[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.220' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 717.433610] INFO: task syz-executor028:8544 blocked for more than 140 seconds. [ 717.433621] Not tainted 4.19.163-syzkaller #0 [ 717.433626] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 717.433632] syz-executor028 D28536 8544 8113 0x00000004 [ 717.433653] Call Trace: [ 717.433677] __schedule+0x887/0x2040 [ 717.433698] ? io_schedule_timeout+0x140/0x140 [ 717.433718] ? __down+0x13a/0x2a0 [ 717.433729] schedule+0x8d/0x1b0 [ 717.433744] schedule_timeout+0x92d/0xfe0 [ 717.433757] ? check_preemption_disabled+0x41/0x280 [ 717.433773] ? usleep_range+0x170/0x170 [ 717.433787] ? __down+0x17b/0x2a0 [ 717.433804] ? lock_downgrade+0x720/0x720 [ 717.433819] ? _raw_spin_unlock_irq+0x24/0x80 [ 717.433835] ? __down+0x13a/0x2a0 [ 717.433847] __down+0x183/0x2a0 [ 717.433863] ? ww_mutex_lock+0x180/0x180 [ 717.433882] ? do_raw_spin_lock+0xcb/0x220 [ 717.433896] down+0x57/0x80 [ 717.433910] console_lock+0x25/0x80 [ 717.433923] do_fb_ioctl+0x33e/0xb50 [ 717.433939] ? register_framebuffer+0x9e0/0x9e0 [ 717.433951] ? lock_downgrade+0x720/0x720 [ 717.433969] ? page_remove_rmap.part.0+0x2f/0x2c0 [ 717.433985] ? do_raw_spin_unlock+0x171/0x230 [ 717.433998] ? wp_page_copy+0x1203/0x2c40 [ 717.434018] ? clear_subpage.constprop.0+0x100/0x100 [ 717.434047] ? mark_held_locks+0xf0/0xf0 [ 717.434063] ? __handle_mm_fault+0xf34/0x41c0 [ 717.434078] fb_ioctl+0xdd/0x130 [ 717.434090] ? do_fb_ioctl+0xb50/0xb50 [ 717.434103] do_vfs_ioctl+0xcdb/0x12e0 [ 717.434119] ? ioctl_preallocate+0x200/0x200 [ 717.434132] ? __do_page_fault+0x6d1/0xd60 [ 717.434148] ? lock_downgrade+0x720/0x720 [ 717.434166] ? up_read+0x17/0x110 [ 717.434178] ? __do_page_fault+0x180/0xd60 [ 717.434195] ksys_ioctl+0x9b/0xc0 [ 717.434209] __x64_sys_ioctl+0x6f/0xb0 [ 717.434221] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 717.434234] do_syscall_64+0xf9/0x620 [ 717.434249] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 717.434259] RIP: 0033:0x445189 [ 717.434280] Code: Bad RIP value. [ 717.434287] RSP: 002b:00007ffca2fb0678 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 717.434299] RAX: ffffffffffffffda RBX: 0000000020000080 RCX: 0000000000445189 [ 717.434307] RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000003 [ 717.434315] RBP: 000000000008baa0 R08: 00000000004002e0 R09: 00000000004002e0 [ 717.434322] R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000402350 [ 717.434329] R13: 00000000004023e0 R14: 0000000000000000 R15: 0000000000000000 [ 717.434347] [ 717.434347] Showing all locks held in the system: [ 717.434358] 1 lock held by khungtaskd/1566: [ 717.434362] #0: 000000005dfd84a0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 [ 717.434420] 1 lock held by in:imklog/7785: [ 717.434424] #0: 00000000d24e1f0a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 [ 717.434450] 2 locks held by agetty/7765: [ 717.434454] #0: 0000000044ab7ebb (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 [ 717.434478] #1: 00000000eff0ff06 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x217/0x1950 [ 717.434505] 7 locks held by kworker/u4:5/8057: [ 717.434509] [ 717.434514] ============================================= [ 717.434514] [ 717.434520] NMI backtrace for cpu 1 [ 717.434532] CPU: 1 PID: 1566 Comm: khungtaskd Not tainted 4.19.163-syzkaller #0 [ 717.434539] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 717.434543] Call Trace: [ 717.434563] dump_stack+0x1fc/0x2fe [ 717.434581] nmi_cpu_backtrace.cold+0x63/0xa2 [ 717.434597] ? lapic_can_unplug_cpu.cold+0x39/0x39 [ 717.434612] nmi_trigger_cpumask_backtrace+0x1a6/0x1eb [ 717.434628] watchdog+0x991/0xe60 [ 717.434646] ? reset_hung_task_detector+0x30/0x30 [ 717.434660] kthread+0x33f/0x460 [ 717.434671] ? kthread_park+0x180/0x180 [ 717.434684] ret_from_fork+0x24/0x30 [ 717.434705] Sending NMI from CPU 1 to CPUs 0: [ 717.435272] NMI backtrace for cpu 0 [ 717.435277] CPU: 0 PID: 8057 Comm: kworker/u4:5 Not tainted 4.19.163-syzkaller #0 [ 717.435283] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 717.435286] Workqueue: events_unbound flush_to_ldisc [ 717.435292] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 [ 717.435301] Code: 48 c7 c7 80 00 6e 88 4c 89 25 cc 39 bf 0b 41 bc f4 ff ff ff e8 a0 f9 ea ff 48 c7 05 b6 39 bf 0b 00 00 00 00 e9 39 ec ff ff 90 <48> 8b 34 24 65 48 8b 04 25 80 df 01 00 65 8b 15 ec 0e 9d 7e 81 e2 [ 717.435305] RSP: 0018:ffff88808f8274c8 EFLAGS: 00000216 [ 717.435311] RAX: 0000000000000000 RBX: 0000000000000050 RCX: ffffffff83a868c4 [ 717.435316] RDX: 0000000000000044 RSI: ffff88809267e500 RDI: 0000000000000004 [ 717.435320] RBP: 0000000000000044 R08: 0000000000000010 R09: 0000000000000050 [ 717.435324] R10: 0000000000000004 R11: 0000000000000000 R12: ffff8880000a0044 [ 717.435329] R13: ffff8880000a0000 R14: 0000000000000000 R15: 00000000ea302b3e [ 717.435333] FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 [ 717.435337] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 717.435342] CR2: 00000000006cf090 CR3: 00000000a477f000 CR4: 00000000001406f0 [ 717.435346] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 717.435350] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 717.435353] Call Trace: [ 717.435356] vga16fb_fillrect+0x9c0/0x1940 [ 717.435358] bit_clear+0x382/0x4d0 [ 717.435361] ? bit_bmove+0x210/0x210 [ 717.435364] fbcon_clear+0x5d6/0x690 [ 717.435367] ? bit_bmove+0x210/0x210 [ 717.435370] fbcon_scroll+0x42e/0x3440 [ 717.435373] con_scroll+0x5f8/0x720 [ 717.435376] ? __atomic_notifier_call_chain+0xc5/0x180 [ 717.435379] lf+0x262/0x2b0 [ 717.435382] ? con_scroll+0x720/0x720 [ 717.435398] ? __atomic_notifier_call_chain+0xec/0x180 [ 717.435401] do_con_write+0x133e/0x1d90 [ 717.435404] ? do_con_trol+0x5970/0x5970 [ 717.435406] ? do_con_trol+0x5970/0x5970 [ 717.435409] con_put_char+0x96/0xe0 [ 717.435412] ? do_con_write+0x1d90/0x1d90 [ 717.435415] ? con_put_char+0x9e/0xe0 [ 717.435418] ? do_con_write+0x1d90/0x1d90 [ 717.435421] ? do_con_write+0x1d90/0x1d90 [ 717.435423] tty_put_char+0xb7/0x150 [ 717.435426] ? dev_match_devt+0x90/0x90 [ 717.435429] ? do_con_write+0x1d90/0x1d90 [ 717.435432] ? tty_put_char+0xbf/0x150 [ 717.435435] ? dev_match_devt+0x90/0x90 [ 717.435438] do_output_char+0x155/0x850 [ 717.435441] __process_echoes+0x38e/0x9f0 [ 717.435444] n_tty_receive_buf_common+0xc0c/0x2a90 [ 717.435447] tty_ldisc_receive_buf+0xa9/0x190 [ 717.435450] ? n_tty_receive_buf_common+0x2a90/0x2a90 [ 717.435454] tty_port_default_receive_buf+0x78/0xa0 [ 717.435456] flush_to_ldisc+0x21f/0x390 [ 717.435459] process_one_work+0x864/0x1570 [ 717.435463] ? pwq_dec_nr_in_flight+0x2d0/0x2d0 [ 717.435465] worker_thread+0x64c/0x1130 [ 717.435469] ? __kthread_parkme+0x133/0x1e0 [ 717.435472] ? process_one_work+0x1570/0x1570 [ 717.435474] kthread+0x33f/0x460 [ 717.435477] ? kthread_park+0x180/0x180 [ 717.435480] ret_from_fork+0x24/0x30 [ 717.435721] Kernel panic - not syncing: hung_task: blocked tasks [ 717.435732] CPU: 1 PID: 1566 Comm: khungtaskd Not tainted 4.19.163-syzkaller #0 [ 717.435737] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 717.435740] Call Trace: [ 717.435750] dump_stack+0x1fc/0x2fe [ 717.435764] panic+0x26a/0x50e [ 717.435779] ? __warn_printk+0xf3/0xf3 [ 717.435791] ? _raw_spin_unlock_irqrestore+0x79/0xe0 [ 717.435804] ? cpumask_next+0x3c/0x40 [ 717.435818] ? printk_safe_flush+0xd6/0x120 [ 717.435830] ? watchdog+0x991/0xe60 [ 717.435844] ? nmi_trigger_cpumask_backtrace+0x15e/0x1eb [ 717.435857] watchdog+0x9a2/0xe60 [ 717.435872] ? reset_hung_task_detector+0x30/0x30 [ 717.435883] kthread+0x33f/0x460 [ 717.435894] ? kthread_park+0x180/0x180 [ 717.435907] ret_from_fork+0x24/0x30 [ 717.436733] Kernel Offset: disabled