INFO: task syz-executor.1:2841 blocked for more than 143 seconds. Not tainted 5.3.0-rc5+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28520 2841 1862 0x00000004 Call Trace: schedule+0x9a/0x250 kernel/sched/core.c:3944 wdm_flush+0x18a/0x460 drivers/usb/class/cdc-wdm.c:590 filp_close+0xb4/0x160 fs/open.c:1166 __close_fd+0x133/0x200 fs/file.c:636 __do_sys_close fs/open.c:1185 [inline] __se_sys_close fs/open.c:1183 [inline] __x64_sys_close+0x69/0x100 fs/open.c:1183 do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413511 Code: 48 8b 40 30 83 80 00 01 00 00 ff 48 8b 6c 24 20 48 83 c4 28 c3 48 8d 05 07 31 24 00 48 89 04 24 48 c7 44 24 08 16 00 00 00 e8 <1b> 57 01 00 0f 0b 48 8d 05 15 00 22 00 48 89 04 24 48 c7 44 24 08 RSP: 002b:00007ffc1111a550 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000413511 RDX: fffffffffffffff7 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffc1111a630 R11: 0000000000000293 R12: 000000000075bf20 R13: 000000000000a6c3 R14: 0000000000760488 R15: ffffffffffffffff INFO: task syz-executor.5:2855 blocked for more than 143 seconds. Not tainted 5.3.0-rc5+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28168 2855 1871 0x00000004 Call Trace: schedule+0x9a/0x250 kernel/sched/core.c:3944 wdm_flush+0x18a/0x460 drivers/usb/class/cdc-wdm.c:590 filp_close+0xb4/0x160 fs/open.c:1166 __close_fd+0x133/0x200 fs/file.c:636 __do_sys_close fs/open.c:1185 [inline] __se_sys_close fs/open.c:1183 [inline] __x64_sys_close+0x69/0x100 fs/open.c:1183 do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413511 Code: 48 8b 40 30 83 80 00 01 00 00 ff 48 8b 6c 24 20 48 83 c4 28 c3 48 8d 05 07 31 24 00 48 89 04 24 48 c7 44 24 08 16 00 00 00 e8 <1b> 57 01 00 0f 0b 48 8d 05 15 00 22 00 48 89 04 24 48 c7 44 24 08 RSP: 002b:00007fff97397960 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000413511 RDX: fffffffffffffff7 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007fff97397a40 R11: 0000000000000293 R12: 000000000075bf20 R13: 000000000000a894 R14: 0000000000760488 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: 0000000084b787af (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x269 kernel/locking/lockdep.c:5254 1 lock held by rsyslogd/1604: 2 locks held by getty/1694: #0: 000000001a489867 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000a1f14aef (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1695: #0: 00000000b6d2253c (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000006c54f9ae (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1696: #0: 00000000393fdbe8 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000946abfea (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1697: #0: 00000000b4d6d459 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000b782f4b1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1698: #0: 000000005059df5d (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000009805da5f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1699: #0: 00000000bed26f3a (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000004ed38206 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 2 locks held by getty/1700: #0: 0000000040122501 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 00000000ddb347fb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x223/0x1ae0 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 5.3.0-rc5+ #1 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] NMI backtrace for cpu 0 skipped: idling at default_idle+0x28/0x2e0 arch/x86/kernel/process.c:580