[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.135' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 838.996271] audit: type=1400 audit(1602691088.231:8): avc: denied { execmem } for pid=6497 comm="syz-executor026" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 [ 839.033103] NILFS (loop0): broken superblock, retrying with spare superblock (blocksize = 1024) [ 839.043675] NILFS (loop0): broken superblock, retrying with spare superblock (blocksize = 2048) [ 839.055118] NILFS (loop0): mounting unchecked fs [ 839.067126] NILFS (loop0): recovery complete [ 839.075148] NILFS (loop0): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds [ 986.222755] INFO: task syz-executor026:6497 blocked for more than 140 seconds. [ 986.230373] Not tainted 4.19.150-syzkaller #0 [ 986.235489] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 986.243541] syz-executor026 D28240 6497 6491 0x00000000 [ 986.249220] Call Trace: [ 986.251897] __schedule+0x8e5/0x22e0 [ 986.255696] ? io_schedule_timeout+0x140/0x140 [ 986.260393] schedule+0x8d/0x1b0 [ 986.263926] wb_wait_for_completion+0x175/0x1f0 [ 986.268605] ? block_dump___mark_inode_dirty+0x2b0/0x2b0 [ 986.274157] ? wait_woken+0x320/0x320 [ 986.277972] sync_inodes_sb+0x19d/0xa20 [ 986.281972] ? lock_downgrade+0x750/0x750 [ 986.286236] ? radix_tree_tagged+0x2e/0x70 [ 986.290507] ? __filemap_fdatawrite_range+0x198/0x350 [ 986.296556] ? writeback_inodes_sb_nr+0x30/0x30 [ 986.301263] ? get_nr_dirty_inodes+0x1fc/0x2d0 [ 986.305985] sync_filesystem+0x15c/0x250 [ 986.310081] generic_shutdown_super+0x70/0x370 [ 986.314715] kill_block_super+0x97/0xf0 [ 986.318705] deactivate_locked_super+0x8c/0x100 [ 986.323433] deactivate_super+0x174/0x1a0 [ 986.327593] ? deactivate_locked_super+0x100/0x100 [ 986.332566] ? dput+0x31/0x6a0 [ 986.335854] cleanup_mnt+0x1da/0x300 [ 986.339682] task_work_run+0x141/0x1c0 [ 986.343737] exit_to_usermode_loop+0x269/0x2c0 [ 986.348373] do_syscall_64+0x57c/0x670 [ 986.352268] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 986.357560] RIP: 0033:0x44e0e7 [ 986.360780] Code: Bad RIP value. [ 986.364240] RSP: 002b:00007ffebb447b88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 [ 986.371957] RAX: 0000000000000000 RBX: 00000000000ccd60 RCX: 000000000044e0e7 [ 986.379277] RDX: 0000000000400d27 RSI: 0000000000000002 RDI: 00007ffebb447c30 [ 986.386681] RBP: 0000000000001962 R08: 0000000000000000 R09: 0000000000000009 [ 986.394000] R10: 0000000000000005 R11: 0000000000000206 R12: 00007ffebb448ce0 [ 986.401279] R13: 0000000000b33880 R14: 0000000000000000 R15: 0000000000000000 [ 986.408702] [ 986.408702] Showing all locks held in the system: [ 986.415136] 1 lock held by khungtaskd/1089: [ 986.419508] #0: 00000000cfdb6ce9 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x291 [ 986.428921] 2 locks held by kworker/u4:4/2429: [ 986.433621] #0: 00000000d05bc792 ((wq_completion)"writeback"){+.+.}, at: process_one_work+0x692/0x14e0 [ 986.443262] #1: 0000000050327741 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x6c8/0x14e0 [ 986.454083] 1 lock held by in:imklog/6188: [ 986.458327] #0: 0000000011c897b5 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 [ 986.466327] 2 locks held by syz-executor026/6497: [ 986.471173] #0: 00000000eec867a1 (&type->s_umount_key#59){+.+.}, at: deactivate_super+0x16c/0x1a0 [ 986.480360] #1: 000000002119cf64 (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x180/0xa20 [ 986.489356] [ 986.490980] ============================================= [ 986.490980] [ 986.498048] NMI backtrace for cpu 1 [ 986.501681] CPU: 1 PID: 1089 Comm: khungtaskd Not tainted 4.19.150-syzkaller #0 [ 986.509121] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 986.518456] Call Trace: [ 986.521032] dump_stack+0x22c/0x33e [ 986.524647] nmi_cpu_backtrace.cold+0x18/0x3d [ 986.529188] ? nmi_cpu_backtrace_handler+0x10/0x10 [ 986.534112] nmi_trigger_cpumask_backtrace+0x1a6/0x1eb [ 986.539425] watchdog+0xa62/0x1020 [ 986.542987] ? reset_hung_task_detector+0x30/0x30 [ 986.547839] kthread+0x33f/0x460 [ 986.551190] ? kthread_park+0x180/0x180 [ 986.555168] ret_from_fork+0x24/0x30 [ 986.559010] Sending NMI from CPU 1 to CPUs 0: [ 986.563799] NMI backtrace for cpu 0 [ 986.563806] CPU: 0 PID: 3708 Comm: systemd-journal Not tainted 4.19.150-syzkaller #0 [ 986.563812] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 986.563817] RIP: 0010:lockdep_sys_exit+0x2e/0x50 [ 986.563828] Code: 00 00 00 fc ff df 55 65 48 8b 2c 25 40 ee 01 00 48 8d bd 80 08 00 00 48 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 04 3c 03 7e 1b <8b> 85 80 08 00 00 85 c0 75 02 5d c3 e8 61 60 46 02 85 c0 0f 85 84 [ 986.563833] RSP: 0018:ffff8880944aff18 EFLAGS: 00000046 [ 986.563841] RAX: 0000000000000000 RBX: ffff8880944a0680 RCX: ffffffff8100a851 [ 986.563847] RDX: 1ffff110128941e0 RSI: ffffffff8100a71f RDI: ffff8880944a0f00 [ 986.563852] RBP: ffff8880944a0680 R08: 0000000000000000 R09: 0000000000000000 [ 986.563858] R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000000 [ 986.563863] R13: ffffffff896389f8 R14: 0000000000000000 R15: 0000000000000000 [ 986.563869] FS: 00007f2ec9afc8c0(0000) GS:ffff8880ae200000(0000) knlGS:0000000000000000 [ 986.563874] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 986.563879] CR2: 00007f2ec6ea5000 CR3: 0000000094861000 CR4: 00000000001406f0 [ 986.563885] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 986.563890] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 986.563893] Call Trace: [ 986.563897] do_syscall_64+0x304/0x670 [ 986.563902] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 986.563906] RIP: 0033:0x7f2ec8db8687 [ 986.563917] Code: 00 b8 ff ff ff ff c3 0f 1f 40 00 48 8b 05 09 d8 2b 00 64 c7 00 5f 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 d7 2b 00 f7 d8 64 89 01 48 [ 986.563921] RSP: 002b:00007ffdfe530c38 EFLAGS: 00000293 ORIG_RAX: 0000000000000053 [ 986.563930] RAX: fffffffffffffffe RBX: 00007ffdfe533ca0 RCX: 00007f2ec8db8687 [ 986.563936] RDX: 0000000000000000 RSI: 00000000000001ed RDI: 00005633b2fae8c0 [ 986.563941] RBP: 00007ffdfe530c70 R08: 00005633b1ce13e5 R09: 0000000000000018 [ 986.563947] R10: 0000000000000069 R11: 0000000000000293 R12: 0000000000000000 [ 986.563952] R13: 0000000000000001 R14: 00005633b2fae8c0 R15: 00007ffdfe5312b0 [ 986.565292] Kernel panic - not syncing: hung_task: blocked tasks [ 986.771056] CPU: 1 PID: 1089 Comm: khungtaskd Not tainted 4.19.150-syzkaller #0 [ 986.778482] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 986.787833] Call Trace: [ 986.790408] dump_stack+0x22c/0x33e [ 986.794106] panic+0x2ac/0x565 [ 986.797306] ? __warn_printk+0xf3/0xf3 [ 986.801180] ? nmi_cpu_backtrace_handler+0x10/0x10 [ 986.806103] ? ___preempt_schedule+0x16/0x18 [ 986.810492] ? watchdog+0xa62/0x1020 [ 986.814205] ? nmi_trigger_cpumask_backtrace+0x15e/0x1eb [ 986.819640] watchdog+0xa73/0x1020 [ 986.823179] ? reset_hung_task_detector+0x30/0x30 [ 986.828004] kthread+0x33f/0x460 [ 986.831350] ? kthread_park+0x180/0x180 [ 986.835411] ret_from_fork+0x24/0x30 [ 986.840791] Kernel Offset: disabled [ 986.844414] Rebooting in 86400 seconds..