From patchwork Sat Sep 1 10:00:26 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jia-Ju Bai X-Patchwork-Id: 964850 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="L3Fw3YsJ"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 422WvJ0cScz9sBv for ; Sat, 1 Sep 2018 20:00:44 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727335AbeIAOMF (ORCPT ); Sat, 1 Sep 2018 10:12:05 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:36161 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726926AbeIAOMF (ORCPT ); Sat, 1 Sep 2018 10:12:05 -0400 Received: by mail-pl1-f196.google.com with SMTP id e11-v6so6554832plb.3; Sat, 01 Sep 2018 03:00:37 -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=j9cDap1HW/F+JokRW7P2bqq7Yy5kZvZQGSg9p1J42uI=; b=L3Fw3YsJXC/n8P2PW3PjBrwoStt1x6fgHVkM0F9Av6hiSoVwuQqOyEJ0IL9SoDBBK/ 0m6k00MSvwjjaTRSXpnxT8JfmP/cz2Uw91NtyF+qdzja/Y7sdd080n5S8NgwAieEPxxL ZipZun4XnU5y0PO2RW1zmk5VuVeuwRGPnZAmMt7zoUXYVXEZyYzEG8SH09AJkREbkQJh bcBS696OtWvGKFc6TZltqENRU7ZrtiWQTn1mtoJQJUqs3bKlLoG+ur4hLAgwMtIEnFDY VQbvWy6F82P32u5ZIptCv1X1yU27vT5sAB5+NPKH8lARMVwqKZbQbyVqiMQSirShv7xw 6CrA== 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=j9cDap1HW/F+JokRW7P2bqq7Yy5kZvZQGSg9p1J42uI=; b=abf+tW2px/UDKUtU5pjRgQQKx7zHb4uxNLvsxBceL0MXDZH4DtenFpfttrDnKPZUEf izxt3PudHJglmi4PN2CGuhc5pos0wxDrC2xbDC1yNV5/Gg5zCIZj4poeXZfqn1Nf+M4K AF4DTT1y0cxjj5qZufhQVzBFr2e8x7rOa+rCUa5VZLa7oHIb2FiO1jDA3Cfxzsaajilf 1/qpJHIYumJortDo4BxPoohIidcW8pDQ9WQKZo1zfnMiBya/BcT/0CQnTubjVOslIT14 6Z7yQ0LDPKtW+oD/MkAnTdssGZ/O5lzzqNocHE/QXhhjqswXitPoRaAgq/Tld9iPMR1b f3HQ== X-Gm-Message-State: APzg51Bk/OMXxqyaWNuNyx9mwxxUmJwhd7TKHKz9xPtKGrajxl6BrFjW YBS/Fq9yzqN+hnOgCcPErhQ= X-Google-Smtp-Source: ANB0Vdb++XgYWX0KBLy1cz93Yrq7wza61arVnHsaHBg4guGBpSyF8csykSBCThxrzvlPQQekrGkKxg== X-Received: by 2002:a17:902:a5cc:: with SMTP id t12-v6mr19135616plq.6.1535796036964; Sat, 01 Sep 2018 03:00:36 -0700 (PDT) Received: from localhost.localdomain ([2402:f000:1:4414:2913:cd09:aee0:380]) by smtp.gmail.com with ESMTPSA id x3-v6sm14413798pgv.61.2018.09.01.03.00.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 01 Sep 2018 03:00:36 -0700 (PDT) From: Jia-Ju Bai To: davem@davemloft.net, ktkhai@virtuozzo.com, viro@zeniv.linux.org.uk, adobriyan@gmail.com, dvlasenk@redhat.com, xiyou.wangcong@gmail.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] net: scm: Fix a possible sleep-in-atomic-context bug in scm_fp_copy() Date: Sat, 1 Sep 2018 18:00:26 +0800 Message-Id: <20180901100026.16956-1-baijiaju1990@gmail.com> X-Mailer: git-send-email 2.17.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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] kmalloc(GFP_KERNEL) net/core/scm.c, 85: kmalloc in scm_fp_copy net/core/scm.c, 161: scm_fp_copy in __scm_send ./include/net/scm.h, 88: __scm_send in scm_send net/unix/af_unix.c, 1600: scm_send in maybe_init_creds net/unix/af_unix.c, 1983: maybe_init_creds in unix_stream_sendpage net/unix/af_unix.c, 1973: spin_lock in unix_stream_sendpage To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC. This bug is found by my static analysis tool DSAC. Signed-off-by: Jia-Ju Bai --- net/core/scm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/scm.c b/net/core/scm.c index b1ff8a441748..49548f81c45b 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -82,7 +82,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp) if (!fpl) { - fpl = kmalloc(sizeof(struct scm_fp_list), GFP_KERNEL); + fpl = kmalloc(sizeof(struct scm_fp_list), GFP_ATOMIC); if (!fpl) return -ENOMEM; *fplp = fpl;