INFO: task syz-executor0:14530 blocked for more than 140 seconds. Not tainted 5.0.0-rc2-next-20190115 #12 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D27880 14530 23499 0x00000004 Call Trace: context_switch kernel/sched/core.c:2834 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3475 schedule+0xfe/0x350 kernel/sched/core.c:3519 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:280 [inline] rwsem_down_read_failed+0x360/0x6d0 kernel/locking/rwsem-xadd.c:297 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+0x9b/0x120 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_thawed+0x153/0x310 fs/super.c:825 get_super_thawed+0x18/0x20 fs/super.c:849 quotactl_block fs/quota/quota.c:818 [inline] kernel_quotactl+0x200/0x1810 fs/quota/quota.c:872 __do_sys_quotactl fs/quota/quota.c:893 [inline] __se_sys_quotactl fs/quota/quota.c:890 [inline] __x64_sys_quotactl+0x97/0xf0 fs/quota/quota.c:890 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ff6707fbc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000000 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff6707fc6d4 R13: 00000000004c4a21 R14: 00000000004d8198 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1039: #0: 000000008e7f6ab6 (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4408 1 lock held by udevd/3866: 1 lock held by rsyslogd/7702: #0: 0000000078867524 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1b3/0x1f0 fs/file.c:796 2 locks held by getty/7792: #0: 00000000acbaeaa2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c5c7263c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7793: #0: 000000003e004f71 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003c10cbbc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7794: #0: 00000000b40824a5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000000606023 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7795: #0: 000000006722d0bc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000098a918df (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7796: #0: 0000000014863258 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000ee12dc9a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7797: #0: 00000000a966fb12 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d4f578b0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7798: #0: 000000005701960d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000368083a4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 1 lock held by syz-executor1/11187: #0: 0000000063e4c18b (&rp->fetch_lock){+.+.}, at: mon_bin_read+0x60/0x640 drivers/usb/mon/mon_bin.c:813 2 locks held by syz-executor0/14519: 1 lock held by syz-executor0/14530: #0: 000000009ef3961a (&type->s_umount_key#78){.+.+}, at: __get_super.part.0+0x203/0x2e0 fs/super.c:788 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1039 Comm: khungtaskd Not tainted 5.0.0-rc2-next-20190115 #12 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+0x1db/0x2d0 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:203 [inline] watchdog+0xbbb/0x1170 kernel/hung_task.c:287 kthread+0x357/0x430 kernel/kthread.c:247 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: