INFO: task syz-executor.1:6635 blocked for more than 143 seconds. Not tainted 5.3.0+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29176 6635 1761 0x00000004 Call Trace: schedule+0xca/0x250 kernel/sched/core.c:4132 schedule_preempt_disabled+0xc/0x20 kernel/sched/core.c:4191 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x881/0x1360 kernel/locking/mutex.c:1103 misc_open+0x55/0x4a0 drivers/char/misc.c:107 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x494/0x1120 fs/open.c:797 do_last fs/namei.c:3408 [inline] path_openat+0x1430/0x3f50 fs/namei.c:3525 do_filp_open+0x1a1/0x280 fs/namei.c:3555 do_sys_open+0x3c0/0x580 fs/open.c:1089 do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459a09 Code: Bad RIP value. RSP: 002b:00007fdf29115c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459a09 RDX: 0000000000101401 RSI: 0000000020000140 RDI: ffffffffffffff9c RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdf291166d4 R13: 00000000004c6636 R14: 00000000004db708 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: ffffffff86eff3e0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x269 kernel/locking/lockdep.c:5335 1 lock held by rsyslogd/1601: #0: ffff8881d603e0e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:801 2 locks held by getty/1691: #0: ffff8881d96b2b10 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1692: #0: ffff8881d90c8910 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004592e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1693: #0: ffff8881d90e4d10 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004412e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1694: #0: ffff8881d90c8090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004612e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1695: #0: ffff8881d9092b10 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004652e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1696: #0: ffff8881d9122290 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc900004452e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1697: #0: ffff8881d96b3c10 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: ffffc9000042d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 6 locks held by kworker/1:4/3001: 2 locks held by syz-executor.1/6632: #0: ffffffff87130260 (misc_mtx){+.+.}, at: misc_open+0x55/0x4a0 drivers/char/misc.c:107 #1: ffffffff86ed9e20 (system_transition_mutex){+.+.}, at: snapshot_open+0x9c/0x4a0 kernel/power/user.c:52 1 lock held by syz-executor.1/6635: #0: ffffffff87130260 (misc_mtx){+.+.}, at: misc_open+0x55/0x4a0 drivers/char/misc.c:107 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 5.3.0+ #0 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+0xca/0x13e lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x55/0x96 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1c7 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0x9a4/0xe50 kernel/hung_task.c:289 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:trace_softirqs_off+0x1be/0x300 kernel/locking/lockdep.c:3536 Code: 00 fc ff df 89 ab fc 07 00 00 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 14 01 00 00 8b 15 ec 0c 0b 08 89 ab 30 08 00 00 85 d2 75 0c <65> 8b 05 03 07 dc 7e f6 c4 ff 74 5d 5b 5d 41 5c c3 e8 1c c5 b7 00 RSP: 0018:ffff8881db209f80 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffffff86e2b200 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000080000001 RDI: ffffffff86e2ba30 RBP: 00000000000b5325 R08: 0000000000000000 R09: 0000000000000001 R10: ffffed103b646574 R11: ffff8881db232ba3 R12: ffffffff86e2b200 R13: ffffffff86b6c6c0 R14: 0000000000000000 R15: ffffffff86e2b200 FS: 0000000000000000(0000) GS:ffff8881db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001d6b07000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __local_bh_disable_ip+0x34/0x40 kernel/softirq.c:129 local_bh_disable include/linux/bottom_half.h:19 [inline] irq_enter+0xac/0xd0 kernel/softirq.c:353 scheduler_ipi+0x24a/0x590 kernel/sched/core.c:2337 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:854 RIP: 0010:default_idle+0x28/0x2e0 arch/x86/kernel/process.c:581 Code: 90 90 41 56 41 55 65 44 8b 2d 24 d5 8e 7a 41 54 55 53 0f 1f 44 00 00 e8 86 ac d0 fb e9 07 00 00 00 0f 00 2d 5a 7b 4f 00 fb f4 <65> 44 8b 2d 00 d5 8e 7a 0f 1f 44 00 00 5b 5d 41 5c 41 5d 41 5e c3 RSP: 0018:ffffffff86e07da8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff02 RAX: 0000000000000007 RBX: ffffffff86e2b200 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffffffff86e2ba4c RBP: fffffbfff0dc5640 R08: ffffffff86e2b200 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x3b6/0x500 kernel/sched/idle.c:264 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:356 start_kernel+0x838/0x872 init/main.c:785 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241