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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 C5582C2D0F3 for ; Wed, 1 Apr 2020 16:26:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7503820BED for ; Wed, 1 Apr 2020 16:26:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585758383; bh=nl2ZN3Pi4tmBVjj446X5Z8x61Da2qbmYcHGQwxUDZvY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=m/IPy+0QlBttz4b3YByHuURRYfiICwhqXkt2rra7NjBWXSGhHAL/+7Yr85ZQN6Z7Y FDHHW3gCGGNSYEnZKIcviX1jLXnSO11/hwNpgykzGao/Q/XBgwbeKoN0Pgw/MWqQGh /S2/+RYEIo6DlO3HGJEEOODGetAi11pOxSikfOv8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387888AbgDAQ0W (ORCPT ); Wed, 1 Apr 2020 12:26:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:50740 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732342AbgDAQ0R (ORCPT ); Wed, 1 Apr 2020 12:26:17 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5041520857; Wed, 1 Apr 2020 16:26:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585758376; bh=nl2ZN3Pi4tmBVjj446X5Z8x61Da2qbmYcHGQwxUDZvY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IhJp0mmIaOUJhyWYgW0mBG7I5fHfJSXFeL1+OfaIN3bQcyysiuVYwjxxINbpxa2kU SnoP0elvhrIYMIOekBCLWuhPDZ4TkWyKLyxwTgtV5/KwBSVtoX7luqjqSA7krLPwwg ARumxNsbwCYe02CNXgrKzjpiVgF55kDX8fulTLu8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, YueHaibing , =?UTF-8?q?Timo=20Ter=C3=A4s?= , Herbert Xu , Steffen Klassert Subject: [PATCH 4.19 070/116] xfrm: policy: Fix doulbe free in xfrm_policy_timer Date: Wed, 1 Apr 2020 18:17:26 +0200 Message-Id: <20200401161552.010151210@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200401161542.669484650@linuxfoundation.org> References: <20200401161542.669484650@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: YueHaibing commit 4c59406ed00379c8663f8663d82b2537467ce9d7 upstream. After xfrm_add_policy add a policy, its ref is 2, then xfrm_policy_timer read_lock xp->walk.dead is 0 .... mod_timer() xfrm_policy_kill policy->walk.dead = 1 .... del_timer(&policy->timer) xfrm_pol_put //ref is 1 xfrm_pol_put //ref is 0 xfrm_policy_destroy call_rcu xfrm_pol_hold //ref is 1 read_unlock xfrm_pol_put //ref is 0 xfrm_policy_destroy call_rcu xfrm_policy_destroy is called twice, which may leads to double free. Call Trace: RIP: 0010:refcount_warn_saturate+0x161/0x210 ... xfrm_policy_timer+0x522/0x600 call_timer_fn+0x1b3/0x5e0 ? __xfrm_decode_session+0x2990/0x2990 ? msleep+0xb0/0xb0 ? _raw_spin_unlock_irq+0x24/0x40 ? __xfrm_decode_session+0x2990/0x2990 ? __xfrm_decode_session+0x2990/0x2990 run_timer_softirq+0x5c5/0x10e0 Fix this by use write_lock_bh in xfrm_policy_kill. Fixes: ea2dea9dacc2 ("xfrm: remove policy lock when accessing policy->walk.dead") Signed-off-by: YueHaibing Acked-by: Timo Teräs Acked-by: Herbert Xu Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman --- net/xfrm/xfrm_policy.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -309,7 +309,9 @@ EXPORT_SYMBOL(xfrm_policy_destroy); static void xfrm_policy_kill(struct xfrm_policy *policy) { + write_lock_bh(&policy->lock); policy->walk.dead = 1; + write_unlock_bh(&policy->lock); atomic_inc(&policy->genid);