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MIME-Version: 1.0
Date:   Mon, 19 Apr 2021 00:19:15 -0700
Message-ID: <000000000000a9b79905c04e25a0@google.com>
Subject: [syzbot] INFO: rcu detected stall in tx
From:   syzbot <syzbot+e2eae5639e7203360018@syzkaller.appspotmail.com>
To:     bp@alien8.de, dwmw@amazon.co.uk, hpa@zytor.com,
        linux-kernel@vger.kernel.org, luto@kernel.org, mingo@redhat.com,
        syzkaller-bugs@googlegroups.com, tglx@linutronix.de, x86@kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hello,

syzbot found the following issue on:

HEAD commit:    50987bec Merge tag 'trace-v5.12-rc7' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1065c5fcd00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=398c4d0fe6f66e68
dashboard link: https://syzkaller.appspot.com/bug?extid=e2eae5639e7203360018

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e2eae5639e7203360018@syzkaller.appspotmail.com

usbtmc 5-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 5-1:0.0: unknown status received: -71
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (8580 ticks this GP) idle=72e/1/0x4000000000000000 softirq=20679/20679 fqs=0 
	(t=10500 jiffies g=27129 q=416)
rcu: rcu_preempt kthread starved for 10500 jiffies! g27129 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:29168 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4322 [inline]
 __schedule+0x911/0x21b0 kernel/sched/core.c:5073
 schedule+0xcf/0x270 kernel/sched/core.c:5152
 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1892
 rcu_gp_fqs_loop kernel/rcu/tree.c:2005 [inline]
 rcu_gp_kthread+0xd07/0x2250 kernel/rcu/tree.c:2178
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3232 Comm: aoe_tx0 Not tainted 5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:native_apic_mem_write+0x8/0x10 arch/x86/include/asm/apic.h:110
Code: c7 40 d9 36 8f e8 c8 11 86 00 eb b0 66 0f 1f 44 00 00 be 01 00 00 00 e9 36 c7 2c 00 cc cc cc cc cc cc 89 ff 89 b7 00 c0 5f ff <c3> 0f 1f 80 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 53 89 fb 48
RSP: 0018:ffffc90000007ea8 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffffffff8b0a78c0 RCX: 0000000000000020
RDX: 1ffffffff1614f1a RSI: 000000000001c285 RDI: 0000000000000380
RBP: ffff8880b9c1f2c0 R08: 000000000000003f R09: 0000000000000000
R10: ffffffff8166ecf7 R11: 0000000000000000 R12: 000000000001c285
R13: 0000000000000020 R14: ffff8880b9c26340 R15: 0000006120792e26
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb9e6cdb380 CR3: 0000000018792000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 apic_write arch/x86/include/asm/apic.h:393 [inline]
 lapic_next_event+0x4d/0x80 arch/x86/kernel/apic/apic.c:472
 clockevents_program_event+0x254/0x370 kernel/time/clockevents.c:334
 tick_program_event+0xac/0x140 kernel/time/tick-oneshot.c:44
 hrtimer_interrupt+0x414/0xa00 kernel/time/hrtimer.c:1676
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:197
Code: f0 4d 89 03 e9 f2 fc ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 40 00 <65> 8b 05 39 fe 8d 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b
RSP: 0018:ffffc900030cf6f8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88801aff1c40 RSI: ffffffff815c2e4f RDI: 0000000000000003
RBP: ffffc900030cf738 R08: 0000000000000000 R09: ffffffff8fa9a96f
R10: ffffffff815c2e45 R11: 0000000000000000 R12: 000000000000002d
R13: ffff8880113db880 R14: 0000000000000000 R15: 0000000000000200
 console_trylock_spinning kernel/printk/printk.c:1818 [inline]
 vprintk_emit+0x3a5/0x560 kernel/printk/printk.c:2097
 dev_vprintk_emit+0x36e/0x3b2 drivers/base/core.c:4434
 dev_printk_emit+0xba/0xf1 drivers/base/core.c:4445
 __netdev_printk+0x1c6/0x27a net/core/dev.c:11292
 netdev_warn+0xd7/0x109 net/core/dev.c:11345
 ieee802154_subif_start_xmit.cold+0x17/0x27 net/mac802154/tx.c:125
 __netdev_start_xmit include/linux/netdevice.h:4825 [inline]
 netdev_start_xmit include/linux/netdevice.h:4839 [inline]
 xmit_one net/core/dev.c:3605 [inline]
 dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3621
 sch_direct_xmit+0x2e1/0xbd0 net/sched/sch_generic.c:313
 qdisc_restart net/sched/sch_generic.c:376 [inline]
 __qdisc_run+0x4ba/0x15f0 net/sched/sch_generic.c:384
 qdisc_run include/net/pkt_sched.h:136 [inline]
 qdisc_run include/net/pkt_sched.h:128 [inline]
 __dev_xmit_skb net/core/dev.c:3807 [inline]
 __dev_queue_xmit+0x14b9/0x2e00 net/core/dev.c:4162
 tx+0x68/0xb0 drivers/block/aoe/aoenet.c:63
 kthread+0x1e7/0x3a0 drivers/block/aoe/aoecmd.c:1230
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
NMI backtrace for cpu 1
CPU: 1 PID: 37 Comm: kworker/1:1 Not tainted 5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events nsim_dev_trap_report_work
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 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+0x222/0x2a7 kernel/rcu/tree_stall.h:341
 print_cpu_stall kernel/rcu/tree_stall.h:622 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:697 [inline]
 rcu_pending kernel/rcu/tree.c:3830 [inline]
 rcu_sched_clock_irq.cold+0x4f7/0x11dd kernel/rcu/tree.c:2650
 update_process_times+0x16d/0x200 kernel/time/timer.c:1796
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1369
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x1c0/0xe40 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:632
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70 kernel/locking/spinlock.c:191
Code: 74 24 10 e8 ba 19 54 f8 48 89 ef e8 f2 cf 54 f8 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 <e8> d3 9d 48 f8 65 8b 05 7c 68 fc 76 85 c0 74 0a 5b 5d c3 e8 40 59
RSP: 0018:ffffc90000dc0b28 EFLAGS: 00000206
RAX: 0000000000000002 RBX: 0000000000000200 RCX: 1ffffffff1f5f34a
RDX: 0000000000000000 RSI: 0000000000000103 RDI: 0000000000000001
RBP: ffff888144fa8000 R08: 0000000000000001 R09: ffffffff8fa9a99f
R10: 0000000000000001 R11: ffffc90013880000 R12: ffff888145047440
R13: ffff88801ee8e500 R14: dffffc0000000000 R15: ffff888011f69c00
 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline]
 dummy_timer+0x12f1/0x32a0 drivers/usb/gadget/udc/dummy_hcd.c:1985
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1431
 expire_timers kernel/time/timer.c:1476 [inline]
 __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1745
 __run_timers kernel/time/timer.c:1726 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1758
 __do_softirq+0x29b/0x9f6 kernel/softirq.c:345
 do_softirq.part.0+0xd9/0x130 kernel/softirq.c:248
 </IRQ>
 do_softirq kernel/softirq.c:240 [inline]
 __local_bh_enable_ip+0x102/0x120 kernel/softirq.c:198
 spin_unlock_bh include/linux/spinlock.h:399 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:585 [inline]
 nsim_dev_trap_report_work+0x867/0xbd0 drivers/net/netdevsim/dev.c:611
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 5-1:0.0: unknown status received: -71
usbtmc 5-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 5-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 5-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 2-1:0.0: unknown status received: -71
usbtmc 4-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: unknown status received: -71
usbtmc 3-1:0.0: usb_submit_urb failed: -19
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: unknown status received: -71
usbtmc 6-1:0.0: usb_submit_urb failed: -19


---
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