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 40C5AC433EF for ; Mon, 13 Dec 2021 10:03:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240962AbhLMKCw (ORCPT ); Mon, 13 Dec 2021 05:02:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239416AbhLMJ5Q (ORCPT ); Mon, 13 Dec 2021 04:57:16 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89298C0698CD; Mon, 13 Dec 2021 01:48:10 -0800 (PST) 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 sin.source.kernel.org (Postfix) with ESMTPS id D3BEDCE0E77; Mon, 13 Dec 2021 09:48:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F360C341C5; Mon, 13 Dec 2021 09:48:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1639388887; bh=odmEsfDm6TOHJpP7tZ6AaJP0+19wi3rkYp8kCQzl87Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r5/Rtmz032H6C3zCHwki3nfA6mVxjr1RHuVjSpVsuCCdhgPgF8XD2fBIP58bx7v0E cGfYoyqyTivaExIVLYpymdQivACKZlFYLe9tBQyaIjfwjkjF5aej6yx66RSO3Nnmrb 8wYpoWkDTVpTebOw10Eft6nZ7dp/rjxcalvC1nSY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot , "Mohit P. Tahiliani" , "Sachin D. Patil" , "V. Saicharan" , Mohit Bhasi , Leslie Monis , Gautam Ramakrishnan , Jakub Kicinski Subject: [PATCH 5.10 042/132] net/sched: fq_pie: prevent dismantle issue Date: Mon, 13 Dec 2021 10:29:43 +0100 Message-Id: <20211213092940.564989416@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211213092939.074326017@linuxfoundation.org> References: <20211213092939.074326017@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet commit 61c2402665f1e10c5742033fce18392e369931d7 upstream. For some reason, fq_pie_destroy() did not copy working code from pie_destroy() and other qdiscs, thus causing elusive bug. Before calling del_timer_sync(&q->adapt_timer), we need to ensure timer will not rearm itself. rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (4416 ticks this GP) idle=60d/1/0x4000000000000000 softirq=10433/10434 fqs=2579 (t=10501 jiffies g=13085 q=3989) NMI backtrace for cpu 0 CPU: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:write_comp_data kernel/kcov.c:221 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x1d/0x80 kernel/kcov.c:273 Code: 54 c8 20 48 89 10 c3 66 0f 1f 44 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 8b 0c 25 40 70 02 00 48 89 ce 4c 8b 54 24 08 4e f7 ff ff 84 c0 74 51 48 8b 81 88 15 00 00 44 8b 81 84 15 00 RSP: 0018:ffffc90000d27b28 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff888064bf1bf0 RCX: ffff888011928000 RDX: ffff888011928000 RSI: ffff888011928000 RDI: 0000000000000003 RBP: ffff888064bf1c28 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff875d8295 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880783dd300 R14: 0000000000000000 R15: 0000000000000000 pie_calculate_probability+0x405/0x7c0 net/sched/sch_pie.c:418 fq_pie_timer+0x170/0x2a0 net/sched/sch_fq_pie.c:383 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 run_ksoftirqd kernel/softirq.c:921 [inline] run_ksoftirqd+0x2d/0x60 kernel/softirq.c:913 smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler") Signed-off-by: Eric Dumazet Reported-by: syzbot Cc: Mohit P. Tahiliani Cc: Sachin D. Patil Cc: V. Saicharan Cc: Mohit Bhasi Cc: Leslie Monis Cc: Gautam Ramakrishnan Link: https://lore.kernel.org/r/20211209084937.3500020-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_fq_pie.c | 1 + 1 file changed, 1 insertion(+) --- a/net/sched/sch_fq_pie.c +++ b/net/sched/sch_fq_pie.c @@ -531,6 +531,7 @@ static void fq_pie_destroy(struct Qdisc struct fq_pie_sched_data *q = qdisc_priv(sch); tcf_block_put(q->block); + q->p_params.tupdate = 0; del_timer_sync(&q->adapt_timer); kvfree(q->flows); }