From patchwork Tue Mar 31 08:59:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 228617 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=-6.9 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=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 1A554C2D0EE for ; Tue, 31 Mar 2020 09:16:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E46C821655 for ; Tue, 31 Mar 2020 09:16:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585646219; bh=L+9Vty2YS+wgu/7RjYEPxT1XFKRm43WtauDC7+v9CGQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LykOKu5Tu2fXV+mJnc1RuKhc4mNEQJgC4VnXG2upxk1BCmdPqyRHU4tMrTffDr96i 7Rix5m+ydicV+Unv4TBOVbD4EjcyVV24WsYQKkgdT6W36WmiV0CcWhgtQYQwJ5eU49 XeCBjOE+tFS7UJcnXoglnzNKMEOTaWzg6/I77HZU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731847AbgCaJQ6 (ORCPT ); Tue, 31 Mar 2020 05:16:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:37784 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731993AbgCaJQx (ORCPT ); Tue, 31 Mar 2020 05:16:53 -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 F2CB520787; Tue, 31 Mar 2020 09:16:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585646212; bh=L+9Vty2YS+wgu/7RjYEPxT1XFKRm43WtauDC7+v9CGQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xczGZoLP29hhJ10zjlNsRJFGthTuQ6XQ5SAgGwrrItYT/YUxg/otM/RdtmD5VWNEj oSP77Q2XBtMj2JBp3SEOxjtVEuCxgm/G6lqH49BxRyaNetAD/mtj+rqdjBZYslwUlf j8EtQE995n8P4NOw8AY/woDQMxpR40p/ElpVo548= 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 5.4 118/155] xfrm: policy: Fix doulbe free in xfrm_policy_timer Date: Tue, 31 Mar 2020 10:59:18 +0200 Message-Id: <20200331085431.674272329@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200331085418.274292403@linuxfoundation.org> References: <20200331085418.274292403@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 @@ -431,7 +431,9 @@ 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);