INFO: task syz-executor.3:4814 blocked for more than 143 seconds. Not tainted 5.6.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28472 4814 1943 0x80004006 Call Trace: schedule+0xcd/0x2b0 kernel/sched/core.c:4156 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 filp_close+0xb4/0x160 fs/open.c:1252 close_files fs/file.c:388 [inline] put_files_struct fs/file.c:416 [inline] put_files_struct+0x1d8/0x2e0 fs/file.c:413 exit_files+0x7e/0xa0 fs/file.c:445 do_exit+0xb58/0x2c50 kernel/exit.c:796 do_group_exit+0x125/0x340 kernel/exit.c:899 get_signal+0x480/0x2470 kernel/signal.c:2734 do_signal+0x88/0x1490 arch/x86/kernel/signal.c:813 exit_to_usermode_loop+0x1a2/0x200 arch/x86/entry/common.c:160 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x4e0/0x5a0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459881 Code: 20 48 8d 6c 24 20 31 c0 48 8b 4c 24 38 eb 2d 48 89 44 24 18 48 8d 14 40 48 8b 5c 24 30 48 8d 14 d3 48 89 14 24 48 89 4c 24 08 aa de ff ff 48 8b 4c 24 10 48 8b 44 24 18 48 ff c0 48 83 f8 0e RSP: 002b:00007fff39000f70 EFLAGS: 00000293 ORIG_RAX: 0000000000000023 RAX: fffffffffffffdfc RBX: 0000000000013833 RCX: 0000000000459881 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fff39000f80 RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007fff39001070 R11: 0000000000000293 R12: 000000000075bf20 R13: 000000000075c9a0 R14: 00000000007601b0 R15: 000000000075bf2c INFO: task syz-executor.2:4821 blocked for more than 143 seconds. Not tainted 5.6.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28472 4821 1951 0x00000004 Call Trace: schedule+0xcd/0x2b0 kernel/sched/core.c:4156 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 filp_close+0xb4/0x160 fs/open.c:1252 __close_fd+0x133/0x200 fs/file.c:636 __do_sys_close fs/open.c:1271 [inline] __se_sys_close fs/open.c:1269 [inline] __x64_sys_close+0x69/0x100 fs/open.c:1269 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x414f51 Code: 00 31 c0 c3 0f 1f 44 00 00 48 c7 00 c0 4e 41 00 31 c0 c3 66 0f 1f 44 00 00 bf 69 30 44 00 b9 08 00 00 00 48 89 d6 f3 a6 74 1f 71 30 44 00 b9 0c 00 00 00 48 89 d6 f3 a6 75 1e 48 c7 00 a0 4e RSP: 002b:00007ffdff479480 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000414f51 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffdff479560 R11: 0000000000000293 R12: 000000000075bf20 R13: 0000000000012f27 R14: 00000000007601b0 R15: 000000000075bf2c INFO: task syz-executor.4:4825 blocked for more than 143 seconds. Not tainted 5.6.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28472 4825 1944 0x00000004 Call Trace: schedule+0xcd/0x2b0 kernel/sched/core.c:4156 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 filp_close+0xb4/0x160 fs/open.c:1252 __close_fd+0x133/0x200 fs/file.c:636 __do_sys_close fs/open.c:1271 [inline] __se_sys_close fs/open.c:1269 [inline] __x64_sys_close+0x69/0x100 fs/open.c:1269 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x414f51 Code: 00 31 c0 c3 0f 1f 44 00 00 48 c7 00 c0 4e 41 00 31 c0 c3 66 0f 1f 44 00 00 bf 69 30 44 00 b9 08 00 00 00 48 89 d6 f3 a6 74 1f 71 30 44 00 b9 0c 00 00 00 48 89 d6 f3 a6 75 1e 48 c7 00 a0 4e RSP: 002b:00007ffca0091720 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000414f51 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffca0091800 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 00000000007601b0 R15: 000000000075bfd4 INFO: task syz-executor.5:4826 blocked for more than 143 seconds. Not tainted 5.6.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28472 4826 1949 0x00000004 Call Trace: schedule+0xcd/0x2b0 kernel/sched/core.c:4156 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 filp_close+0xb4/0x160 fs/open.c:1252 __close_fd+0x133/0x200 fs/file.c:636 __do_sys_close fs/open.c:1271 [inline] __se_sys_close fs/open.c:1269 [inline] __x64_sys_close+0x69/0x100 fs/open.c:1269 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x414f51 Code: 00 31 c0 c3 0f 1f 44 00 00 48 c7 00 c0 4e 41 00 31 c0 c3 66 0f 1f 44 00 00 bf 69 30 44 00 b9 08 00 00 00 48 89 d6 f3 a6 74 1f 71 30 44 00 b9 0c 00 00 00 48 89 d6 f3 a6 75 1e 48 c7 00 a0 4e RSP: 002b:00007ffcdd175bd0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000414f51 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffcdd175cb0 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 00000000007601b0 R15: 000000000075bfd4 INFO: task syz-executor.0:4829 blocked for more than 144 seconds. Not tainted 5.6.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28472 4829 1947 0x00000004 Call Trace: schedule+0xcd/0x2b0 kernel/sched/core.c:4156 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 filp_close+0xb4/0x160 fs/open.c:1252 __close_fd+0x133/0x200 fs/file.c:636 __do_sys_close fs/open.c:1271 [inline] __se_sys_close fs/open.c:1269 [inline] __x64_sys_close+0x69/0x100 fs/open.c:1269 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x414f51 Code: 00 31 c0 c3 0f 1f 44 00 00 48 c7 00 c0 4e 41 00 31 c0 c3 66 0f 1f 44 00 00 bf 69 30 44 00 b9 08 00 00 00 48 89 d6 f3 a6 74 1f 71 30 44 00 b9 0c 00 00 00 48 89 d6 f3 a6 75 1e 48 c7 00 a0 4e RSP: 002b:00007ffd4a4fb2e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000414f51 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffd4a4fb3c0 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 00000000007601b0 R15: 000000000075bfd4 INFO: task syz-executor.1:4833 blocked for more than 144 seconds. Not tainted 5.6.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28472 4833 1953 0x00000004 Call Trace: schedule+0xcd/0x2b0 kernel/sched/core.c:4156 wdm_flush+0x2ea/0x3c0 drivers/usb/class/cdc-wdm.c:590 filp_close+0xb4/0x160 fs/open.c:1252 __close_fd+0x133/0x200 fs/file.c:636 __do_sys_close fs/open.c:1271 [inline] __se_sys_close fs/open.c:1269 [inline] __x64_sys_close+0x69/0x100 fs/open.c:1269 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x414f51 Code: 00 31 c0 c3 0f 1f 44 00 00 48 c7 00 c0 4e 41 00 31 c0 c3 66 0f 1f 44 00 00 bf 69 30 44 00 b9 08 00 00 00 48 89 d6 f3 a6 74 1f 71 30 44 00 b9 0c 00 00 00 48 89 d6 f3 a6 75 1e 48 c7 00 a0 4e RSP: 002b:00007ffd24cfd000 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000414f51 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffd24cfd0e0 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 00000000007601b0 R15: 000000000075bfd4 Showing all locks held in the system: 1 lock held by khungtaskd/22: #0: ffffffff87108ee0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5331 1 lock held by rsyslogd/1671: #0: ffff8881d13d8d60 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 2 locks held by getty/1761: #0: ffff8881d24c6090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1762: #0: ffff8881cf2b9090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004452e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1763: #0: ffff8881cf2bf090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004612e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1764: #0: ffff8881cf214090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000044d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1765: #0: ffff8881cf358090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004652e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1766: #0: ffff8881cf215090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004592e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1767: #0: ffff8881cff3f090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000042d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 22 Comm: khungtaskd Not tainted 5.6.0-rc1-syzkaller #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+0xef/0x16e lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1db/0x207 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+0xa99/0xfd0 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 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline] NMI backtrace for cpu 1 skipped: idling at default_idle+0x28/0x300 arch/x86/kernel/process.c:695