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 CCFE2C433F5 for ; Sat, 1 Sep 2018 11:20:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D8F72083C for ; Sat, 1 Sep 2018 11:20:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ere6ehCl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D8F72083C 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 S1727261AbeIAPbv (ORCPT ); Sat, 1 Sep 2018 11:31:51 -0400 Received: from mail-pl1-f194.google.com ([209.85.214.194]:39233 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725973AbeIAPbv (ORCPT ); Sat, 1 Sep 2018 11:31:51 -0400 Received: by mail-pl1-f194.google.com with SMTP id w14-v6so6599846plp.6; Sat, 01 Sep 2018 04:20:10 -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=zpXmcdUsbwj5gElJZ0iWkZ7QP4qhOecXqtvjxnmtywM=; b=ere6ehClkDycpxO31dp3Q8cibj10r8TZhkL0+PrMRV1mGwCGLCVDFMjVWUDdlvDTby yLpIBCxg+Chcsrhf9KfyVREFy4Qx7oNbSqN0C2mv88IsPPtsyOpNdfN1Wj42+hxXJ5zB raA2TyyojjG0M9fCGdnYxOxUdX3tA78PsIVzwU9atNQOU5FFcrS5hVOhRfGQXLiW/c7x v2JE67Ha73eEJ3tqpaRU6IupAB0WrP0W6i7ri/OKziO3MiGlWQnfP62DJknAaOW8F3cl afRDNdalhiELY3X6jD4qZDBVTLpi4ZezUar8o9ni1tx3wZnv/TcMlf09qHu2MKKVvxEY CPkA== 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=zpXmcdUsbwj5gElJZ0iWkZ7QP4qhOecXqtvjxnmtywM=; b=EN3q3SjK4WBIxXyVxGuhZBf6N/FqPOpiq0iaBKQdDsN7h9ZJiIG7YsjMZVvegtB/Os c2gLQYOhdHuv3jR0GfTpchDTX3PQ1ZDckqfm67YgGkaEUiDR2BI78pJnI+bMpW+c/31c qSvWCCZySiAdt9PVOycKbdJbc6o1XNKgzShr49Tqo0YqjlgnlRkTID+rq2YQduSbnLg+ WmZSpNoR3woAS7UZdemKhLDCAAxRaUIeIoDut4CLG34soFpVucj0GnrFZBb2p2zbD8yW uM1B4PKIHdYhbTPvWj72jji7+//bw9O+dG5RsiIcLDaaXDQazF6Gyg/acB9UtGL4i66I sXiQ== X-Gm-Message-State: APzg51DlEfit4KHQrj2p9F80aKntsdr37WnXtcTHvVEllg22fiooWKAF A7jErfKTelbKzmZqv/4AEyY= X-Google-Smtp-Source: ANB0VdZlroPkWsMeYctXrzFKEpQUNKjKWpNuf74KaNOHzWWYOvhcyO9g749TP8KYNWCxSpropH4f1g== X-Received: by 2002:a17:902:1ab:: with SMTP id b40-v6mr20057247plb.55.1535800810115; Sat, 01 Sep 2018 04:20:10 -0700 (PDT) Received: from localhost.localdomain ([2402:f000:1:4414:2913:cd09:aee0:380]) by smtp.gmail.com with ESMTPSA id p26-v6sm6599983pgn.64.2018.09.01.04.20.07 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 01 Sep 2018 04:20:09 -0700 (PDT) From: Jia-Ju Bai To: davem@davemloft.net, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH] net: ipv6: route: Fix a sleep-in-atomic-context bug in ip6_convert_metrics() Date: Sat, 1 Sep 2018 19:19:58 +0800 Message-Id: <20180901111958.26529-1-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] kzalloc(GFP_KERNEL) net/ipv6/route.c, 2430: kzalloc in ip6_convert_metrics net/ipv6/route.c, 2890: ip6_convert_metrics in ip6_route_add net/ipv6/addrconf.c, 2322: ip6_route_add in addrconf_prefix_route net/ipv6/addrconf.c, 3331: addrconf_prefix_route in fixup_permanent_addr net/ipv6/addrconf.c, 3354: fixup_permanent_addr in addrconf_permanent_addr net/ipv6/addrconf.c, 3358: _raw_write_lock_bh in addrconf_permanent_addr 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/ipv6/route.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index ec18b3ce8b6d..d15e72def7c1 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2742,7 +2742,7 @@ static int ip6_convert_metrics(struct net *net, struct fib6_info *rt, if (!cfg->fc_mx) return 0; - p = kzalloc(sizeof(*rt->fib6_metrics), GFP_KERNEL); + p = kzalloc(sizeof(*rt->fib6_metrics), GFP_ATOMIC); if (unlikely(!p)) return -ENOMEM; -- 2.17.0