.exch.g01.fujitsu.local [10.0.193.38]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id B4EB91DB8048 for ; Tue, 24 Jun 2014 16:32:30 +0900 (JST) Message-ID: <53A9290D.6090202@jp.fujitsu.com> Date: Tue, 24 Jun 2014 16:30:21 +0900 From: Satoru Takeuchi MIME-Version: 1.0 To: CC: Adam Buchbinder , Subject: [PATCH] Avoid double-free of fs_devices->list. Content-Type: text/plain; charset="ISO-2022-JP" Sender: linux-btrfs-owner@vger.kernel.org List-ID: I found the following patch is insufficient. =============================================================================== commit 6e6b32ddf58db54f714d0f263c2589f4859e8b5e Author: Adam Buchbinder Date: Fri Jun 13 16:43:56 2014 -0700 btrfs-progs: Fix a use-after-free in the volumes code. =============================================================================== "btrfs filesystem show " with this patch causes segmentation fault if "" is a not-mounted Btrfs filesystem. =============================================================================== # ./btrfs filesystem show /dev/sdd1 Label: none uuid: Total devices 1 FS bytes used 112.00KiB devid 1 size 59.12GiB used 2.04GiB path /dev/sdd1 Segmentation fault (core dumped) =============================================================================== It's due to double-free of fs_devices->list as follows. =============================================================================== cmd_show -> list_del(&fs_devices->list) # 1st one. -> btrfs_close_devices(fs_devices) -> list_del(&fs_devices->list) # <- 2nd one introduced at 6e6b32dd. Double-free happens here. =============================================================================== First list_del() can safely be removed because fs_devices->list will be deleted by second one, soon. Signed-off-by: Satoru Takeuchi Cc: Adam Buchbinder --- cmds-filesystem.c | 1 - 1 file changed, 1 deletion(-) diff --git a/cmds-filesystem.c b/cmds-filesystem.c index b1ba508..14cb6e0 100644 --- a/cmds-filesystem.c +++ b/cmds-filesystem.c @@ -716,7 +716,6 @@ devs_only: while (!list_empty(all_uuids)) { fs_devices = list_entry(all_uuids->next, struct btrfs_fs_devices, list); - list_del(&fs_devices->list); btrfs_close_devices(fs_devices); } out: -- 1.9.3