Re: WARNING in dev_watchdog

From: Dison River
Date: Mon Jun 12 2017 - 04:13:51 EST


Sorry,this WARNING is not reproducible.And I don't have PoC for this bug.

2017-06-12 14:42 GMT+08:00 Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>:
> On Mon, Jun 12, 2017 at 02:37:22PM +0800, Dison River wrote:
>> Hi:
>> I've got the following error report while fuzzing the kernel with
>> syzkaller on linux-4.11.0-rc3.
>>
>> log:
>> WARNING: CPU: 2 PID: 0 at net/sched/sch_generic.c:316
>> dev_watchdog+0x648/0x770 net/sched/sch_generic.c:315
>> NETDEV WATCHDOG: eth0 (e1000): transmit queue 0 timed out
>> Kernel panic - not syncing: panic_on_warn set ...
>>
>> CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.11.0-rc3 #2
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
>> Ubuntu-1.8.2-1ubuntu1 04/01/2014
>> Call Trace:
>> <IRQ>
>> __dump_stack lib/dump_stack.c:16 [inline]
>> dump_stack+0x95/0xe8 lib/dump_stack.c:52
>> panic+0x1ae/0x386 kernel/panic.c:180
>> __warn+0x1c4/0x1e0 kernel/panic.c:541
>> warn_slowpath_fmt+0xac/0xd0 kernel/panic.c:564
>> dev_watchdog+0x648/0x770 net/sched/sch_generic.c:315
>> call_timer_fn+0x15b/0x5e0 kernel/time/timer.c:1268
>> expire_timers kernel/time/timer.c:1307 [inline]
>> __run_timers kernel/time/timer.c:1601 [inline]
>> run_timer_softirq+0x5c7/0x1140 kernel/time/timer.c:1614
>> __do_softirq+0x217/0x8b7 kernel/softirq.c:284
>> invoke_softirq kernel/softirq.c:364 [inline]
>> irq_exit+0x198/0x1d0 kernel/softirq.c:405
>> exiting_irq arch/x86/include/asm/apic.h:657 [inline]
>> smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:962
>> apic_timer_interrupt+0x90/0xa0 arch/x86/entry/entry_64.S:707
>> RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:53 [inline]
>> RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:95 [inline]
>> RIP: 0010:default_idle+0x1f/0x2d0 arch/x86/kernel/process.c:275
>> RSP: 0018:ffff88006dee7e78 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10
>> RAX: 0000000000000007 RBX: ffff88006de9db40 RCX: 0000000000000000
>> RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88006de9e314
>> RBP: ffff88006dee7e98 R08: 0000000000000040 R09: 0000000000000000
>> R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff83efc9b8
>> R13: ffff88006de9db40 R14: 0000000000000002 R15: ffff88006de9db40
>> </IRQ>
>> arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:266
>> default_idle_call+0x36/0x50 kernel/sched/idle.c:97
>> cpuidle_idle_call kernel/sched/idle.c:155 [inline]
>> do_idle+0x20b/0x2d0 kernel/sched/idle.c:244
>> cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:346
>> start_secondary+0x245/0x2d0 arch/x86/kernel/smpboot.c:275
>> start_cpu+0x14/0x14 arch/x86/kernel/head_64.S:306
>> Dumping ftrace buffer:
>> (ftrace buffer empty)
>> Kernel Offset: disabled
>> Rebooting in 86400 seconds..
>>
>>
>> report :
>>
>>
>> syzkaller login: [ 37.041894] ------------[ cut here ]------------
>> [ 37.042430] WARNING: CPU: 2 PID: 0 at net/sched/sch_generic.c:316
>> dev_watchdog+0x648/0x770
>> [ 37.042978] NETDEV WATCHDOG: eth0 (e1000): transmit queue 0 timed out
>> [ 37.043405] Kernel panic - not syncing: panic_on_warn set ...
>> [ 37.043405]
>> [ 37.043888] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.11.0-rc3 #2
>> [ 37.044297] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
>> BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
>> [ 37.044909] Call Trace:
>> [ 37.045080] <IRQ>
>> [ 37.045226] dump_stack+0x95/0xe8
>> [ 37.045453] ? dev_watchdog+0x648/0x770
>> [ 37.045712] panic+0x1ae/0x386
>> [ 37.045924] ? percpu_up_read_preempt_enable.constprop.53+0xae/0xae
>> [ 37.046342] ? dev_watchdog+0x648/0x770
>> [ 37.046605] ? vprintk_default+0x28/0x30
>> [ 37.046873] ? dev_watchdog+0x648/0x770
>> [ 37.047114] __warn+0x1c4/0x1e0
>> [ 37.047820] warn_slowpath_fmt+0xac/0xd0
>> [ 37.048467] ? __warn+0x1e0/0x1e0
>> [ 37.048698] ? dev_watchdog+0x125/0x770
>> [ 37.048963] dev_watchdog+0x648/0x770
>> [ 37.049218] call_timer_fn+0x15b/0x5e0
>> [ 37.049475] ? call_timer_fn+0xcc/0x5e0
>> [ 37.049739] ? qdisc_rcu_free+0x110/0x110
>> [ 37.050014] ? process_timeout+0x20/0x20
>> [ 37.050285] ? trace_hardirqs_on_caller+0x19e/0x580
>> [ 37.053699] ? qdisc_rcu_free+0x110/0x110
>> [ 37.054931] ? qdisc_rcu_free+0x110/0x110
>> [ 37.055296] run_timer_softirq+0x5c7/0x1140
>> [ 37.055949] ? msleep_interruptible+0x170/0x170
>> [ 37.056671] ? lapic_timer_shutdown+0x3d/0x50
>> [ 37.057268] ? clockevents_switch_state+0xe3/0x320
>> [ 37.057837] __do_softirq+0x217/0x8b7
>> [ 37.058097] irq_exit+0x198/0x1d0
>> [ 37.058326] smp_apic_timer_interrupt+0x76/0xa0
>> [ 37.058634] apic_timer_interrupt+0x90/0xa0
>> [ 37.058921] RIP: 0010:default_idle+0x1f/0x2d0
>> [ 37.059217] RSP: 0018:ffff88006dee7e78 EFLAGS: 00000246 ORIG_RAX:
>> ffffffffffffff10
>> [ 37.059702] RAX: 0000000000000007 RBX: ffff88006de9db40 RCX: 0000000000000000
>> [ 37.060179] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88006de9e314
>> [ 37.065968] RBP: ffff88006dee7e98 R08: 0000000000000040 R09: 0000000000000000
>> [ 37.066451] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff83efc9b8
>> [ 37.073921] R13: ffff88006de9db40 R14: 0000000000000002 R15: ffff88006de9db40
>> [ 37.074405] </IRQ>
>> [ 37.074767] ? default_idle+0x1d/0x2d0
>> [ 37.075026] arch_cpu_idle+0xa/0x10
>> [ 37.075266] default_idle_call+0x36/0x50
>> [ 37.075534] do_idle+0x20b/0x2d0
>> [ 37.075815] cpu_startup_entry+0x18/0x20
>> [ 37.076084] start_secondary+0x245/0x2d0
>> [ 37.076352] start_cpu+0x14/0x14
>> [ 37.077025] Dumping ftrace buffer:
>> [ 37.077308] (ftrace buffer empty)
>> [ 37.077555] Kernel Offset: disabled
>> [ 37.078786] Rebooting in 86400 seconds..
>
> Any hints as to exactly what you were doing at the time, and a
> reproducer so we could try to test this?
>
> thanks,
>
> greg k-h