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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B711BC0015E for ; Wed, 9 Aug 2023 11:40:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234186AbjHILkJ (ORCPT ); Wed, 9 Aug 2023 07:40:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234191AbjHILkI (ORCPT ); Wed, 9 Aug 2023 07:40:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F2121FD7 for ; Wed, 9 Aug 2023 04:40:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E3DA463624 for ; Wed, 9 Aug 2023 11:40:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0017AC433C7; Wed, 9 Aug 2023 11:40:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691581207; bh=j26lokBMULN6zdeY34JL6al1/0G0LeGP6+IVMDtzzpQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=plOodmoZoHTTymOnu40vucJi6OMRA0dC223Cb3lCvx67SJzMaucnuepQoz8GGsSei Gr1fOrHHUMvuI+ztyY6sK9C97MKr1rbbrIXW6s1BlcX6VsKDTydEms0SJAqElldoCq sGlhjKygNq7fSHAwAPGEKgYBcW3upuMTjIgM5lFM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, valis , M A Ramdhan , Jamal Hadi Salim , Victor Nogueira , Pedro Tammela , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.10 143/201] net/sched: cls_u32: No longer copy tcf_result on update to avoid use-after-free Date: Wed, 9 Aug 2023 12:42:25 +0200 Message-ID: <20230809103648.513119921@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103643.799166053@linuxfoundation.org> References: <20230809103643.799166053@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: valis [ Upstream commit 3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81 ] When u32_change() is called on an existing filter, the whole tcf_result struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcf_unbind_filter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free. Fix this by no longer copying the tcf_result struct from the old filter. Fixes: de5df63228fc ("net: sched: cls_u32 changes to knode must appear atomic to readers") Reported-by: valis Reported-by: M A Ramdhan Signed-off-by: valis Signed-off-by: Jamal Hadi Salim Reviewed-by: Victor Nogueira Reviewed-by: Pedro Tammela Reviewed-by: M A Ramdhan Link: https://lore.kernel.org/r/20230729123202.72406-2-jhs@mojatatu.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sched/cls_u32.c | 1 - 1 file changed, 1 deletion(-) diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index 04e933530cade..b2d2ba561eba1 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -812,7 +812,6 @@ static struct tc_u_knode *u32_init_knode(struct net *net, struct tcf_proto *tp, new->ifindex = n->ifindex; new->fshift = n->fshift; - new->res = n->res; new->flags = n->flags; RCU_INIT_POINTER(new->ht_down, ht); -- 2.40.1