INFO: task syz-executor212:1809 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-executor212 D26504 1809 1808 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: 0033:0x445669 Code: Bad RIP value. RSP: 002b:00007ffdbfbcdf08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 0000000000445669 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00000000004a6b70 R08: 000000000000000f R09: 0000000120080522 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402880 R13: 0000000000402910 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor212:1810 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-executor212 D28472 1810 1807 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: 0033:0x445669 Code: Bad RIP value. RSP: 002b:00007ffdbfbcdf08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 0000000000445669 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00000000004a6b70 R08: 000000000000000f R09: 0000000120080522 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402880 R13: 0000000000402910 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor212:1811 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-executor212 D28472 1811 1805 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: 0033:0x401860 Code: 65 74 68 6f 73 74 6e 61 6d 65 00 63 68 6f 77 6e 00 66 77 72 69 74 65 00 66 72 65 61 64 00 67 65 74 65 75 69 64 00 77 61 69 74 <70> 69 64 00 6c 6f 63 61 6c 74 69 6d 65 00 73 74 72 63 68 72 00 66 RSP: 002b:00007ffdbfbcde58 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: 0000000000000004 RBX: 0000000000000000 RCX: 0000000000401860 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007ffdbfbcde70 RBP: 00000000004a6b70 R08: 0000000000000000 R09: 000000000000000f R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000402880 R13: 0000000000402910 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor212:1813 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-executor212 D28472 1813 1804 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: 0033:0x401800 Code: 67 63 6f 6d 70 00 6f 70 74 61 72 67 00 73 74 64 65 72 72 00 5f 5f 73 6e 70 72 69 6e 74 66 5f 63 68 6b 00 73 65 74 65 75 69 64 <00> 67 65 74 75 69 64 00 67 65 74 65 67 69 64 00 65 78 65 63 76 70 RSP: 002b:00007ffdbfbcdf08 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000401800 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00000000004a6b70 R08: 000000000000000f R09: 0000000120080522 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402880 R13: 0000000000402910 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor212:1814 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-executor212 D28040 1814 1806 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: 0033:0x401860 Code: 65 74 68 6f 73 74 6e 61 6d 65 00 63 68 6f 77 6e 00 66 77 72 69 74 65 00 66 72 65 61 64 00 67 65 74 65 75 69 64 00 77 61 69 74 <70> 69 64 00 6c 6f 63 61 6c 74 69 6d 65 00 73 74 72 63 68 72 00 66 RSP: 002b:00007ffdbfbcde58 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: 0000000000000004 RBX: 0000000000000000 RCX: 0000000000401860 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007ffdbfbcde70 RBP: 00000000004a6b70 R08: 0000000000000000 R09: 000000000000000f R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000402880 R13: 0000000000402910 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor212:1815 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-executor212 D28472 1815 1803 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: 0033:0x445669 Code: Bad RIP value. RSP: 002b:00007ffdbfbcdf08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: fffffffffffffe00 RBX: 0000000000000003 RCX: 0000000000445669 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00000000004a6b70 R08: 000000000000000f R09: 0000000120080522 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402880 R13: 0000000000402910 R14: 0000000000000000 R15: 0000000000000000 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/1676: #0: ffff8881d0ef40e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 2 locks held by getty/1766: #0: ffff8881ced80090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000049f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1767: #0: ffff8881ced40090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004912e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1768: #0: ffff8881cf2ac090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004852e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1769: #0: ffff8881ced82090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004a32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1770: #0: ffff8881ced84090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004af2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1771: #0: ffff8881ced83090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900004a72e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/1772: #0: ffff8881cf596090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000047d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 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 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+0x28/0x300 arch/x86/kernel/process.c:695