INFO: task syz-executor.5:23995 blocked for more than 143 seconds. Not tainted 5.0.0-next-20190305 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28840 23995 25477 0x00000004 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:285 [inline] rwsem_down_read_failed+0x213/0x420 kernel/locking/rwsem-xadd.c:302 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+0x49/0x90 kernel/locking/rwsem.c:26 __get_super.part.0+0x203/0x2e0 fs/super.c:788 __get_super include/linux/spinlock.h:329 [inline] get_super+0x2e/0x50 fs/super.c:817 fsync_bdev+0x19/0xd0 fs/block_dev.c:523 invalidate_partition+0x36/0x60 block/genhd.c:1581 drop_partitions block/partition-generic.c:443 [inline] rescan_partitions+0xef/0xa20 block/partition-generic.c:516 __blkdev_reread_part+0x1a2/0x230 block/ioctl.c:173 blkdev_reread_part+0x27/0x40 block/ioctl.c:193 loop_reread_partitions+0x1c/0x40 drivers/block/loop.c:633 loop_set_status+0xe57/0x1380 drivers/block/loop.c:1296 loop_set_status64+0xc2/0x120 drivers/block/loop.c:1416 lo_ioctl+0x8fc/0x2150 drivers/block/loop.c:1559 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0xee8/0x1c40 block/ioctl.c:605 block_ioctl+0xee/0x130 fs/block_dev.c:1931 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457c97 Code: Bad RIP value. RSP: 002b:00007f24de177a18 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f24de1786d4 RCX: 0000000000457c97 RDX: 00007f24de177ab0 RSI: 0000000000004c04 RDI: 0000000000000004 RBP: 0000000000000001 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000202 R12: 00007f24de1786d4 R13: 0000000000000003 R14: 0000000000000004 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by khungtaskd/1042: #0: 0000000092b7aee5 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5052 1 lock held by rsyslogd/7601: #0: 000000001cbfc361 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7691: #0: 000000005921b5d1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000909d443f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7692: #0: 00000000465d0f19 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007e5a3aff (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7693: #0: 00000000fac9ff53 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008295867e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7694: #0: 00000000fee8672e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000209326af (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7695: #0: 00000000710843d0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001b09f306 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7696: #0: 00000000c65c1896 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009bb5b336 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7697: #0: 000000002d52e16d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c380ea26 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.2/23992: 2 locks held by syz-executor.5/23995: #0: 00000000da2d81c8 (&bdev->bd_mutex){+.+.}, at: blkdev_reread_part+0x1f/0x40 block/ioctl.c:192 #1: 00000000b273aae6 (&type->s_umount_key#79){.+.+}, at: __get_super.part.0+0x203/0x2e0 fs/super.c:788 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.0.0-next-20190305 #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: