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=-2.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 94A92C433F5 for ; Sat, 1 Sep 2018 11:25:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2239120835 for ; Sat, 1 Sep 2018 11:25:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="beplJqcd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2239120835 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727354AbeIAPhU (ORCPT ); Sat, 1 Sep 2018 11:37:20 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:44125 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725973AbeIAPhU (ORCPT ); Sat, 1 Sep 2018 11:37:20 -0400 Received: by mail-pl1-f196.google.com with SMTP id ba4-v6so6593802plb.11 for ; Sat, 01 Sep 2018 04:25:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=25NOX6BG+WBi0jAWQa6TAWi+GP3D18WHlD7cIG/N4+I=; b=beplJqcdDJXn8bSw+iWasasu3zztRvirop8+N8Amd3tGp4UJXcuocjsVHeM56sXVzr vu+Gq6bd41MJsCfPR4S+ZIG4dpjkq8PwuQkOZV/yrE/yix3L5lCk+9D5q1VtKLnbRwob IaTYr15ASY/6osI3VJObLSwbrmojWJWA5BMljxQ/tTUQZGbd00XCx2jHlK651xFpgpMr qHTas2LJTalOSH3gNj41WVqxkSAVbx0d/88EsitiQLP7k0M74AqdCYy1uQVnKR1BWntG fRcRBzmzEnqPiJP8o5U/Hnujq1BRGKs1FzCEkGaafYaOVDM9kQur+RJcbOFY+1HYkOnx 6IuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=25NOX6BG+WBi0jAWQa6TAWi+GP3D18WHlD7cIG/N4+I=; b=jFj4emJ+sJQUsEjem+2nnpsCA710+yRxMah6ZlTJ2171vfOz3bUOU7mCTPg4E4sdtM FtRYS/a0ZBFOx4dzHyLXsFECDYgBIFlba8Fz1A/BiN0aY8NAXjhbaqTNIplTi9AYixgM WzONoiZIECx6hOtUXtpKqyZWAdb5QGamZC9JZZE1rhxiScAIxKD+uhJXQzlFrFjBt4VU H32dSxwjdSAWSq/GNOGBpQzcn/bWWQs7koYocoEjI0FkPAV2ArlY1jhkr7eZ5ydnElae taVwxZHwI3aN8GFaGwe8WqAFNTkDxxYoqBe/AGC9oqdcSzOx3yJHlSk7cb2J8P55jRnK M9Iw== X-Gm-Message-State: APzg51BqXCdpY/9xuwPVKGM7Eplc+60mV0xOnaYMI5LbIFDbUMtsv680 xKg+Zu3ckVlcdvC/OB9NPa0= X-Google-Smtp-Source: ANB0VdaacDjilV76LbW6s/9QexkiQ9JJXKNQ3I5YCwlEeIkpns4KKBvKYtUTqEIf42IxPQtJj93f8Q== X-Received: by 2002:a17:902:d808:: with SMTP id a8-v6mr19619730plz.68.1535801138543; Sat, 01 Sep 2018 04:25:38 -0700 (PDT) Received: from localhost.localdomain ([2402:f000:1:4414:2913:cd09:aee0:380]) by smtp.gmail.com with ESMTPSA id p2-v6sm14343785pgv.21.2018.09.01.04.25.36 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 01 Sep 2018 04:25:38 -0700 (PDT) From: Jia-Ju Bai To: mark@fasheh.com, jlbec@evilplan.org Cc: ocfs2-devel@oss.oracle.com, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] fs: ocfs2: dlm: Fix a sleep-in-atomic-context bug in dlm_print_one_mle() Date: Sat, 1 Sep 2018 19:25:28 +0800 Message-Id: <20180901112528.27025-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The kernel module may sleep with holding a spinlock. The function call paths (from bottom to top) in Linux-4.16 are: [FUNC] get_zeroed_page(GFP_NOFS) fs/ocfs2/dlm/dlmdebug.c, 332: get_zeroed_page in dlm_print_one_mle fs/ocfs2/dlm/dlmmaster.c, 240: dlm_print_one_mle in __dlm_put_mle fs/ocfs2/dlm/dlmmaster.c, 255: __dlm_put_mle in dlm_put_mle fs/ocfs2/dlm/dlmmaster.c, 254: spin_lock in dlm_put_ml [FUNC] get_zeroed_page(GFP_NOFS) fs/ocfs2/dlm/dlmdebug.c, 332: get_zeroed_page in dlm_print_one_mle fs/ocfs2/dlm/dlmmaster.c, 240: dlm_print_one_mle in __dlm_put_mle fs/ocfs2/dlm/dlmmaster.c, 222: __dlm_put_mle in dlm_put_mle_inuse fs/ocfs2/dlm/dlmmaster.c, 219: spin_lock in dlm_put_mle_inuse To fix this bug, GFP_NOFS is replaced with GFP_ATOMIC. This bug is found by my static analysis tool DSAC. Signed-off-by: Jia-Ju Bai --- fs/ocfs2/dlm/dlmdebug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c index 9b984cae4c4e..1d6dc8422899 100644 --- a/fs/ocfs2/dlm/dlmdebug.c +++ b/fs/ocfs2/dlm/dlmdebug.c @@ -329,7 +329,7 @@ void dlm_print_one_mle(struct dlm_master_list_entry *mle) { char *buf; - buf = (char *) get_zeroed_page(GFP_NOFS); + buf = (char *) get_zeroed_page(GFP_ATOMIC); if (buf) { dump_mle(mle, buf, PAGE_SIZE - 1); free_page((unsigned long)buf); -- 2.17.0