hfs: can't find a HFS filesystem on dev loop0 INFO: task syz-executor.1:8634 blocked for more than 140 seconds. Not tainted 5.0.0-rc8+ #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D24448 8634 1 0x80000004 Call Trace: context_switch kernel/sched/core.c:2844 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3485 schedule+0x92/0x180 kernel/sched/core.c:3529 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3587 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1310 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 acct_get kernel/acct.c:161 [inline] slow_acct_process kernel/acct.c:577 [inline] acct_process+0x2e5/0x61e kernel/acct.c:605 do_exit+0x17df/0x2fd0 kernel/exit.c:865 do_group_exit+0x135/0x370 kernel/exit.c:979 get_signal+0x399/0x1d50 kernel/signal.c:2575 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x411fba Code: 48 89 ef e8 38 94 ff ff 85 c0 75 0c 48 c7 03 c0 22 41 00 e9 a6 fe ff ff be 4c 37 44 00 48 89 ef e8 1b 94 ff ff 85 c0 75 0c 48 03 f0 22 41 00 e9 89 fe ff ff 31 c0 48 89 ee bf 30 31 44 00 e8 RSP: 002b:00007ffef02db738 EFLAGS: 00000246 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 000000000251a99b RCX: 0000000000411fba RDX: 0000000040000000 RSI: 00007ffef02db770 RDI: ffffffffffffffff RBP: 00000000000001f1 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000251a940 R13: 000000000026d85d R14: 0000000000000080 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by khungtaskd/1041: #0: 00000000a99eccfe (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4389 1 lock held by udevd/3869: 1 lock held by rsyslogd/7519: #0: 0000000043553388 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:795 2 locks held by getty/7635: #0: 000000006720c106 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000e6cdd573 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7636: #0: 000000008c50d527 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000067e6d39a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7637: #0: 000000007c524420 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cf3c94b2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7638: #0: 00000000b38374e1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000066487a42 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7639: #0: 00000000fa2de302 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000005d705675 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7640: #0: 00000000ea2cfef9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000009a9c39a2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7641: #0: 000000009e8c43f2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000000c976a0c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 1 lock held by syz-executor.1/8634: #0: 00000000c5f0745b (&acct->lock#2){+.+.}, at: acct_get kernel/acct.c:161 [inline] #0: 00000000c5f0745b (&acct->lock#2){+.+.}, at: slow_acct_process kernel/acct.c:577 [inline] #0: 00000000c5f0745b (&acct->lock#2){+.+.}, at: acct_process+0x2e5/0x61e kernel/acct.c:605 3 locks held by syz-executor.1/11670: #0: 00000000c5f0745b (&acct->lock#2){+.+.}, at: acct_get kernel/acct.c:161 [inline] #0: 00000000c5f0745b (&acct->lock#2){+.+.}, at: slow_acct_process kernel/acct.c:577 [inline] #0: 00000000c5f0745b (&acct->lock#2){+.+.}, at: acct_process+0x2e5/0x61e kernel/acct.c:605 #1: 000000005496e77d (sb_writers#3){.+.+}, at: file_start_write_trylock include/linux/fs.h:2823 [inline] #1: 000000005496e77d (sb_writers#3){.+.+}, at: do_acct_process+0xf37/0x1150 kernel/acct.c:517 #2: 000000003346879c (&sb->s_type->i_mutex_key#9){+.+.}, at: inode_trylock include/linux/fs.h:777 [inline] #2: 000000003346879c (&sb->s_type->i_mutex_key#9){+.+.}, at: ext4_file_write_iter+0x250/0x1160 fs/ext4/file.c:232 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1041 Comm: khungtaskd Not tainted 5.0.0-rc8+ #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:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3869 Comm: udevd Not tainted 5.0.0-rc8+ #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:debug_lockdep_rcu_enabled+0x26/0xa0 kernel/rcu/update.c:248 Code: 00 00 00 00 48 c7 c0 a4 7c 5c 89 55 48 ba 00 00 00 00 00 fc ff df 48 89 c1 83 e0 07 48 89 e5 48 c1 e9 03 83 c0 03 0f b6 14 11 <38> d0 7c 04 84 d2 75 49 8b 15 c0 51 ff 07 85 d2 74 3b 48 c7 c0 b8 RSP: 0018:ffff888097c67b10 EFLAGS: 00000002 RAX: 0000000000000007 RBX: 1ffff11012f8cf6a RCX: 1ffffffff12b8f94 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888097c5abbc RBP: ffff888097c67b10 R08: 0000000000000000 R09: ffffed1012f8cf6e R10: ffffed1012f8cf6d R11: 0000000000000003 R12: ffff888097ce9d98 R13: ffffffff81c2507f R14: ffff888097c5a340 R15: ffff888097c67bb0 FS: 00007f45a0c5f7a0(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000098110000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x5d6/0xa00 kernel/locking/lockdep.c:3859 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:166 [inline] _raw_spin_unlock_irq+0x1b/0x90 kernel/locking/spinlock.c:192 spin_unlock_irq include/linux/spinlock.h:379 [inline] ep_scan_ready_list+0x77f/0xb30 fs/eventpoll.c:752 ep_send_events fs/eventpoll.c:1715 [inline] ep_poll+0x1f9/0xe50 fs/eventpoll.c:1852 do_epoll_wait+0x1b3/0x200 fs/eventpoll.c:2216 __do_sys_epoll_wait fs/eventpoll.c:2226 [inline] __se_sys_epoll_wait fs/eventpoll.c:2223 [inline] __x64_sys_epoll_wait+0x97/0xf0 fs/eventpoll.c:2223 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f45a0373943 Code: 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 83 3d b5 dc 2a 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 3b c4 00 00 48 89 04 24 RSP: 002b:00007ffd2d0c9af8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007f45a0373943 RDX: 0000000000000008 RSI: 00007ffd2d0c9bf0 RDI: 000000000000000a RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000bb8 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00000000016fcb30 R15: 00000000016cb250