From 68aab823c223646fab311f8a6581994facee66a0 Mon Sep 17 00:00:00 2001 From: Wen Yang Date: Thu, 2 Jan 2020 17:21:43 +0800 Subject: sch_cake: avoid possible divide by zero in cake_enqueue() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The variables 'window_interval' is u64 and do_div() truncates it to 32 bits, which means it can test non-zero and be truncated to zero for division. The unit of window_interval is nanoseconds, so its lower 32-bit is relatively easy to exceed. Fix this issue by using div64_u64() instead. Fixes: 7298de9cd725 ("sch_cake: Add ingress mode") Signed-off-by: Wen Yang Cc: Kevin Darbyshire-Bryant Cc: Toke Høiland-Jørgensen Cc: David S. Miller Cc: Cong Wang Cc: cake@lists.bufferbloat.net Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Acked-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller --- net/sched/sch_cake.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/sched') diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index e0f40400f679..2277369feae5 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -1769,7 +1769,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch, q->avg_window_begin)); u64 b = q->avg_window_bytes * (u64)NSEC_PER_SEC; - do_div(b, window_interval); + b = div64_u64(b, window_interval); q->avg_peak_bandwidth = cake_ewma(q->avg_peak_bandwidth, b, b > q->avg_peak_bandwidth ? 2 : 8); -- cgit v1.2.3 From d9e15a2733067c9328fb56d98fe8e574fa19ec31 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 6 Jan 2020 06:10:39 -0800 Subject: pkt_sched: fq: do not accept silly TCA_FQ_QUANTUM As diagnosed by Florian : If TCA_FQ_QUANTUM is set to 0x80000000, fq_deueue() can loop forever in : if (f->credit <= 0) { f->credit += q->quantum; goto begin; } ... because f->credit is either 0 or -2147483648. Let's limit TCA_FQ_QUANTUM to no more than 1 << 20 : This max value should limit risks of breaking user setups while fixing this bug. Fixes: afe4fd062416 ("pkt_sched: fq: Fair Queue packet scheduler") Signed-off-by: Eric Dumazet Diagnosed-by: Florian Westphal Reported-by: syzbot+dc9071cc5a85950bdfce@syzkaller.appspotmail.com Signed-off-by: David S. Miller --- net/sched/sch_fq.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'net/sched') diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c index ff4c5e9d0d77..a5a295477ecc 100644 --- a/net/sched/sch_fq.c +++ b/net/sched/sch_fq.c @@ -786,10 +786,12 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt, if (tb[TCA_FQ_QUANTUM]) { u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]); - if (quantum > 0) + if (quantum > 0 && quantum <= (1 << 20)) { q->quantum = quantum; - else + } else { + NL_SET_ERR_MSG_MOD(extack, "invalid quantum"); err = -EINVAL; + } } if (tb[TCA_FQ_INITIAL_QUANTUM]) -- cgit v1.2.3 From 240ce7f6428ff5188b9eedc066e1e4d645b8635f Mon Sep 17 00:00:00 2001 From: Petr Machata Date: Mon, 6 Jan 2020 18:01:56 +0000 Subject: net: sch_prio: When ungrafting, replace with FIFO When a child Qdisc is removed from one of the PRIO Qdisc's bands, it is replaced unconditionally by a NOOP qdisc. As a result, any traffic hitting that band gets dropped. That is incorrect--no Qdisc was explicitly added when PRIO was created, and after removal, none should have to be added either. Fix PRIO by first attempting to create a default Qdisc and only falling back to noop when that fails. This pattern of attempting to create an invisible FIFO, using NOOP only as a fallback, is also seen in other Qdiscs. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Petr Machata Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- net/sched/sch_prio.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'net/sched') diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c index 18b884cfdfe8..647941702f9f 100644 --- a/net/sched/sch_prio.c +++ b/net/sched/sch_prio.c @@ -292,8 +292,14 @@ static int prio_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, struct tc_prio_qopt_offload graft_offload; unsigned long band = arg - 1; - if (new == NULL) - new = &noop_qdisc; + if (!new) { + new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, + TC_H_MAKE(sch->handle, arg), extack); + if (!new) + new = &noop_qdisc; + else + qdisc_hash_add(new, true); + } *old = qdisc_replace(sch, new, &q->queues[band]); -- cgit v1.2.3