Received: by 2002:a17:90a:1609:0:0:0:0 with SMTP id n9csp848912pja; Wed, 1 Apr 2020 09:48:02 -0700 (PDT) X-Google-Smtp-Source: ADFU+vsO9ma/1/t5ebuP2WKddSMBegBzPQ3/k+Fh6wgv6gQpanKFzi2k3xoyC5TfyfgpSEWUVkg9 X-Received: by 2002:a9d:2dc1:: with SMTP id g59mr7464182otb.90.1585759682194; Wed, 01 Apr 2020 09:48:02 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1585759682; cv=none; d=google.com; s=arc-20160816; b=LtUCfvosE7S4m5GX4TxlmmaF9G3bUvx5xFI1GNugCng9/qepShlRgKKSfkpe61Mlgc Vk7Od8wBlqZeRRUPFg1EypG7yNujv4M+DE4uzjtNZckoNcdnSsevmP7sjnRknCy8FhS7 moicNwHWVUEkkHJxJWm2X1M7x0xjgf5jCL7yvR/lQ/7SO1YAqTxlV4i6KOsGQciidvj9 i03yKoqh/b405qSgSlU93FZ3XBBo2EraYdIOg50Ox30sV67H1q6mi1FduLKm/1XFgd2m 3lZZVSomTmZDcIPgD9yFSefcj3+wVYU/n7/2oVeI5yTT31z3NM1sIRbbEh2jZoAB6JY6 bY/g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=vcwCW0gVAaPamHD5cTEj0Pu8egTPc7AamjaSfmq0fmo=; b=ArMnHYGSHR1bI04AXGC5TR845RxfCVD06Y2gyFuo1OzD2+a4VmgJxba4x4SoldUziM tjJ9lmfTHuSpgtCf3Mmj9yc19GrAdNF6vTnbdRHfC/9dHRFLui7Qih+yuie/InhinmDS LiNtx7E12HrjspRc9DVBeXZK/ER3/W+nMZrusSApI17cMHU2cKY96836OJGCxRY2purJ NlVMhcpUtWkRhE4eXwMahzGCWaWBndovQpeaqUzG66OWOXCT1zo2vhlHkEeCGw/J6qKE u0JdRc8jxzllA3qg5xMa4wobKkUwiIkA1BNShY/IMG69fZCKKcynE1UyG3RhPkpXxO8+ nn5A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=V03KuGmV; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id y7si1171322ote.303.2020.04.01.09.47.49; Wed, 01 Apr 2020 09:48:02 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=V03KuGmV; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389402AbgDAQpg (ORCPT + 99 others); Wed, 1 Apr 2020 12:45:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:46782 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389673AbgDAQpc (ORCPT ); Wed, 1 Apr 2020 12:45:32 -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 6863B206E9; Wed, 1 Apr 2020 16:45:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585759530; bh=Zb7mzK58iMv/f7Em5bU4RrsDulMKPlH00x6d3hoe/4s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V03KuGmVyUzxkPrhKVi6WUHd1GrOzGSEdBwPfvKXvd6JzDjZ+jWwEbWsQU4kdZX7V lI1o0JB6/VM3cxhmZeZArqa/W8DZZabhKKywutk6X8U8pI4Av984TTQGFImjDSFu0D wicv7KFjavUQwoVy4EWMjzRjNBuWfzqVjOERnlv0= 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 4.14 108/148] xfrm: policy: Fix doulbe free in xfrm_policy_timer Date: Wed, 1 Apr 2020 18:18:20 +0200 Message-Id: <20200401161602.993586076@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200401161552.245876366@linuxfoundation.org> References: <20200401161552.245876366@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 @@ -301,7 +301,9 @@ 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);