IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready random: crng init done INFO: task syz-executor3:13421 blocked for more than 120 seconds. Not tainted 4.16.0-rc7+ #9 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D24672 13421 4481 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 schedule+0xf5/0x430 kernel/sched/core.c:3499 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x401/0x6e0 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xa4/0x150 kernel/locking/rwsem.c:26 __get_super.part.9+0x1d3/0x280 fs/super.c:663 __get_super include/linux/spinlock.h:310 [inline] get_super+0x2d/0x40 fs/super.c:692 fsync_bdev+0x19/0x80 fs/block_dev.c:468 invalidate_partition+0x35/0x60 block/genhd.c:1566 drop_partitions.isra.12+0xcd/0x1d0 block/partition-generic.c:440 rescan_partitions+0x72/0x900 block/partition-generic.c:513 __blkdev_reread_part+0x15f/0x1e0 block/ioctl.c:173 blkdev_reread_part+0x26/0x40 block/ioctl.c:193 loop_reread_partitions+0x12f/0x1a0 drivers/block/loop.c:619 loop_set_status+0x9bb/0xf60 drivers/block/loop.c:1161 loop_set_status64+0x9d/0x110 drivers/block/loop.c:1271 lo_ioctl+0xd86/0x1b70 drivers/block/loop.c:1381 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x1759/0x1e00 block/ioctl.c:601 block_ioctl+0xde/0x120 fs/block_dev.c:1875 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x454e79 RSP: 002b:00007fda691eec68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fda691ef6d4 RCX: 0000000000454e79 RDX: 00000000200001c0 RSI: 0000000000004c04 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000287 R14: 00000000006f5d48 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/878: #0: (rcu_read_lock){....}, at: [<000000004cf2ddac>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000004cf2ddac>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000fc5e2248>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by getty/4404: #0: (&tty->ldisc_sem){++++}, at: [<00000000c5139392>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003da58a6e>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4405: #0: (&tty->ldisc_sem){++++}, at: [<00000000c5139392>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003da58a6e>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4406: #0: (&tty->ldisc_sem){++++}, at: [<00000000c5139392>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003da58a6e>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4407: #0: (&tty->ldisc_sem){++++}, at: [<00000000c5139392>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003da58a6e>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4408: #0: (&tty->ldisc_sem){++++}, at: [<00000000c5139392>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003da58a6e>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4409: #0: (&tty->ldisc_sem){++++}, at: [<00000000c5139392>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003da58a6e>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4410: #0: (&tty->ldisc_sem){++++}, at: [<00000000c5139392>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003da58a6e>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 3 locks held by syz-executor3/13421: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000834f78af>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 #1: (&bdev->bd_mutex){+.+.}, at: [<0000000003605603>] blkdev_reread_part+0x1e/0x40 block/ioctl.c:192 #2: (&type->s_umount_key#77){.+.+}, at: [<0000000077701649>] __get_super.part.9+0x1d3/0x280 fs/super.c:663 1 lock held by syz-executor3/13464: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000c39e77db>] __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 1 lock held by syz-executor3/13466: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000834f78af>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 1 lock held by syz-executor2/13423: #0: (&bdev->bd_mutex){+.+.}, at: [<0000000032c86bf7>] blkdev_put+0x2a/0x4f0 fs/block_dev.c:1808 2 locks held by syz-executor0/13428: #0: (&type->s_umount_key#76/1){+.+.}, at: [<00000000d25ba33a>] alloc_super fs/super.c:211 [inline] #0: (&type->s_umount_key#76/1){+.+.}, at: [<00000000d25ba33a>] sget_userns+0x3a1/0xe40 fs/super.c:502 #1: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000834f78af>] lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 1 lock held by syz-executor0/13465: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000c39e77db>] __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 1 lock held by blkid/13434: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000c39e77db>] __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 1 lock held by syz-executor2/13638: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000c39e77db>] __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 1 lock held by syz-executor2/13639: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000c39e77db>] __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 878 Comm: khungtaskd Not tainted 4.16.0-rc7+ #9 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [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+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54