netlink: 16 bytes leftover after parsing attributes in process `syz-executor1'. INFO: task syz-executor4:9515 blocked for more than 120 seconds. Not tainted 4.15.0-rc1+ #204 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D20544 9515 3350 0x00000004 Call Trace: context_switch kernel/sched/core.c:2799 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3375 schedule+0xf5/0x430 kernel/sched/core.c:3434 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3492 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0xaad/0x1a80 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 blkdev_reread_part+0x1e/0x40 block/ioctl.c:192 loop_reread_partitions+0x12f/0x1a0 drivers/block/loop.c:619 loop_set_status+0x9ba/0xf60 drivers/block/loop.c:1161 loop_set_status64+0x95/0x100 drivers/block/loop.c:1271 lo_ioctl+0xd98/0x1b90 drivers/block/loop.c:1381 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x1759/0x1e00 block/ioctl.c:601 block_ioctl+0xea/0x130 fs/block_dev.c:1860 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:686 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x4529d9 RSP: 002b:00007f09e88bbc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 00000000004529d9 RDX: 0000000020a8ff18 RSI: 0000000000004c04 RDI: 0000000000000016 RBP: 0000000000000540 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f4ea0 R13: 00000000ffffffff R14: 00007f09e88bc6d4 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/674: #0: (rcu_read_lock){....}, at: [<00000000396cd1a8>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000396cd1a8>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<0000000096a7b7f4>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4554 2 locks held by getty/3054: #0: (&tty->ldisc_sem){++++}, at: [<00000000c828faca>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a7f4335e>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3055: #0: (&tty->ldisc_sem){++++}, at: [<00000000c828faca>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a7f4335e>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3056: #0: (&tty->ldisc_sem){++++}, at: [<00000000c828faca>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a7f4335e>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3057: #0: (&tty->ldisc_sem){++++}, at: [<00000000c828faca>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a7f4335e>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3058: #0: (&tty->ldisc_sem){++++}, at: [<00000000c828faca>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a7f4335e>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3059: #0: (&tty->ldisc_sem){++++}, at: [<00000000c828faca>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a7f4335e>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3060: #0: (&tty->ldisc_sem){++++}, at: [<00000000c828faca>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000a7f4335e>] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by syz-executor4/9515: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000e7502bc1>] lo_ioctl+0x8b/0x1b90 drivers/block/loop.c:1355 #1: (&bdev->bd_mutex){+.+.}, at: [<00000000435b4ba4>] blkdev_reread_part+0x1e/0x40 block/ioctl.c:192 1 lock held by syz-executor4/9522: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000e7502bc1>] lo_ioctl+0x8b/0x1b90 drivers/block/loop.c:1355 1 lock held by syz-executor4/9541: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b174d747>] __blkdev_get+0x158/0x10e0 fs/block_dev.c:1439 1 lock held by syz-executor7/9521: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000e7502bc1>] lo_ioctl+0x8b/0x1b90 drivers/block/loop.c:1355 1 lock held by syz-executor7/9525: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000e7502bc1>] lo_ioctl+0x8b/0x1b90 drivers/block/loop.c:1355 1 lock held by syz-executor7/9547: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b174d747>] __blkdev_get+0x158/0x10e0 fs/block_dev.c:1439 2 locks held by blkid/9520: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b174d747>] __blkdev_get+0x158/0x10e0 fs/block_dev.c:1439 #1: (loop_index_mutex){+.+.}, at: [<000000005253b538>] lo_open+0x1b/0xa0 drivers/block/loop.c:1571 1 lock held by syz-executor0/9527: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 1 lock held by syz-executor0/9554: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 2 locks held by syz-executor5/9526: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [<000000001a5f807e>] loop_control_ioctl+0x1a7/0x490 drivers/block/loop.c:1946 1 lock held by syz-executor5/9542: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 1 lock held by syz-executor2/9530: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 1 lock held by syz-executor2/9564: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 1 lock held by syz-executor6/9534: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 1 lock held by syz-executor6/9556: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 1 lock held by syz-executor3/9539: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 1 lock held by syz-executor3/9565: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 1 lock held by syz-executor1/9543: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 1 lock held by syz-executor1/9566: #0: (loop_index_mutex){+.+.}, at: [<00000000268a88d7>] loop_control_ioctl+0x89/0x490 drivers/block/loop.c:1932 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 674 Comm: khungtaskd Not tainted 4.15.0-rc1+ #204 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+0x194/0x257 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 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+0x37a/0x440 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:441 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