INFO: task syz-executor.1:27656 blocked for more than 143 seconds. Not tainted 5.1.0-rc5-next-20190418 #28 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28336 27656 7851 0x00004004 Call Trace: context_switch kernel/sched/core.c:2817 [inline] __schedule+0x7d1/0x15c0 kernel/sched/core.c:3444 schedule+0xa8/0x260 kernel/sched/core.c:3508 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:585 [inline] rwsem_down_write_failed+0x7a1/0xc60 kernel/locking/rwsem-xadd.c:617 __down_write kernel/locking/rwsem.h:226 [inline] down_write+0x93/0xa0 kernel/locking/rwsem.c:68 grab_super+0xb4/0x290 fs/super.c:385 sget_userns+0x1ab/0x560 fs/super.c:601 sget+0x10c/0x150 fs/super.c:660 mount_bdev+0xff/0x3c0 fs/super.c:1319 udf_mount+0x35/0x40 fs/udf/super.c:131 legacy_get_tree+0xf2/0x200 fs/fs_context.c:584 vfs_get_tree+0x123/0x450 fs/super.c:1481 do_new_mount fs/namespace.c:2622 [inline] do_mount+0x1436/0x2c40 fs/namespace.c:2942 ksys_mount+0xdb/0x150 fs/namespace.c:3151 __do_sys_mount fs/namespace.c:3165 [inline] __se_sys_mount fs/namespace.c:3162 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3162 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458c29 Code: Bad RIP value. RSP: 002b:00007f1941f1fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000458c29 RDX: 0000000020000100 RSI: 0000000020000080 RDI: 00000000200000c0 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1941f206d4 R13: 00000000004c4c0e R14: 00000000004d8888 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1043: #0: 000000004b5e49ad (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5046 1 lock held by rsyslogd/7700: #0: 000000005fbcf41d (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7812: #0: 00000000936514e8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000e24993bf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7813: #0: 00000000c8be3244 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000093d0587f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7814: #0: 000000002273653a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000007909759c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7815: #0: 000000007e7bea57 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000004eff0110 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7816: #0: 00000000de8832a2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000bd6cd2ff (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7817: #0: 00000000a118fdd2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000197bdd83 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7818: #0: 00000000339d749a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003c25757d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.1/27649: 2 locks held by syz-executor.1/27656: #0: 00000000fa727889 (&bdev->bd_fsfreeze_mutex){+.+.}, at: mount_bdev+0x93/0x3c0 fs/super.c:1313 #1: 00000000a61d97d8 (&type->s_umount_key#83){+.+.}, at: grab_super+0xb4/0x290 fs/super.c:385 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1043 Comm: khungtaskd Not tainted 5.1.0-rc5-next-20190418 #28 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:254 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: