bridge0: port 1(bridge_slave_0) entered forwarding state
bridge0: port 2(bridge_slave_1) entered forwarding state
bridge0: port 1(bridge_slave_0) entered forwarding state
bridge0: port 2(bridge_slave_1) entered forwarding state
INFO: task syz-executor.5:5346 blocked for more than 140 seconds.
      Not tainted 4.1.0 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D ffff8800b168bbb8 12304  5346      1 0x00000004
 ffff8800b168bbb8 00000000b168bbb8 ffff8800b876ec90 ffff880000000000
 ffff8800b168c000 ffff8800b15d7660 ffff8800b168bd38 ffff8800b876ec90
 0000000000000286 ffff8800b168bbd8 ffffffff826451a2 ffff8800b15d7658
Call Trace:
 [<ffffffff826451a2>] schedule+0x32/0x80 kernel/sched/core.c:2826
 [<ffffffff826455e3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:2858
 [<ffffffff82647f75>] __mutex_lock_common kernel/locking/mutex.c:578 [inline]
 [<ffffffff82647f75>] mutex_lock_nested+0x195/0x610 kernel/locking/mutex.c:617
 [<ffffffff81308ef1>] lookup_slow+0x31/0xc0 fs/namei.c:1508
 [<ffffffff8130b9a8>] walk_component fs/namei.c:1589 [inline]
 [<ffffffff8130b9a8>] link_path_walk+0x688/0x15c0 fs/namei.c:1844
 [<ffffffff8130f3c5>] follow_link fs/namei.c:901 [inline]
 [<ffffffff8130f3c5>] path_mountpoint+0x2f5/0x490 fs/namei.c:2368
 [<ffffffff813116e2>] filename_mountpoint+0x32/0xe0 fs/namei.c:2386
 [<ffffffff813126c1>] user_path_mountpoint_at+0x31/0x40 fs/namei.c:2415
 [<ffffffff81326757>] SYSC_umount fs/namespace.c:1576 [inline]
 [<ffffffff81326757>] SyS_umount+0x67/0x120 fs/namespace.c:1560
 [<ffffffff8264c772>] system_call_fastpath+0x16/0x7a
1 lock held by syz-executor.5/5346:
 #0:  (&type->i_mutex_dir_key#4){+.+.+.}, at: [<ffffffff81308ef1>] lookup_slow+0x31/0xc0 fs/namei.c:1508
sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.1.0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff83214520 ti: ffffffff83200000 task.ti: ffffffff83200000
RIP: 0010:[<ffffffff810caa76>]  [<ffffffff810caa76>] native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:50
RSP: 0018:ffffffff83203e88  EFLAGS: 00000282
RAX: ffffffff83214520 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffffffff83214520
RBP: ffffffff83203e88 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff83200000
R13: ffffffff8341b238 R14: 0000000000000000 R15: ffffffff83200000
FS:  0000000000000000(0000) GS:ffff88012c000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f805a113140 CR3: 000000012af64000 CR4: 00000000001407f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff83203ea8 ffffffff810896e9 0000000000000000 ffffffff83200000
 ffffffff83203eb8 ffffffff8108a62a ffffffff83203f28 ffffffff811bd5e9
 ffffffff83203ed8 ffffffff83204000 ffff88021fffd200 ffffffff83530940
Call Trace:
 [<ffffffff810896e9>] arch_safe_halt arch/x86/include/asm/paravirt.h:111 [inline]
 [<ffffffff810896e9>] default_idle+0x29/0x270 arch/x86/kernel/process.c:341
 [<ffffffff8108a62a>] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:332
 [<ffffffff811bd5e9>] cpuidle_idle_call kernel/sched/idle.c:195 [inline]
 [<ffffffff811bd5e9>] cpu_idle_loop kernel/sched/idle.c:249 [inline]
 [<ffffffff811bd5e9>] cpu_startup_entry+0x2e9/0x660 kernel/sched/idle.c:297
 [<ffffffff82633d34>] rest_init+0x134/0x140 init/main.c:409
 [<ffffffff83450f89>] start_kernel+0x438/0x445 init/main.c:677
 [<ffffffff83450345>] x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:197
 [<ffffffff8345048c>] x86_64_start_kernel+0x145/0x154 arch/x86/kernel/head64.c:186
Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84 
NMI backtrace for cpu 1
CPU: 1 PID: 871 Comm: khungtaskd Not tainted 4.1.0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff880129d288d0 ti: ffff880129cb8000 task.ti: ffff880129cb8000
RIP: 0010:[<ffffffff810ca94a>]  [<ffffffff810ca94a>] native_write_msr_safe+0xa/0x10 arch/x86/include/asm/msr.h:95
RSP: 0018:ffff880129cbbd08  EFLAGS: 00000082
RAX: 0000000000000400 RBX: 0000000000000001 RCX: 0000000000000830
RDX: 0000000000000001 RSI: 0000000000000400 RDI: 0000000000000830
RBP: ffff880129cbbd08 R08: 0000000000000000 R09: 0000000000000003
R10: ffff880129d288d0 R11: 0000000000000001 R12: ffffffff8341ad08
R13: 0000000000080000 R14: 0000000000000001 R15: 000000000000a120
FS:  0000000000000000(0000) GS:ffff88012c100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f805a113140 CR3: 00000000b1f98000 CR4: 00000000001407e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff880129cbbd68 ffffffff810c502f ffff880129cbbd78 0000000000000296
 0000000200000002 0000000000000002 ffff880129cbbd88 0000000000000040
 000000000000d3c0 0000000000000001 ffff8800b876ec90 000000000000008c
Call Trace:
 [<ffffffff810c502f>] paravirt_write_msr arch/x86/include/asm/paravirt.h:133 [inline]
 [<ffffffff810c502f>] native_x2apic_icr_write arch/x86/include/asm/apic.h:168 [inline]
 [<ffffffff810c502f>] __x2apic_send_IPI_dest arch/x86/include/asm/x2apic.h:26 [inline]
 [<ffffffff810c502f>] __x2apic_send_IPI_mask+0x10f/0x1a0 arch/x86/kernel/apic/x2apic_phys.c:52
 [<ffffffff810c511e>] x2apic_send_IPI_mask+0xe/0x10 arch/x86/kernel/apic/x2apic_cluster.c:79
 [<ffffffff810c1cfd>] arch_trigger_all_cpu_backtrace+0x33d/0x350 arch/x86/kernel/apic/hw_nmi.c:89
 [<ffffffff8123587e>] trigger_all_cpu_backtrace include/linux/nmi.h:43 [inline]
 [<ffffffff8123587e>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8123587e>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8123587e>] watchdog+0x47e/0x6c0 kernel/hung_task.c:238
 [<ffffffff811943fa>] kthread+0xea/0x100 drivers/block/aoe/aoecmd.c:1312
 [<ffffffff8264cbe2>] ret_from_fork+0x42/0x70 arch/x86/kernel/entry_64.S:639
Code: 00 55 89 f9 48 89 e5 0f 32 45 31 c0 48 89 d7 44 89 06 89 c6 5d 48 c1 e7 20 48 89 f8 48 09 f0 c3 90 55 89 f0 89 f9 48 89 e5 0f 30 <31> c0 5d c3 66 90 55 89 f9 48 89 e5 0f 33 48 89 d7 89 c1 5d 48