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 E75B9C001B0 for ; Wed, 9 Aug 2023 11:24:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233673AbjHILY5 (ORCPT ); Wed, 9 Aug 2023 07:24:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45784 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233674AbjHILY4 (ORCPT ); Wed, 9 Aug 2023 07:24:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9420AED for ; Wed, 9 Aug 2023 04:24:56 -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 344FF6324F for ; Wed, 9 Aug 2023 11:24:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45512C433C9; Wed, 9 Aug 2023 11:24:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691580295; bh=V5wxOqbu7K5ExT1f4cIWnFpO2Bns+3jY0dmR1G6F2Lw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bxBY6mtr1ogb11DGxp1g6pwodm/3uFIAUUnYQQTxFBF7eBzZM98TLJVVBxS7gu7ht 4m6XRhgw37cuymbhgJpH4Fc4hsQhKAsRDm8bO0SluVmiMp7aLU9H46f0o4XSBoUr4p 4kPc85CQwUuXqIfeC+eJ1hMotHNlX/7OpY/s/IxA= 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 4.19 296/323] net/sched: cls_u32: No longer copy tcf_result on update to avoid use-after-free Date: Wed, 9 Aug 2023 12:42:14 +0200 Message-ID: <20230809103711.614578907@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103658.104386911@linuxfoundation.org> References: <20230809103658.104386911@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 5e052c7342b9f..1e71ff093c91d 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -879,7 +879,6 @@ static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp, new->ifindex = n->ifindex; #endif new->fshift = n->fshift; - new->res = n->res; new->flags = n->flags; RCU_INIT_POINTER(new->ht_down, ht); -- 2.40.1