netlink: 5 bytes leftover after parsing attributes in process `syz-executor2'. INFO: task blkid:9748 blocked for more than 120 seconds. Not tainted 4.14.0-rc4-next-20171009+ #33 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D23416 9748 1616 0x00000004 Call Trace: context_switch kernel/sched/core.c:2798 [inline] __schedule+0x8eb/0x2080 kernel/sched/core.c:3374 schedule+0xf5/0x430 kernel/sched/core.c:3433 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3491 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0xadb/0x19d0 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 __blkdev_get+0x158/0xf90 fs/block_dev.c:1449 blkdev_get+0x3a1/0xad0 fs/block_dev.c:1601 blkdev_open+0x1e4/0x270 fs/block_dev.c:1759 do_dentry_open+0x67f/0xd70 fs/open.c:752 vfs_open+0x107/0x230 fs/open.c:866 do_last fs/namei.c:3387 [inline] path_openat+0x1157/0x3520 fs/namei.c:3527 do_filp_open+0x25b/0x3b0 fs/namei.c:3562 do_sys_open+0x502/0x6d0 fs/open.c:1059 SYSC_open fs/open.c:1077 [inline] SyS_open+0x2d/0x40 fs/open.c:1072 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x7fb70c765120 RSP: 002b:00007ffd88077c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb70c765120 RDX: 00007ffd88078f34 RSI: 0000000000000000 RDI: 00007ffd88078f34 RBP: 0000000000000082 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403738 R13: 0000000000000001 R14: 0000000000000000 R15: 00007fb70ca3ba20 Showing all locks held in the system: 2 locks held by khungtaskd/643: #0: (rcu_read_lock){....}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.?.?}, at: [] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4552 2 locks held by getty/2958: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2959: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2960: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2961: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2962: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2963: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 2 locks held by getty/2964: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2133 3 locks held by kworker/u4:4/3262: #0: ("writeback"){+.+.}, at: [] __write_once_size include/linux/compiler.h:305 [inline] #0: ("writeback"){+.+.}, at: [] atomic64_set arch/x86/include/asm/atomic64_64.h:33 [inline] #0: ("writeback"){+.+.}, at: [] atomic_long_set include/asm-generic/atomic-long.h:56 [inline] #0: ("writeback"){+.+.}, at: [] set_work_data kernel/workqueue.c:617 [inline] #0: ("writeback"){+.+.}, at: [] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ("writeback"){+.+.}, at: [] process_one_work+0xad4/0x1bd0 kernel/workqueue.c:2089 #1: ((&(&wb->dwork)->work)){+.+.}, at: [] process_one_work+0xb2c/0x1bd0 kernel/workqueue.c:2093 #2: (&type->s_umount_key#30){.+.+}, at: [] trylock_super+0x20/0x100 fs/super.c:391 1 lock held by syz-executor2/9739: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xa7/0x7c0 fs/block_dev.c:1767 1 lock held by blkid/9748: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x158/0xf90 fs/block_dev.c:1449 1 lock held by syz-executor2/9792: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x158/0xf90 fs/block_dev.c:1449 1 lock held by syz-executor2/9793: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x158/0xf90 fs/block_dev.c:1449 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 643 Comm: khungtaskd Not tainted 4.14.0-rc4-next-20171009+ #33 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 nmi_cpu_backtrace+0x20e/0x240 lib/nmi_backtrace.c:102 nmi_trigger_cpumask_backtrace+0x122/0x180 lib/nmi_backtrace.c:61 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 trigger_all_cpu_backtrace include/linux/nmi.h:137 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x3c9/0x4b0 kernel/kthread.c:242 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-rc4-next-20171009+ #33 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffffffff8582f3c0 task.stack: ffffffff85800000 RIP: 0010:__read_once_size include/linux/compiler.h:276 [inline] RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:2366 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:2386 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:2440 [inline] RIP: 0010:__lock_acquire+0x19bc/0x4620 kernel/locking/lockdep.c:3498 RSP: 0018:ffff8801db206cc8 EFLAGS: 00000046 RAX: ffffffff8632b088 RBX: ffffffff8582fc58 RCX: dffffc0000000000 RDX: ffffed003b640e0c RSI: ffff8801db207060 RDI: 1ffffffff0c65611 RBP: ffff8801db2071c8 R08: 9dd28c6188bbd6db R09: 1ffffffff0c65613 R10: 0000000000000020 R11: ffffffff86e2ace0 R12: ffffffff8582f3c0 R13: 00000000000017ad R14: 0000000000000001 R15: ffffffff8582fc70 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c43fe33000 CR3: 00000001cebf3000 CR4: 00000000001406f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000020001000 DR3: 0000000020000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x96/0xc0 kernel/locking/spinlock.c:159 rq_lock_irqsave kernel/sched/sched.h:1721 [inline] update_blocked_averages+0x1cb/0x39c0 kernel/sched/fair.c:7309 rebalance_domains+0x145/0xcc0 kernel/sched/fair.c:9085 run_rebalance_domains+0x378/0x770 kernel/sched/fair.c:9346 __do_softirq+0x29d/0xbb2 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1d3/0x210 kernel/softirq.c:405 scheduler_ipi+0x165/0x460 kernel/sched/core.c:1802 smp_reschedule_interrupt+0xe6/0x670 arch/x86/kernel/smp.c:277 reschedule_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:794 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:53 RSP: 0018:ffffffff85807d08 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffffffff0b00fa4 RCX: 0000000000000000 RDX: 1ffffffff0b19708 RSI: 0000000000000001 RDI: ffffffff858cb840 RBP: ffffffff85807d08 R08: ffffffff8576ea60 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff858cb830 R13: ffffffff85807dc0 R14: 0000000000000000 R15: ffffffff858cb820 arch_safe_halt arch/x86/include/asm/paravirt.h:93 [inline] default_idle+0xbf/0x460 arch/x86/kernel/process.c:341 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:332 default_idle_call+0x36/0x90 kernel/sched/idle.c:98 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x24e/0x3b0 kernel/sched/idle.c:246 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:351 rest_init+0xed/0xf0 init/main.c:435 start_kernel+0x73a/0x760 init/main.c:713 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:377 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:358 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:238 Code: 10 49 89 f9 49 c1 e9 03 41 80 3c 09 00 0f 85 86 2b 00 00 4c 3b 40 10 0f 84 2f ef ff ff 48 89 c7 c6 02 00 48 c1 ef 03 80 3c 0f 00 <0f> 85 07 2b 00 00 80 3a 00 48 8b 00 0f 85 9a 2a 00 00 48 85 c0