From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753795AbdJFI7j (ORCPT ); Fri, 6 Oct 2017 04:59:39 -0400 Received: from m12-15.163.com ([220.181.12.15]:45889 "EHLO m12-15.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753663AbdJFI7h (ORCPT ); Fri, 6 Oct 2017 04:59:37 -0400 From: Jia-Ju Bai Subject: [BUG] fs/super: a possible sleep-in-atomic bug in put_super To: viro@zeniv.linux.org.uk, torbjorn.lindh@gopta.se, rgooch@atnf.csiro.au Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Message-ID: <06badf5e-292d-ef63-7499-6888dec1b9b0@163.com> Date: Fri, 6 Oct 2017 16:59:18 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-CM-TRANSID: D8CowAAHvQHoRddZgn6YGw--.15278S2 X-Coremail-Antispam: 1Uf129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7v73 VFW2AGmfu7bjvjm3AaLaJ3UbIYCTnIWIevJa73UjIFyTuYvjxUkVMKDUUUU X-Originating-IP: [183.172.144.119] X-CM-SenderInfo: xedlyx5dmximizq6il2tof0z/xtbBRQhpelO-9VLIwwAAse Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org According to fs/super.c, the kernel may sleep under a spinlock. The function call path is: put_super (acquire the spinlock) __put_super destroy_super list_lru_destroy list_lru_unregister mutex_lock --> may sleep memcg_get_cache_ids down_read --> may sleep This bug is found by my static analysis tool and my code review. Thanks, Jia-Ju Bai