INFO: task syz-executor.2:9155 blocked for more than 143 seconds. Not tainted 5.9.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:28816 pid: 9155 ppid: 354 flags:0x80004006 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x889/0x1f70 kernel/sched/core.c:4527 schedule+0xcd/0x2b0 kernel/sched/core.c:4602 wdm_flush+0x2e9/0x3c0 drivers/usb/class/cdc-wdm.c:590 filp_close+0xb4/0x170 fs/open.c:1276 close_files fs/file.c:401 [inline] put_files_struct fs/file.c:429 [inline] put_files_struct+0x1d0/0x350 fs/file.c:426 exit_files+0x7e/0xa0 fs/file.c:458 do_exit+0xb75/0x2890 kernel/exit.c:801 do_group_exit+0x125/0x310 kernel/exit.c:903 get_signal+0x42d/0x1f10 kernel/signal.c:2757 arch_do_signal+0x88/0x1a00 arch/x86/kernel/signal.c:811 exit_to_user_mode_loop kernel/entry/common.c:135 [inline] exit_to_user_mode_prepare+0xf9/0x150 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x36/0x260 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45ba81 Code: Bad RIP value. RSP: 002b:00007ffcece93220 EFLAGS: 00000293 ORIG_RAX: 0000000000000023 RAX: 0000000000000000 RBX: 0000000000051a34 RCX: 000000000045ba81 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffcece93230 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffcece93330 R11: 0000000000000293 R12: 000000000118cf40 R13: 000000000118d940 R14: ffffffffffffffff R15: 000000000118cf4c Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: ffffffff87313620 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5825 1 lock held by in:imklog/249: #0: ffff8881c7e52ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 2 locks held by agetty/244: #0: ffff8881d3eae098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc90000a162e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 5.9.0-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+0xf6/0x16e lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x74/0xb6 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1da/0x1f4 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd6a/0xfd0 kernel/hung_task.c:295 kthread+0x392/0x470 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 119 Comm: systemd-journal Not tainted 5.9.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0033:0x7f996aeda770 Code: 00 48 8d 35 7a 15 01 00 48 8d 3d c9 11 01 00 ba 69 09 00 00 e8 d1 58 f1 ff e8 cc 57 f1 ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 <41> 57 41 56 41 55 41 54 55 53 48 83 ec 38 64 48 8b 04 25 28 00 00 RSP: 002b:00007ffecf201b28 EFLAGS: 00000202 RAX: 00000000fa9bf6df RBX: 000055f96a083420 RCX: 0441f0e2fa9bf6df RDX: 000000000000001b RSI: 000055f96a083420 RDI: 000055f96a07ae80 RBP: 000000000000001b R08: 00007ffecf201b88 R09: 00007ffecf201b80 R10: 00007f996af04ee8 R11: 00007ffecf201b80 R12: 000055f96a07ae80 R13: 0000000000000000 R14: 00007ffecf201cd8 R15: 0441f0e2fa9bf6df FS: 00007f996b1e98c0 GS: 0000000000000000