From patchwork Wed Apr 1 16:18:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 228328 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 A8495C2D0F3 for ; Wed, 1 Apr 2020 16:52:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D9072063A for ; Wed, 1 Apr 2020 16:52:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585759969; bh=l0tLtA5Kii2quGUsct2DxwWIvKr9B1x+0XIHWHO/7r0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=N6CCsaTBJgfl2fexgYVWleu1deaSSP+9TF57sCscKM0fLXP5gEbxPiRLr4vCKLtcK 4lrJiFio0inGBqMZtr70mSuOzXhCjCKotVntT6J67dZROViDffCk1o6l0FMIHhWdrn GnnpRas1GRsIB/B3nx1iueigInmzUIKmaeu8F30w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388632AbgDAQeQ (ORCPT ); Wed, 1 Apr 2020 12:34:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:60936 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388456AbgDAQeP (ORCPT ); Wed, 1 Apr 2020 12:34:15 -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 C0DE420658; Wed, 1 Apr 2020 16:34:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585758855; bh=l0tLtA5Kii2quGUsct2DxwWIvKr9B1x+0XIHWHO/7r0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KQNfPArmw9ytxaHhcCi9tr6TBC7PTfaNdTJmZW4Au0UFrjy8eo8HRwn8UPXM92Vbg qst8Dk9YKZnrKARQ+k2GFGiZs4C3jdHTfPkuTN8JmiKxyenbjh9wduwf64L+M9FaEF ndpxtU4v/ZgpW+glZUpVjSMhE91dev0zLbizeE7I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, YueHaibing , =?utf-8?q?Timo_Ter=C3=A4s?= , Herbert Xu , Steffen Klassert Subject: [PATCH 4.4 64/91] xfrm: policy: Fix doulbe free in xfrm_policy_timer Date: Wed, 1 Apr 2020 18:18:00 +0200 Message-Id: <20200401161534.840889950@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200401161512.917494101@linuxfoundation.org> References: <20200401161512.917494101@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -330,7 +330,9 @@ 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);