[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
[ 51.587238][ T27] kauditd_printk_skb: 7 callbacks suppressed
[ 51.587256][ T27] audit: type=1800 audit(1580541036.057:29): pid=7927 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2465 res=0
[ 51.613560][ T27] audit: type=1800 audit(1580541036.057:30): pid=7927 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2456 res=0
Debian GNU/Linux 7 syzkaller ttyS0
Warning: Permanently added '10.128.0.31' (ECDSA) to the list of known hosts.
2020/02/01 07:10:46 fuzzer started
2020/02/01 07:10:49 dialing manager at 10.128.0.105:34981
2020/02/01 07:10:49 syscalls: 2904
2020/02/01 07:10:49 code coverage: enabled
2020/02/01 07:10:49 comparison tracing: enabled
2020/02/01 07:10:49 extra coverage: enabled
2020/02/01 07:10:49 setuid sandbox: enabled
2020/02/01 07:10:49 namespace sandbox: enabled
2020/02/01 07:10:49 Android sandbox: /sys/fs/selinux/policy does not exist
2020/02/01 07:10:49 fault injection: enabled
2020/02/01 07:10:49 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled
2020/02/01 07:10:49 net packet injection: enabled
2020/02/01 07:10:49 net device setup: enabled
2020/02/01 07:10:49 concurrency sanitizer: enabled
2020/02/01 07:10:49 devlink PCI setup: PCI device 0000:00:10.0 is not available
syzkaller login: [ 67.531862][ C0] ==================================================================
[ 67.540122][ C0] BUG: KCSAN: data-race in __hrtimer_run_queues / hrtimer_active
[ 67.547839][ C0]
[ 67.550164][ C0] read to 0xffff88812c01fbd8 of 8 bytes by interrupt on cpu 1:
[ 67.557924][ C0] hrtimer_active+0x84/0x1a0
[ 67.562524][ C0] task_tick_fair+0x4c/0x910
[ 67.567120][ C0] scheduler_tick+0x5f/0xf0
[ 67.571645][ C0] update_process_times+0x5a/0x80
[ 67.576779][ C0] tick_sched_handle+0x75/0x100
[ 67.581668][ C0] tick_sched_timer+0x58/0xe0
[ 67.586353][ C0] __hrtimer_run_queues+0x274/0x5f0
[ 67.591556][ C0] hrtimer_interrupt+0x22a/0x480
[ 67.596498][ C0] smp_apic_timer_interrupt+0xdc/0x280
[ 67.602078][ C0] apic_timer_interrupt+0xf/0x20
[ 67.607024][ C0] __tsan_read1+0x86/0x100
[ 67.611451][ C0] kallsyms_expand_symbol.constprop.0+0x70/0x160
[ 67.617787][ C0] kallsyms_lookup_name+0x7f/0x120
[ 67.622904][ C0] debugfs_write+0x14b/0x2d0
[ 67.627517][ C0] full_proxy_write+0xbd/0x100
[ 67.632290][ C0] __vfs_write+0x67/0xc0
[ 67.636538][ C0] vfs_write+0x18a/0x390
[ 67.641041][ C0] ksys_write+0xd5/0x1b0
[ 67.645297][ C0] __x64_sys_write+0x4c/0x60
[ 67.649959][ C0] do_syscall_64+0xcc/0x3a0
[ 67.654470][ C0] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 67.660356][ C0]
[ 67.662685][ C0] write to 0xffff88812c01fbd8 of 8 bytes by interrupt on cpu 0:
[ 67.670372][ C0] __hrtimer_run_queues+0x1e8/0x5f0
[ 67.675581][ C0] hrtimer_interrupt+0x22a/0x480
[ 67.680524][ C0] smp_apic_timer_interrupt+0xdc/0x280
[ 67.686096][ C0] apic_timer_interrupt+0xf/0x20
[ 67.691031][ C0] __read_once_size+0x47/0xe0
[ 67.695711][ C0] __test_set_page_writeback+0x41/0x7d0
[ 67.701259][ C0] ext4_bio_write_page+0x157/0xb4e
[ 67.706379][ C0] mpage_submit_page+0xe4/0x1a0
[ 67.711234][ C0] mpage_map_and_submit_buffers+0x3c4/0x6c0
[ 67.717130][ C0] ext4_writepages+0x1449/0x2500
[ 67.722080][ C0] do_writepages+0x6b/0x170
[ 67.726599][ C0] __writeback_single_inode+0xaf/0x8e0
[ 67.732157][ C0] writeback_sb_inodes+0x4ba/0xa50
[ 67.737414][ C0] __writeback_inodes_wb+0xe8/0x1b0
[ 67.742618][ C0] wb_writeback+0x557/0x6a0
[ 67.747123][ C0] wb_workfn+0x696/0x970
[ 67.751385][ C0] process_one_work+0x3d4/0x890
[ 67.756246][ C0] worker_thread+0xa0/0x800
[ 67.760892][ C0] kthread+0x1d4/0x200
[ 67.764966][ C0] ret_from_fork+0x1f/0x30
[ 67.769563][ C0]
[ 67.771888][ C0] Reported by Kernel Concurrency Sanitizer on:
[ 67.778045][ C0] CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.5.0-rc1-syzkaller #0
[ 67.786283][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 67.796347][ C0] Workqueue: writeback wb_workfn (flush-8:0)
[ 67.802329][ C0] ==================================================================
[ 67.810678][ C0] Kernel panic - not syncing: panic_on_warn set ...
[ 67.817266][ C0] CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.5.0-rc1-syzkaller #0
[ 67.825716][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 67.835921][ C0] Workqueue: writeback wb_workfn (flush-8:0)
[ 67.841925][ C0] Call Trace:
[ 67.845199][ C0]
[ 67.848060][ C0] dump_stack+0x11d/0x181
[ 67.852569][ C0] panic+0x210/0x640
[ 67.856990][ C0] ? vprintk_func+0x8d/0x140
[ 67.861678][ C0] kcsan_report.cold+0xc/0xd
[ 67.866304][ C0] kcsan_setup_watchpoint+0x3fe/0x460
[ 67.871685][ C0] __tsan_unaligned_write8+0xc7/0x110
[ 67.877073][ C0] __hrtimer_run_queues+0x1e8/0x5f0
[ 67.882282][ C0] ? ktime_get_update_offsets_now+0x28f/0x2f0
[ 67.888343][ C0] hrtimer_interrupt+0x22a/0x480
[ 67.893297][ C0] ? sched_clock+0x13/0x20
[ 67.897734][ C0] smp_apic_timer_interrupt+0xdc/0x280
[ 67.903310][ C0] apic_timer_interrupt+0xf/0x20
[ 67.908340][ C0]
[ 67.911429][ C0] RIP: 0010:__read_once_size+0x47/0xe0
[ 67.916902][ C0] Code: 3e 05 85 e8 2b 53 e9 ff 83 fb 04 74 1e 83 fb 08 75 32 e8 5c 51 e9 ff 49 8b 04 24 49 89 45 00 e8 4f 51 e9 ff 5b 41 5c 41 5d 5d e8 43 51 e9 ff 41 8b 04 24 41 89 45 00 e8 36 51 e9 ff 5b 41 5c
[ 67.936512][ C0] RSP: 0018:ffffc90000d1f538 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
[ 67.944936][ C0] RAX: ffff88812b7f4080 RBX: ffffea00048c78c0 RCX: ffffffff815bb4e5
[ 67.952913][ C0] RDX: 0000000000000000 RSI: ffffffff815bb501 RDI: 0000000000000005
[ 67.961009][ C0] RBP: ffffc90000d1f578 R08: ffff88812b7f4080 R09: 0000c90000d1f688
[ 67.969090][ C0] R10: 000088812b7f43f8 R11: 0000c90000d1f68f R12: ffffea00048c78c0
[ 67.977328][ C0] R13: ffffea00048c78c8 R14: 0000000000000000 R15: ffffea00048c78c8
[ 67.985317][ C0] ? __read_once_size+0x25/0xe0
[ 67.990184][ C0] ? __read_once_size+0x41/0xe0
[ 67.995054][ C0] ? page_mapping+0x46/0x2a0
[ 67.999689][ C0] __test_set_page_writeback+0x41/0x7d0
[ 68.005246][ C0] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20
[ 68.011501][ C0] ? __this_cpu_preempt_check+0x45/0x140
[ 68.017149][ C0] ? __mod_memcg_state+0x9a/0x120
[ 68.022194][ C0] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20
[ 68.028825][ C0] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[ 68.035103][ C0] ext4_bio_write_page+0x157/0xb4e
[ 68.040239][ C0] mpage_submit_page+0xe4/0x1a0
[ 68.045096][ C0] mpage_map_and_submit_buffers+0x3c4/0x6c0
[ 68.051791][ C0] ? audit_tag_tree+0x96f/0xca0
[ 68.056711][ C0] ext4_writepages+0x1449/0x2500
[ 68.060228][ T8094] KCSAN: could not find function: 'poll_schedule_timeout'
[ 68.061704][ C0] ? delay_loop+0x20/0x30
[ 68.073271][ C0] ? __ext4_get_inode_loc+0x272/0x960
[ 68.078658][ C0] ? ext4_mark_inode_dirty+0x420/0x420
[ 68.084222][ C0] do_writepages+0x6b/0x170
[ 68.088740][ C0] ? do_writepages+0x6b/0x170
[ 68.093442][ C0] ? ext4_write_inode+0xa9/0x330
[ 68.098378][ C0] ? __sanitizer_cov_trace_switch+0x49/0x80
[ 68.104279][ C0] ? __sanitizer_cov_trace_switch+0x49/0x80
[ 68.110399][ C0] __writeback_single_inode+0xaf/0x8e0
[ 68.115882][ C0] ? _raw_spin_unlock+0x4b/0x60
[ 68.120834][ C0] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20
[ 68.127114][ C0] ? __sanitizer_cov_trace_switch+0x49/0x80
[ 68.133013][ C0] writeback_sb_inodes+0x4ba/0xa50
[ 68.138281][ C0] __writeback_inodes_wb+0xe8/0x1b0
[ 68.143615][ C0] wb_writeback+0x557/0x6a0
[ 68.148131][ C0] wb_workfn+0x696/0x970
[ 68.152393][ C0] process_one_work+0x3d4/0x890
[ 68.157268][ C0] worker_thread+0xa0/0x800
[ 68.161787][ C0] kthread+0x1d4/0x200
[ 68.165984][ C0] ? rescuer_thread+0x6a0/0x6a0
[ 68.170830][ C0] ? kthread_unpark+0xe0/0xe0
[ 68.175522][ C0] ret_from_fork+0x1f/0x30
[ 68.204840][ C0] Kernel Offset: disabled
[ 68.209277][ C0] Rebooting in 86400 seconds..