[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.098320][ T25] audit: type=1800 audit(1572437286.955:25): pid=7027 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.143160][ T25] audit: type=1800 audit(1572437286.965:26): pid=7027 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.182601][ T25] audit: type=1800 audit(1572437286.965:27): pid=7027 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2469 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.55' (ECDSA) to the list of known hosts. 2019/10/30 12:08:14 fuzzer started 2019/10/30 12:08:15 dialing manager at 10.128.0.105:40771 2019/10/30 12:08:15 syscalls: 2540 2019/10/30 12:08:15 code coverage: enabled 2019/10/30 12:08:15 comparison tracing: enabled 2019/10/30 12:08:15 extra coverage: extra coverage is not supported by the kernel 2019/10/30 12:08:15 setuid sandbox: enabled 2019/10/30 12:08:15 namespace sandbox: enabled 2019/10/30 12:08:15 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/30 12:08:15 fault injection: enabled 2019/10/30 12:08:15 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/30 12:08:15 net packet injection: enabled 2019/10/30 12:08:15 net device setup: enabled 2019/10/30 12:08:15 concurrency sanitizer: enabled syzkaller login: [ 51.004290][ T7191] KCSAN: could not find function: 'poll_schedule_timeout' [ 59.579314][ T2685] ================================================================== [ 59.587435][ T2685] BUG: KCSAN: data-race in __blk_queue_split / bio_endio [ 59.594460][ T2685] [ 59.596783][ T2685] read to 0xffff888124998614 of 2 bytes by interrupt on cpu 1: [ 59.604339][ T2685] bio_endio+0x3e/0x4f0 [ 59.608497][ T2685] blk_update_request+0x427/0x7b0 [ 59.613521][ T2685] scsi_end_request+0x6b/0x3e0 [ 59.618273][ T2685] scsi_io_completion+0x11d/0xc80 [ 59.623284][ T2685] scsi_finish_command+0x280/0x380 [ 59.628384][ T2685] scsi_softirq_done+0x259/0x280 [ 59.633314][ T2685] blk_done_softirq+0x1eb/0x250 [ 59.638155][ T2685] __do_softirq+0x115/0x33f [ 59.642644][ T2685] irq_exit+0xbb/0xe0 [ 59.646612][ T2685] do_IRQ+0xa6/0x180 [ 59.650494][ T2685] ret_from_intr+0x0/0x19 [ 59.654810][ T2685] __kcsan_setup_watchpoint+0x81/0x4a0 [ 59.660254][ T2685] __tsan_write1+0x32/0x40 [ 59.664659][ T2685] kallsyms_expand_symbol.constprop.0+0xe8/0x160 [ 59.670971][ T2685] [ 59.673297][ T2685] write to 0xffff888124998614 of 2 bytes by task 2685 on cpu 0: [ 59.681185][ T2685] __blk_queue_split+0x726/0xb40 [ 59.686123][ T2685] blk_mq_make_request+0x104/0xf60 [ 59.691227][ T2685] generic_make_request+0x196/0x740 [ 59.696415][ T2685] submit_bio+0x96/0x3c0 [ 59.700648][ T2685] ext4_io_submit+0xdf/0x110 [ 59.705224][ T2685] ext4_writepages+0xea9/0x2300 [ 59.710068][ T2685] do_writepages+0x6b/0x170 [ 59.714562][ T2685] __writeback_single_inode+0xaf/0x8e0 [ 59.720009][ T2685] writeback_sb_inodes+0x4ba/0xa50 [ 59.725109][ T2685] __writeback_inodes_wb+0xe8/0x1b0 [ 59.730290][ T2685] wb_writeback+0x557/0x6a0 [ 59.734779][ T2685] wb_workfn+0x7bb/0x970 [ 59.739007][ T2685] process_one_work+0x3d4/0x890 [ 59.743836][ T2685] [ 59.746161][ T2685] Reported by Kernel Concurrency Sanitizer on: [ 59.752305][ T2685] CPU: 0 PID: 2685 Comm: kworker/u4:4 Not tainted 5.4.0-rc3+ #0 [ 59.759914][ T2685] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 59.769961][ T2685] Workqueue: writeback wb_workfn (flush-8:0) [ 59.775934][ T2685] ================================================================== [ 59.783982][ T2685] Kernel panic - not syncing: panic_on_warn set ... [ 59.790562][ T2685] CPU: 0 PID: 2685 Comm: kworker/u4:4 Not tainted 5.4.0-rc3+ #0 [ 59.798174][ T2685] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 59.808222][ T2685] Workqueue: writeback wb_workfn (flush-8:0) [ 59.814194][ T2685] Call Trace: [ 59.817478][ T2685] dump_stack+0xf5/0x159 [ 59.821711][ T2685] panic+0x210/0x640 [ 59.825608][ T2685] ? writeback_sb_inodes+0x4ba/0xa50 [ 59.830882][ T2685] ? vprintk_func+0x8d/0x140 [ 59.835474][ T2685] kcsan_report.cold+0xc/0x10 [ 59.840149][ T2685] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 59.845692][ T2685] __tsan_write2+0x32/0x40 [ 59.850105][ T2685] __blk_queue_split+0x726/0xb40 [ 59.855048][ T2685] blk_mq_make_request+0x104/0xf60 [ 59.860153][ T2685] ? blk_queue_enter+0x53b/0x610 [ 59.865086][ T2685] generic_make_request+0x196/0x740 [ 59.870280][ T2685] submit_bio+0x96/0x3c0 [ 59.874615][ T2685] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 59.880256][ T2685] ext4_io_submit+0xdf/0x110 [ 59.884841][ T2685] ext4_writepages+0xea9/0x2300 [ 59.889692][ T2685] ? __ext4_get_inode_loc+0x272/0x960 [ 59.895068][ T2685] ? ext4_mark_inode_dirty+0x420/0x420 [ 59.900518][ T2685] do_writepages+0x6b/0x170 [ 59.905011][ T2685] ? do_writepages+0x6b/0x170 [ 59.909677][ T2685] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 59.915305][ T2685] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 59.920929][ T2685] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 59.926546][ T2685] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 59.932175][ T2685] __writeback_single_inode+0xaf/0x8e0 [ 59.937623][ T2685] ? __tsan_read8+0x2c/0x30 [ 59.942118][ T2685] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 59.947746][ T2685] writeback_sb_inodes+0x4ba/0xa50 [ 59.952858][ T2685] __writeback_inodes_wb+0xe8/0x1b0 [ 59.958046][ T2685] wb_writeback+0x557/0x6a0 [ 59.962566][ T2685] wb_workfn+0x7bb/0x970 [ 59.966818][ T2685] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 59.972459][ T2685] process_one_work+0x3d4/0x890 [ 59.977309][ T2685] worker_thread+0xa0/0x800 [ 59.981813][ T2685] kthread+0x1d4/0x200 [ 59.985879][ T2685] ? rescuer_thread+0x6a0/0x6a0 [ 59.990721][ T2685] ? kthread_stop+0x2d0/0x2d0 [ 59.995394][ T2685] ret_from_fork+0x1f/0x30 [ 60.027591][ T2685] Kernel Offset: disabled [ 60.031924][ T2685] Rebooting in 86400 seconds..