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=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 5C38FC2D0F0 for ; Wed, 1 Apr 2020 16:51:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 062852063A for ; Wed, 1 Apr 2020 16:51:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585759879; bh=CgY4mXuITzuTPiXbroF4GvgpCRhDYaZpzAOZmacCfns=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fVjJ7kkVBUTFM+tH59rOFuC58RCoA5qybnlIfLQ7rJyKR8r1nAnqyJdVjAg52B9ch +BOzFExDr4avei7URMqgsZOtmNoNmQ0EH5bK5IAfioVxJC5RNsQKt5lD6HNjxe3B/9 HnZCw1Ycyp/5DiHgPj+W2b/mtrMKdJm0yW8M2B30= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389216AbgDAQvR (ORCPT ); Wed, 1 Apr 2020 12:51:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:37306 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388258AbgDAQh4 (ORCPT ); Wed, 1 Apr 2020 12:37:56 -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 0663C20772; Wed, 1 Apr 2020 16:37:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585759075; bh=CgY4mXuITzuTPiXbroF4GvgpCRhDYaZpzAOZmacCfns=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L1U1rWfPjmYXvdvTk88MNheWUW35q3Vo62vaEd07v4NBFdFYHTe6+wXaSorVNoRDs W1+2Rtev5QY27EFAz/hZAkvcPN6T1PKYgOKY3wKGhDlkvxekJtmDo37HUylxNa2PqP zBLvbCJhPAwKQqxoT0Az+P0STERtxShm0qomufUU= 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 4.9 068/102] xfrm: policy: Fix doulbe free in xfrm_policy_timer Date: Wed, 1 Apr 2020 18:18:11 +0200 Message-Id: <20200401161544.181086408@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200401161530.451355388@linuxfoundation.org> References: <20200401161530.451355388@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 @@ -336,7 +336,9 @@ 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);