From patchwork Wed Jan 9 16:09:42 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: 1022501 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=fail (p=none dis=none) header.from=redhat.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43ZYy74tXGz9sD9 for ; Thu, 10 Jan 2019 03:10:39 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732604AbfAIQKi (ORCPT ); Wed, 9 Jan 2019 11:10:38 -0500 Received: from mail-wm1-f65.google.com ([209.85.128.65]:50985 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731928AbfAIQKi (ORCPT ); Wed, 9 Jan 2019 11:10:38 -0500 Received: by mail-wm1-f65.google.com with SMTP id n190so8247286wmd.0 for ; Wed, 09 Jan 2019 08:10:35 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=GNMx/r/m5SCcKruEHHtrOsaV9nV7U3uk4YlrNpxDL+A=; b=FePCsLvscth64d7/62MENNyguuDF7qQCVKxCXl2bH2eKbdRsbGt9OmMFR0hW3iNavL vaXDPrv8xvJLWitGAQDMiEcFyeia+QOCi/lyqlIsm/N3P8eW8W6mz6wzSBoAxxTHGt/h 5csMVwRUt9aQZU3pjKEZNc7OcaxeTy+Y+ycTc8LvATKly+Rr0YcXv2HVzb+HF9kveAeh oyXC/IMsjpCGG92HeH4KbFSJNxY91i9n0U82HjdDqWodYxlx4I5XOgl3f8B0Z4CD+NJI 0gcAr7Z2fZK7ZR/1wSQrua15q33yOdRqIdu5rB7UYxavwiWvPJFv9FfAVCpZPoV47xME QCpw== X-Gm-Message-State: AJcUukdVe9yF7GxQwCiioTKWo9YHWvJiURjjk9gpUt76cAHjBnlOD36m cFg2FGBvw0krSnm3YptGyJvZqId56+s= X-Google-Smtp-Source: ALg8bN488V4NOeB293TH+Nfo6kICY8LyBhal8Er4qmsD0J75W8Vy3TR2yxtHhFG2Tycb356LZbs09w== X-Received: by 2002:a1c:e715:: with SMTP id e21mr6226674wmh.101.1547050234915; Wed, 09 Jan 2019 08:10:34 -0800 (PST) Received: from tohojo-x1-rh.localdomain ([2a00:7660:6da:1:2262:af2:1f58:2146]) by smtp.gmail.com with ESMTPSA id t4sm62370831wrm.6.2019.01.09.08.10.34 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 09 Jan 2019 08:10:34 -0800 (PST) Received: by tohojo-x1-rh.localdomain (Postfix, from userid 1000) id D456A1833C1; Wed, 9 Jan 2019 17:10:33 +0100 (CET) From: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= To: netdev@vger.kernel.org Cc: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= Subject: [PATCH v2 1/3] sched: Avoid dereferencing skb pointer after child enqueue Date: Wed, 9 Jan 2019 17:09:42 +0100 Message-Id: <20190109160943.18051-2-toke@redhat.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190109160943.18051-1-toke@redhat.com> References: <20190109160943.18051-1-toke@redhat.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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; }