====================================================== WARNING: possible circular locking dependency detected 4.13.0-rc6-next-20170823+ #7 Not tainted ------------------------------------------------------ syz-executor4/3561 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){++++}, at: [] get_online_cpus include/linux/cpu.h:126 [inline] (cpu_hotplug_lock.rw_sem){++++}, at: [] flush_all_backlogs net/core/dev.c:4592 [inline] (cpu_hotplug_lock.rw_sem){++++}, at: [] rollback_registered_many+0x587/0xe80 net/core/dev.c:7127 but task is already holding lock: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (rtnl_mutex){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x3286/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0x16f/0x1870 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 reg_todo+0xc6/0xbe0 net/wireless/reg.c:2337 process_one_work+0xbfd/0x1be0 kernel/workqueue.c:2098 worker_thread+0x223/0x1860 kernel/workqueue.c:2233 kthread+0x39c/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 -> #2 (reg_work){+.+.}: process_one_work+0xba5/0x1be0 kernel/workqueue.c:2095 worker_thread+0x223/0x1860 kernel/workqueue.c:2233 kthread+0x39c/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 0xffffffffffffffff -> #1 ((complete)&rcu.completion){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x3286/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 complete_acquire include/linux/completion.h:39 [inline] __wait_for_common kernel/sched/completion.c:108 [inline] wait_for_common kernel/sched/completion.c:122 [inline] wait_for_completion+0xc8/0x770 kernel/sched/completion.c:143 __synchronize_srcu+0x1b5/0x250 kernel/rcu/srcutree.c:898 synchronize_srcu_expedited kernel/rcu/srcutree.c:923 [inline] synchronize_srcu+0x1a3/0x560 kernel/rcu/srcutree.c:974 quarantine_remove_cache+0xd7/0xf0 mm/kasan/quarantine.c:327 kasan_cache_shrink+0x9/0x10 mm/kasan/kasan.c:380 kmem_cache_shrink+0x15/0x30 mm/slab_common.c:857 acpi_os_purge_cache+0x15/0x20 drivers/acpi/osl.c:1560 acpi_purge_cached_objects+0x38/0xc9 drivers/acpi/acpica/utxface.c:271 acpi_initialize_objects+0xc5/0x112 drivers/acpi/acpica/utxfinit.c:302 acpi_bus_init drivers/acpi/bus.c:1131 [inline] acpi_init+0x23c/0x8e6 drivers/acpi/bus.c:1220 do_one_initcall+0x9e/0x330 init/main.c:825 do_initcall_level init/main.c:891 [inline] do_initcalls init/main.c:899 [inline] do_basic_setup init/main.c:917 [inline] kernel_init_freeable+0x46e/0x526 init/main.c:1067 kernel_init+0x13/0x172 init/main.c:992 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 -> #0 (cpu_hotplug_lock.rw_sem){++++}: check_prev_add+0x865/0x1520 kernel/locking/lockdep.c:1894 check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x3286/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:35 [inline] percpu_down_read include/linux/percpu-rwsem.h:58 [inline] cpus_read_lock+0x42/0x90 kernel/cpu.c:218 get_online_cpus include/linux/cpu.h:126 [inline] flush_all_backlogs net/core/dev.c:4592 [inline] rollback_registered_many+0x587/0xe80 net/core/dev.c:7127 rollback_registered+0x1be/0x3c0 net/core/dev.c:7183 unregister_netdevice_queue+0x2e3/0x5d0 net/core/dev.c:8171 unregister_netdevice include/linux/netdevice.h:2428 [inline] __tun_detach+0x1020/0x1390 drivers/net/tun.c:576 tun_detach drivers/net/tun.c:587 [inline] tun_chr_close+0x44/0x60 drivers/net/tun.c:2595 __fput+0x333/0x7f0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:246 task_work_run+0x199/0x270 kernel/task_work.c:112 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x2a6/0x300 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath+0x42f/0x500 arch/x86/entry/common.c:266 entry_SYSCALL_64_fastpath+0xbc/0xbe other info that might help us debug this: Chain exists of: cpu_hotplug_lock.rw_sem --> reg_work --> rtnl_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(reg_work); lock(rtnl_mutex); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** 1 lock held by syz-executor4/3561: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:72 stack backtrace: CPU: 3 PID: 3561 Comm: syz-executor4 Not tainted 4.13.0-rc6-next-20170823+ #7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_circular_bug+0x503/0x710 kernel/locking/lockdep.c:1259 check_prev_add+0x865/0x1520 kernel/locking/lockdep.c:1894 check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x3286/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:35 [inline] percpu_down_read include/linux/percpu-rwsem.h:58 [inline] cpus_read_lock+0x42/0x90 kernel/cpu.c:218 get_online_cpus include/linux/cpu.h:126 [inline] flush_all_backlogs net/core/dev.c:4592 [inline] rollback_registered_many+0x587/0xe80 net/core/dev.c:7127 rollback_registered+0x1be/0x3c0 net/core/dev.c:7183 unregister_netdevice_queue+0x2e3/0x5d0 net/core/dev.c:8171 unregister_netdevice include/linux/netdevice.h:2428 [inline] __tun_detach+0x1020/0x1390 drivers/net/tun.c:576 tun_detach drivers/net/tun.c:587 [inline] tun_chr_close+0x44/0x60 drivers/net/tun.c:2595 __fput+0x333/0x7f0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:246 task_work_run+0x199/0x270 kernel/task_work.c:112 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x2a6/0x300 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath+0x42f/0x500 arch/x86/entry/common.c:266 entry_SYSCALL_64_fastpath+0xbc/0xbe RIP: 0033:0x446749 RSP: 002b:00007fc85097dc08 EFLAGS: 00000292 ORIG_RAX: 0000000000000021 RAX: 0000000000000005 RBX: 0000000000000016 RCX: 0000000000446749 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000016 RBP: 00000000007080a8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 00000000ffffffff R13: 00000000000004e0 R14: 00000000006e25a0 R15: 0000000000000005 sctp: [Deprecated]: syz-executor1 (pid 3593) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead sctp: [Deprecated]: syz-executor1 (pid 3607) Use of struct sctp_assoc_value in delayed_ack socket option. Use struct sctp_sack_info instead netlink: 13 bytes leftover after parsing attributes in process `syz-executor2'. Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable netlink: 13 bytes leftover after parsing attributes in process `syz-executor2'. print_req_error: I/O error, dev loop7, sector 0 Buffer I/O error on dev loop7, logical block 0, lost async page write print_req_error: I/O error, dev loop7, sector 8 Buffer I/O error on dev loop7, logical block 1, lost async page write print_req_error: I/O error, dev loop7, sector 16 Buffer I/O error on dev loop7, logical block 2, lost async page write print_req_error: I/O error, dev loop7, sector 24 Buffer I/O error on dev loop7, logical block 3, lost async page write print_req_error: I/O error, dev loop7, sector 32 Buffer I/O error on dev loop7, logical block 4, lost async page write print_req_error: I/O error, dev loop7, sector 40 Buffer I/O error on dev loop7, logical block 5, lost async page write print_req_error: I/O error, dev loop7, sector 48 Buffer I/O error on dev loop7, logical block 6, lost async page write print_req_error: I/O error, dev loop7, sector 56 Buffer I/O error on dev loop7, logical block 7, lost async page write print_req_error: I/O error, dev loop7, sector 64 Buffer I/O error on dev loop7, logical block 8, lost async page write print_req_error: I/O error, dev loop7, sector 72 Buffer I/O error on dev loop7, logical block 9, lost async page write netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor5'. TCP: request_sock_TCP: Possible SYN flooding on port 20024. Sending cookies. Check SNMP counters. netlink: 1 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor2'. RDS: rds_bind could not find a transport for 172.20.5.187, load rds_tcp or rds_rdma? RDS: rds_bind could not find a transport for 172.20.5.187, load rds_tcp or rds_rdma? raw_sendmsg: syz-executor4 forgot to set AF_INET. Fix it! *** Guest State *** CR0: actual=0x0000000000000030, shadow=0x0000000060000010, gh_mask=fffffffffffffff7 CR4: actual=0x0000000000002050, shadow=0x0000000000000000, gh_mask=fffffffffffff871 CR3 = 0x00000000fffbc000 RSP = 0x0000000000000000 RIP = 0x000000000000fff0 RFLAGS=0x00010000 DR7 = 0x0000000000000400 Sysenter RSP=0000000000000000 CS:RIP=0000:0000000000000000 CS: sel=0xf000, attr=0x0009b, limit=0x0000ffff, base=0x00000000ffff0000 DS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 SS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 ES: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 FS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GS: sel=0x0000, attr=0x00093, limit=0x0000ffff, base=0x0000000000000000 GDTR: limit=0x0000ffff, base=0x0000000000000000 LDTR: sel=0x0000, attr=0x00082, limit=0x0000ffff, base=0x0000000000000000 IDTR: limit=0x0000ffff, base=0x0000000000000000 TR: sel=0x0000, attr=0x0008b, limit=0x0000ffff, base=0x0000000000000000 EFER = 0x0000000000000000 PAT = 0x0007040600070406 DebugCtl = 0x0000000000000000 DebugExceptions = 0x0000000000000000 BndCfgS = 0x0000000000000000 Interruptibility = 0000000a ActivityState = 00000000 *** Host State *** RIP = 0xffffffff811b6277 RSP = 0xffff88002bfdf4c8 CS=0010 SS=0018 DS=0000 ES=0000 FS=0000 GS=0000 TR=0040 FSBase=00007fa86d29c700 GSBase=ffff88003ed00000 TRBase=ffff88003ed23100 GDTBase=ffffffffff576000 IDTBase=ffffffffff57b000 CR0=0000000080050033 CR3=000000006ad8e000 CR4=00000000000026e0 Sysenter RSP=0000000000000000 CS:RIP=0010:ffffffff84d9d270 EFER = 0x0000000000000d01 PAT = 0x0007040600070406 *** Control State *** PinBased=0000003f CPUBased=b6a1edfa SecondaryExec=001000e3 EntryControls=0001d1ff ExitControls=00afefff ExceptionBitmap=00060042 PFECmask=00000000 PFECmatch=00000000 VMEntry: intr_info=80000b05 errcode=00000008 ilen=00000000 VMExit: intr_info=00000000 errcode=00000000 ilen=00000000 reason=80000021 qualification=0000000000000000 IDTVectoring: info=00000000 errcode=00000000 TSC Offset = 0xffffffcbb7c9e65c TPR Threshold = 0x00 EPT pointer = 0x000000003bba201e Virtual processor ID = 0x0001 netlink: 5 bytes leftover after parsing attributes in process `syz-executor4'. IPv6: NLM_F_REPLACE set, but no existing node found! netlink: 5 bytes leftover after parsing attributes in process `syz-executor4'. IPv6: NLM_F_REPLACE set, but no existing node found! capability: warning: `syz-executor5' uses 32-bit capabilities (legacy support in use) QAT: Invalid ioctl netlink: 11 bytes leftover after parsing attributes in process `syz-executor5'. QAT: Invalid ioctl xprt_adjust_timeout: rq_timeout = 0! xprt_adjust_timeout: rq_timeout = 0! 8021q: VLANs not supported on lo 8021q: VLANs not supported on lo kvm [4083]: vcpu0, guest rIP: 0x910f Hyper-V uhandled wrmsr: 0x4000008f data 0x4000f1 kvm [4083]: vcpu0, guest rIP: 0x910f Hyper-V uhandled wrmsr: 0x4000008e data 0x4000f2 kvm [4083]: vcpu0, guest rIP: 0x910f Hyper-V uhandled wrmsr: 0x4000008d data 0x4000f3 kvm [4083]: vcpu0, guest rIP: 0x910f Hyper-V uhandled wrmsr: 0x4000008c data 0x4000f4 kvm [4083]: vcpu0, guest rIP: 0x910f Hyper-V uhandled wrmsr: 0x4000008b data 0x4000f5 kvm [4083]: vcpu0, guest rIP: 0x910f Hyper-V uhandled wrmsr: 0x4000008a data 0x4000f6 kvm [4083]: vcpu0, guest rIP: 0x910f Hyper-V uhandled wrmsr: 0x40000089 data 0x4000f7 kvm [4083]: vcpu0, guest rIP: 0x910f Hyper-V uhandled wrmsr: 0x40000088 data 0x4000f8 kvm [4083]: vcpu0, guest rIP: 0x910f Hyper-V uhandled wrmsr: 0x40000087 data 0x4000f9 kvm [4083]: vcpu0, guest rIP: 0x910f Hyper-V uhandled wrmsr: 0x40000086 data 0x4000fa