[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.462190][ T25] audit: type=1800 audit(1570845922.144:25): pid=7113 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.481951][ T25] audit: type=1800 audit(1570845922.144:26): pid=7113 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.503497][ T25] audit: type=1800 audit(1570845922.144:27): pid=7113 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 '10.128.0.42' (ECDSA) to the list of known hosts. 2019/10/12 02:05:29 fuzzer started 2019/10/12 02:05:31 dialing manager at 10.128.0.105:43913 2019/10/12 02:05:31 syscalls: 2523 2019/10/12 02:05:31 code coverage: enabled 2019/10/12 02:05:31 comparison tracing: enabled 2019/10/12 02:05:31 extra coverage: extra coverage is not supported by the kernel 2019/10/12 02:05:31 setuid sandbox: enabled 2019/10/12 02:05:31 namespace sandbox: enabled 2019/10/12 02:05:31 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/12 02:05:31 fault injection: enabled 2019/10/12 02:05:31 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/12 02:05:31 net packet injection: enabled 2019/10/12 02:05:31 net device setup: enabled 2019/10/12 02:05:31 concurrency sanitizer: enabled syzkaller login: [ 45.294680][ C1] ================================================================== [ 45.302910][ C1] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 45.310422][ C1] [ 45.312782][ C1] write to 0xffff88812fffcf58 of 8 bytes by task 7261 on cpu 0: [ 45.320388][ C1] free_one_page+0x214/0x840 [ 45.325000][ C1] __free_pages_ok+0x370/0x640 [ 45.329740][ C1] free_compound_page+0x3d/0x50 [ 45.334566][ C1] __put_compound_page+0x4e/0x70 [ 45.339476][ C1] __put_page+0x54/0xd0 [ 45.343607][ C1] skb_release_data+0x1ba/0x3a0 [ 45.348429][ C1] skb_release_all+0x44/0x60 [ 45.352994][ C1] __kfree_skb+0x1f/0x30 [ 45.357236][ C1] tcp_recvmsg+0xf59/0x1a30 [ 45.361718][ C1] inet_recvmsg+0xbb/0x250 [ 45.366110][ C1] sock_recvmsg+0x92/0xb0 [ 45.370515][ C1] sock_read_iter+0x15f/0x1e0 [ 45.375181][ C1] new_sync_read+0x389/0x4f0 [ 45.379746][ C1] __vfs_read+0xb1/0xc0 [ 45.383869][ C1] [ 45.386180][ C1] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 1: [ 45.393703][ C1] __zone_watermark_ok+0x106/0x240 [ 45.398837][ C1] get_page_from_freelist+0x629/0x2300 [ 45.404283][ C1] __alloc_pages_nodemask+0x255/0x4d0 [ 45.409629][ C1] alloc_pages_current+0xd1/0x170 [ 45.414630][ C1] skb_page_frag_refill+0x16f/0x260 [ 45.419803][ C1] try_fill_recv+0x51f/0xdc0 [ 45.424369][ C1] virtnet_poll+0x64c/0x7d0 [ 45.428847][ C1] net_rx_action+0x3ae/0xa50 [ 45.433457][ C1] __do_softirq+0x115/0x33f [ 45.437958][ C1] run_ksoftirqd+0x46/0x60 [ 45.442348][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 45.447258][ C1] kthread+0x1d4/0x200 [ 45.451304][ C1] ret_from_fork+0x1f/0x30 [ 45.455714][ C1] [ 45.458041][ C1] Reported by Kernel Concurrency Sanitizer on: [ 45.464175][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0+ #0 [ 45.471167][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.481326][ C1] ================================================================== [ 45.489472][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 45.496050][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0+ #0 [ 45.503043][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.513090][ C1] Call Trace: [ 45.516362][ C1] dump_stack+0xf5/0x159 [ 45.520597][ C1] panic+0x209/0x639 [ 45.524470][ C1] ? __do_softirq+0x115/0x33f [ 45.529147][ C1] ? vprintk_func+0x8d/0x140 [ 45.533732][ C1] kcsan_report.cold+0xc/0x1b [ 45.538389][ C1] __kcsan_setup_watchpoint+0x3ee/0x510 [ 45.543912][ C1] __tsan_read8+0x2c/0x30 [ 45.548222][ C1] __zone_watermark_ok+0x106/0x240 [ 45.553313][ C1] get_page_from_freelist+0x629/0x2300 [ 45.558754][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 45.564983][ C1] ? __kcsan_setup_watchpoint+0x96/0x510 [ 45.570592][ C1] ? __tsan_read8+0x2c/0x30 [ 45.575074][ C1] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 45.581288][ C1] ? __kcsan_setup_watchpoint+0x96/0x510 [ 45.586908][ C1] __alloc_pages_nodemask+0x255/0x4d0 [ 45.592263][ C1] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 45.598479][ C1] alloc_pages_current+0xd1/0x170 [ 45.603489][ C1] skb_page_frag_refill+0x16f/0x260 [ 45.608666][ C1] try_fill_recv+0x51f/0xdc0 [ 45.613238][ C1] ? __kcsan_setup_watchpoint+0x96/0x510 [ 45.618854][ C1] virtnet_poll+0x64c/0x7d0 [ 45.623336][ C1] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 45.629554][ C1] net_rx_action+0x3ae/0xa50 [ 45.634131][ C1] __do_softirq+0x115/0x33f [ 45.638616][ C1] ? takeover_tasklets+0x250/0x250 [ 45.643709][ C1] run_ksoftirqd+0x46/0x60 [ 45.648115][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 45.653085][ C1] kthread+0x1d4/0x200 [ 45.657143][ C1] ? constant_test_bit.constprop.0+0x30/0x30 [ 45.663109][ C1] ? kthread_bind+0x50/0x50 [ 45.667692][ C1] ret_from_fork+0x1f/0x30 [ 45.673459][ C1] Kernel Offset: disabled [ 45.677779][ C1] Rebooting in 86400 seconds..