From: Eric Dumazet edumazet@google.com
[ Upstream commit cd2b8113c2e8b9f5a88a942e1eaca61eba401b85 ]
We got multiple syzbot reports, all duplicates of the following [1]
syzbot managed to install fq_pie with a zero TCA_FQ_PIE_QUANTUM, thus triggering infinite loops.
Use limits similar to sch_fq, with commits 3725a269815b ("pkt_sched: fq: avoid hang when quantum 0") and d9e15a273306 ("pkt_sched: fq: do not accept silly TCA_FQ_QUANTUM")
[1] watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [swapper/0:0] Modules linked in: irq event stamp: 172817 hardirqs last enabled at (172816): [<ffff80001242fde4>] __el1_irq arch/arm64/kernel/entry-common.c:476 [inline] hardirqs last enabled at (172816): [<ffff80001242fde4>] el1_interrupt+0x58/0x68 arch/arm64/kernel/entry-common.c:486 hardirqs last disabled at (172817): [<ffff80001242fdb0>] __el1_irq arch/arm64/kernel/entry-common.c:468 [inline] hardirqs last disabled at (172817): [<ffff80001242fdb0>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:486 softirqs last enabled at (167634): [<ffff800008020c1c>] softirq_handle_end kernel/softirq.c:414 [inline] softirqs last enabled at (167634): [<ffff800008020c1c>] __do_softirq+0xac0/0xd54 kernel/softirq.c:600 softirqs last disabled at (167701): [<ffff80000802a660>] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0-rc3-syzkaller-geb0f1697d729 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : fq_pie_qdisc_dequeue+0x10c/0x8ac net/sched/sch_fq_pie.c:246 lr : fq_pie_qdisc_dequeue+0xe4/0x8ac net/sched/sch_fq_pie.c:240 sp : ffff800008007210 x29: ffff800008007280 x28: ffff0000c86f7890 x27: ffff0000cb20c2e8 x26: ffff0000cb20c2f0 x25: dfff800000000000 x24: ffff0000cb20c2e0 x23: ffff0000c86f7880 x22: 0000000000000040 x21: 1fffe000190def10 x20: ffff0000cb20c2e0 x19: ffff0000cb20c2e0 x18: ffff800008006e60 x17: 0000000000000000 x16: ffff80000850af6c x15: 0000000000000302 x14: 0000000000000100 x13: 0000000000000000 x12: 0000000000000001 x11: 0000000000000302 x10: 0000000000000100 x9 : 0000000000000000 x8 : 0000000000000000 x7 : ffff80000841c468 x6 : 0000000000000000 x5 : 0000000000000001 x4 : 0000000000000001 x3 : 0000000000000000 x2 : ffff0000cb20c2e0 x1 : ffff0000cb20c2e0 x0 : 0000000000000001 Call trace: fq_pie_qdisc_dequeue+0x10c/0x8ac net/sched/sch_fq_pie.c:246 dequeue_skb net/sched/sch_generic.c:292 [inline] qdisc_restart net/sched/sch_generic.c:397 [inline] __qdisc_run+0x1fc/0x231c net/sched/sch_generic.c:415 __dev_xmit_skb net/core/dev.c:3868 [inline] __dev_queue_xmit+0xc80/0x3318 net/core/dev.c:4210 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_connected_output+0x2f8/0x38c net/core/neighbour.c:1581 neigh_output include/net/neighbour.h:544 [inline] ip6_finish_output2+0xd60/0x1a1c net/ipv6/ip6_output.c:134 __ip6_finish_output net/ipv6/ip6_output.c:195 [inline] ip6_finish_output+0x538/0x8c8 net/ipv6/ip6_output.c:206 NF_HOOK_COND include/linux/netfilter.h:292 [inline] ip6_output+0x270/0x594 net/ipv6/ip6_output.c:227 dst_output include/net/dst.h:458 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] ndisc_send_skb+0xc30/0x1790 net/ipv6/ndisc.c:508 ndisc_send_rs+0x47c/0x5d4 net/ipv6/ndisc.c:718 addrconf_rs_timer+0x300/0x58c net/ipv6/addrconf.c:3936 call_timer_fn+0x19c/0x8cc kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x55c/0x734 kernel/time/timer.c:2022 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:2035 __do_softirq+0x2d0/0xd54 kernel/softirq.c:571 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:882 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85 invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0x28c/0x534 kernel/softirq.c:650 irq_exit_rcu+0x14/0x84 kernel/softirq.c:662 __el1_irq arch/arm64/kernel/entry-common.c:472 [inline] el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:486 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491 el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:587 __daif_local_irq_enable arch/arm64/include/asm/irqflags.h:33 [inline] arch_local_irq_enable+0x8/0xc arch/arm64/include/asm/irqflags.h:55 cpuidle_idle_call kernel/sched/idle.c:170 [inline] do_idle+0x1f0/0x4e8 kernel/sched/idle.c:282 cpu_startup_entry+0x24/0x28 kernel/sched/idle.c:379 rest_init+0x2dc/0x2f4 init/main.c:735 start_kernel+0x0/0x55c init/main.c:834 start_kernel+0x3f0/0x55c init/main.c:1088 __primary_switched+0xb8/0xc0 arch/arm64/kernel/head.S:523
Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler") Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: Eric Dumazet edumazet@google.com Reviewed-by: Jamal Hadi Salim jhs@mojatatu.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/sched/sch_fq_pie.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c index cf04f70e96bf1..4f6b5b6fba3ed 100644 --- a/net/sched/sch_fq_pie.c +++ b/net/sched/sch_fq_pie.c @@ -201,6 +201,11 @@ static int fq_pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, return NET_XMIT_CN; }
+static struct netlink_range_validation fq_pie_q_range = { + .min = 1, + .max = 1 << 20, +}; + static const struct nla_policy fq_pie_policy[TCA_FQ_PIE_MAX + 1] = { [TCA_FQ_PIE_LIMIT] = {.type = NLA_U32}, [TCA_FQ_PIE_FLOWS] = {.type = NLA_U32}, @@ -208,7 +213,8 @@ static const struct nla_policy fq_pie_policy[TCA_FQ_PIE_MAX + 1] = { [TCA_FQ_PIE_TUPDATE] = {.type = NLA_U32}, [TCA_FQ_PIE_ALPHA] = {.type = NLA_U32}, [TCA_FQ_PIE_BETA] = {.type = NLA_U32}, - [TCA_FQ_PIE_QUANTUM] = {.type = NLA_U32}, + [TCA_FQ_PIE_QUANTUM] = + NLA_POLICY_FULL_RANGE(NLA_U32, &fq_pie_q_range), [TCA_FQ_PIE_MEMORY_LIMIT] = {.type = NLA_U32}, [TCA_FQ_PIE_ECN_PROB] = {.type = NLA_U32}, [TCA_FQ_PIE_ECN] = {.type = NLA_U32},