From patchwork Mon Jan 7 19:47:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= X-Patchwork-Id: 1021558 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=toke.dk Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; secure) header.d=toke.dk header.i=@toke.dk header.b="qRr6iX08"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43YQt74MlSz9rxp for ; Tue, 8 Jan 2019 06:48:15 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728117AbfAGTsO (ORCPT ); Mon, 7 Jan 2019 14:48:14 -0500 Received: from mail.toke.dk ([52.28.52.200]:41665 "EHLO mail.toke.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726654AbfAGTsO (ORCPT ); Mon, 7 Jan 2019 14:48:14 -0500 From: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=toke.dk; s=20161023; t=1546890490; bh=Iw5yow27A058YikjHbxO7bw1kgWaarEpoRETKJcy4zA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qRr6iX08gnEr7ZZ18NULozVWTGseD69ME3+lEa3Paidwwi26nvn3xzVcoLRMqyNVU zki6eTx2rGabZPzcFCNzLJxyeCCr/Jo2A1V5jiXLl/uudF1dBUBLZ5jV9gWl2ex6w7 F+Z/J4B4s0TKhVCId+XD2u3+YpvTchLhVO2CGU8YPyIrD061ygm6Y0QyvZHA/fKysw vi1UqMyqsf3XVhRAqethaWzmJxlTU9rkIcWuYvKiT5D6JJ/2z2Vw6kE4sPrHNw3F6G ReWvjI5IkU3xOrLtzVdd69h+C8ziiG0aCh810obqygH7xOPvUsEDj2aJ7pjxguVKWN RiwKtuBEhRpog== To: netdev@vger.kernel.org Cc: cake@lists.bufferbloat.net, =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= Subject: [PATCH 1/4] sched: Avoid dereferencing skb pointer after child enqueue Date: Mon, 7 Jan 2019 20:47:30 +0100 Message-Id: <20190107194733.31138-2-toke@toke.dk> In-Reply-To: <20190107194733.31138-1-toke@toke.dk> References: <20190107194733.31138-1-toke@toke.dk> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Toke Høiland-Jørgensen Parent qdiscs may dereference the pointer to the enqueued skb after enqueue. However, both CAKE and TBF call consume_skb() on the original skb when splitting GSO packets, leading to a potential use-after-free in the parent. Fix this by avoiding dereferencing the skb pointer after enqueueing to the child. Signed-off-by: Toke Høiland-Jørgensen --- net/sched/sch_cbs.c | 3 ++- net/sched/sch_drr.c | 3 ++- net/sched/sch_dsmark.c | 3 ++- net/sched/sch_hfsc.c | 5 ++--- net/sched/sch_htb.c | 3 ++- net/sched/sch_prio.c | 3 ++- net/sched/sch_qfq.c | 16 +++++++++------- net/sched/sch_tbf.c | 3 ++- 8 files changed, 23 insertions(+), 16 deletions(-) diff --git a/net/sched/sch_cbs.c b/net/sched/sch_cbs.c index e689e11b6d0f..c6a502933fe7 100644 --- a/net/sched/sch_cbs.c +++ b/net/sched/sch_cbs.c @@ -88,13 +88,14 @@ static int cbs_child_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct Qdisc *child, struct sk_buff **to_free) { + unsigned int len = qdisc_pkt_len(skb); int err; err = child->ops->enqueue(skb, child, to_free); if (err != NET_XMIT_SUCCESS) return err; - qdisc_qstats_backlog_inc(sch, skb); + sch->qstats.backlog += len; sch->q.qlen++; return NET_XMIT_SUCCESS; diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c index cdebaed0f8cf..feaf47178653 100644 --- a/net/sched/sch_drr.c +++ b/net/sched/sch_drr.c @@ -350,6 +350,7 @@ static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch, static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { + unsigned int len = qdisc_pkt_len(skb); struct drr_sched *q = qdisc_priv(sch); struct drr_class *cl; int err = 0; @@ -376,7 +377,7 @@ static int drr_enqueue(struct sk_buff *skb, struct Qdisc *sch, cl->deficit = cl->quantum; } - qdisc_qstats_backlog_inc(sch, skb); + sch->qstats.backlog += len; sch->q.qlen++; return err; } diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c index f6f480784bc6..42471464ded3 100644 --- a/net/sched/sch_dsmark.c +++ b/net/sched/sch_dsmark.c @@ -199,6 +199,7 @@ static struct tcf_block *dsmark_tcf_block(struct Qdisc *sch, unsigned long cl, static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { + unsigned int len = qdisc_pkt_len(skb); struct dsmark_qdisc_data *p = qdisc_priv(sch); int err; @@ -271,7 +272,7 @@ static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch, return err; } - qdisc_qstats_backlog_inc(sch, skb); + sch->qstats.backlog += len; sch->q.qlen++; return NET_XMIT_SUCCESS; diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index b18ec1f6de60..6bb8f73a8473 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -1539,6 +1539,7 @@ hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb) static int hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { + unsigned int len = qdisc_pkt_len(skb); struct hfsc_class *cl; int uninitialized_var(err); @@ -1560,8 +1561,6 @@ hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) } if (cl->qdisc->q.qlen == 1) { - unsigned int len = qdisc_pkt_len(skb); - if (cl->cl_flags & HFSC_RSC) init_ed(cl, len); if (cl->cl_flags & HFSC_FSC) @@ -1576,7 +1575,7 @@ hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) } - qdisc_qstats_backlog_inc(sch, skb); + sch->qstats.backlog += len; sch->q.qlen++; return NET_XMIT_SUCCESS; diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c index 58b449490757..30f9da7e1076 100644 --- a/net/sched/sch_htb.c +++ b/net/sched/sch_htb.c @@ -581,6 +581,7 @@ static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { int uninitialized_var(ret); + unsigned int len = qdisc_pkt_len(skb); struct htb_sched *q = qdisc_priv(sch); struct htb_class *cl = htb_classify(skb, sch, &ret); @@ -610,7 +611,7 @@ static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch, htb_activate(q, cl); } - qdisc_qstats_backlog_inc(sch, skb); + sch->qstats.backlog += len; sch->q.qlen++; return NET_XMIT_SUCCESS; } diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c index cdf68706e40f..847141cd900f 100644 --- a/net/sched/sch_prio.c +++ b/net/sched/sch_prio.c @@ -72,6 +72,7 @@ prio_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr) static int prio_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { + unsigned int len = qdisc_pkt_len(skb); struct Qdisc *qdisc; int ret; @@ -88,7 +89,7 @@ prio_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) ret = qdisc_enqueue(skb, qdisc, to_free); if (ret == NET_XMIT_SUCCESS) { - qdisc_qstats_backlog_inc(sch, skb); + sch->qstats.backlog += len; sch->q.qlen++; return NET_XMIT_SUCCESS; } diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c index dc37c4ead439..8d5e55d5bed2 100644 --- a/net/sched/sch_qfq.c +++ b/net/sched/sch_qfq.c @@ -1210,6 +1210,7 @@ static struct qfq_aggregate *qfq_choose_next_agg(struct qfq_sched *q) static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { + unsigned int len = qdisc_pkt_len(skb), gso_segs; struct qfq_sched *q = qdisc_priv(sch); struct qfq_class *cl; struct qfq_aggregate *agg; @@ -1224,17 +1225,17 @@ static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, } pr_debug("qfq_enqueue: cl = %x\n", cl->common.classid); - if (unlikely(cl->agg->lmax < qdisc_pkt_len(skb))) { + if (unlikely(cl->agg->lmax < len)) { pr_debug("qfq: increasing maxpkt from %u to %u for class %u", - cl->agg->lmax, qdisc_pkt_len(skb), cl->common.classid); - err = qfq_change_agg(sch, cl, cl->agg->class_weight, - qdisc_pkt_len(skb)); + cl->agg->lmax, len, cl->common.classid); + err = qfq_change_agg(sch, cl, cl->agg->class_weight, len); if (err) { cl->qstats.drops++; return qdisc_drop(skb, sch, to_free); } } + gso_segs = skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1; err = qdisc_enqueue(skb, cl->qdisc, to_free); if (unlikely(err != NET_XMIT_SUCCESS)) { pr_debug("qfq_enqueue: enqueue failed %d\n", err); @@ -1245,8 +1246,9 @@ static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, return err; } - bstats_update(&cl->bstats, skb); - qdisc_qstats_backlog_inc(sch, skb); + cl->bstats.bytes += len; + cl->bstats.packets += gso_segs; + sch->qstats.backlog += len; ++sch->q.qlen; agg = cl->agg; @@ -1254,7 +1256,7 @@ static int qfq_enqueue(struct sk_buff *skb, struct Qdisc *sch, if (cl->qdisc->q.qlen != 1) { if (unlikely(skb == cl->qdisc->ops->peek(cl->qdisc)) && list_first_entry(&agg->active, struct qfq_class, alist) - == cl && cl->deficit < qdisc_pkt_len(skb)) + == cl && cl->deficit < len) list_move_tail(&cl->alist, &agg->active); return err; diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c index 942dcca09cf2..7f272a9070c5 100644 --- a/net/sched/sch_tbf.c +++ b/net/sched/sch_tbf.c @@ -185,6 +185,7 @@ static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free) { struct tbf_sched_data *q = qdisc_priv(sch); + unsigned int len = qdisc_pkt_len(skb); int ret; if (qdisc_pkt_len(skb) > q->max_size) { @@ -200,7 +201,7 @@ static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch, return ret; } - qdisc_qstats_backlog_inc(sch, skb); + sch->qstats.backlog += len; sch->q.qlen++; return NET_XMIT_SUCCESS; }