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 12B3CC6FA86 for ; Tue, 6 Sep 2022 13:43:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234139AbiIFNnF (ORCPT ); Tue, 6 Sep 2022 09:43:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40144 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234173AbiIFNlY (ORCPT ); Tue, 6 Sep 2022 09:41:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F6C265B6; Tue, 6 Sep 2022 06:37:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 92EB161522; Tue, 6 Sep 2022 13:37:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9FCEEC433C1; Tue, 6 Sep 2022 13:37:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662471439; bh=F0eM71e91+JZcsQVtYIET15R7F56/3gtOSliUrL1LwE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zu2n8syaN3hyzhbASZhBWmFS6EupNRLydhAUqISBmxGQQP5djCY/XxzZIHGQIsxKA aGPSoP9ZVOZiRlHtbz5oIIIYwzSC13VL0EgRUIc6F4iJsPBYz4/9qxEE+kbRFfY+BE T7RC+QEXT+EAKpXvzPpcjQ+lXN3N6qRC3sXiTXuE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= , Jakub Kicinski , Sasha Levin , zdi-disclosures@trendmicro.com Subject: [PATCH 5.15 026/107] sch_cake: Return __NET_XMIT_STOLEN when consuming enqueued skb Date: Tue, 6 Sep 2022 15:30:07 +0200 Message-Id: <20220906132822.891871800@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220906132821.713989422@linuxfoundation.org> References: <20220906132821.713989422@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: Toke Høiland-Jørgensen [ Upstream commit 90fabae8a2c225c4e4936723c38857887edde5cc ] When the GSO splitting feature of sch_cake is enabled, GSO superpackets will be broken up and the resulting segments enqueued in place of the original skb. In this case, CAKE calls consume_skb() on the original skb, but still returns NET_XMIT_SUCCESS. This can confuse parent qdiscs into assuming the original skb still exists, when it really has been freed. Fix this by adding the __NET_XMIT_STOLEN flag to the return value in this case. Fixes: 0c850344d388 ("sch_cake: Conditionally split GSO segments") Signed-off-by: Toke Høiland-Jørgensen Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-18231 Link: https://lore.kernel.org/r/20220831092103.442868-1-toke@toke.dk Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sched/sch_cake.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index 857aaebd49f43..6944c669731c4 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -1713,6 +1713,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch, } idx--; flow = &b->flows[idx]; + ret = NET_XMIT_SUCCESS; /* ensure shaper state isn't stale */ if (!b->tin_backlog) { @@ -1771,6 +1772,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch, qdisc_tree_reduce_backlog(sch, 1-numsegs, len-slen); consume_skb(skb); + ret |= __NET_XMIT_STOLEN; } else { /* not splitting */ cobalt_set_enqueue_time(skb, now); @@ -1904,7 +1906,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch, } b->drop_overlimit += dropped; } - return NET_XMIT_SUCCESS; + return ret; } static struct sk_buff *cake_dequeue_one(struct Qdisc *sch) -- 2.35.1