[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.386525][ T25] audit: type=1800 audit(1571064539.455:25): pid=7041 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.422081][ T25] audit: type=1800 audit(1571064539.455:26): pid=7041 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.446172][ T25] audit: type=1800 audit(1571064539.455:27): pid=7041 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 '10.128.1.58' (ECDSA) to the list of known hosts. 2019/10/14 14:49:10 fuzzer started 2019/10/14 14:49:11 dialing manager at 10.128.0.105:43961 2019/10/14 14:49:11 syscalls: 2523 2019/10/14 14:49:11 code coverage: enabled 2019/10/14 14:49:11 comparison tracing: enabled 2019/10/14 14:49:11 extra coverage: extra coverage is not supported by the kernel 2019/10/14 14:49:11 setuid sandbox: enabled 2019/10/14 14:49:11 namespace sandbox: enabled 2019/10/14 14:49:11 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/14 14:49:11 fault injection: enabled 2019/10/14 14:49:11 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/14 14:49:11 net packet injection: enabled 2019/10/14 14:49:11 net device setup: enabled 2019/10/14 14:49:11 concurrency sanitizer: enabled syzkaller login: [ 47.484281][ C0] ================================================================== [ 47.493340][ C0] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 47.501899][ C0] [ 47.504213][ C0] write to 0xffff88812fffcf58 of 8 bytes by task 7203 on cpu 1: [ 47.511828][ C0] free_one_page+0x214/0x840 [ 47.516397][ C0] __free_pages_ok+0x370/0x640 [ 47.521160][ C0] page_frag_free+0xd0/0x100 [ 47.525731][ C0] skb_free_head+0x55/0x80 [ 47.530134][ C0] skb_release_data+0x25d/0x3a0 [ 47.535145][ C0] skb_release_all+0x44/0x60 [ 47.539721][ C0] __kfree_skb+0x1f/0x30 [ 47.543949][ C0] tcp_recvmsg+0xf59/0x1a30 [ 47.548444][ C0] inet_recvmsg+0xbb/0x250 [ 47.552838][ C0] sock_recvmsg+0x92/0xb0 [ 47.557154][ C0] sock_read_iter+0x15f/0x1e0 [ 47.561810][ C0] new_sync_read+0x389/0x4f0 [ 47.566379][ C0] __vfs_read+0xb1/0xc0 [ 47.570509][ C0] vfs_read+0x143/0x2c0 [ 47.574642][ C0] [ 47.576950][ C0] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 0: [ 47.584472][ C0] __zone_watermark_ok+0x106/0x240 [ 47.589563][ C0] get_page_from_freelist+0x629/0x2300 [ 47.595003][ C0] __alloc_pages_nodemask+0x255/0x4d0 [ 47.600364][ C0] page_frag_alloc+0x11e/0x2d0 [ 47.605114][ C0] __napi_alloc_skb+0x172/0x210 [ 47.609953][ C0] page_to_skb+0x8d/0x480 [ 47.614265][ C0] receive_buf+0x17c7/0x30b0 [ 47.618832][ C0] virtnet_poll+0x436/0x7d0 [ 47.623325][ C0] net_rx_action+0x3ae/0xa50 [ 47.627891][ C0] __do_softirq+0x115/0x33f [ 47.632425][ C0] run_ksoftirqd+0x46/0x60 [ 47.636874][ C0] smpboot_thread_fn+0x37d/0x4a0 [ 47.641803][ C0] kthread+0x1d4/0x200 [ 47.645868][ C0] [ 47.648174][ C0] Reported by Kernel Concurrency Sanitizer on: [ 47.654319][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0+ #0 [ 47.661247][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.671277][ C0] ================================================================== [ 47.679316][ C0] Kernel panic - not syncing: panic_on_warn set ... [ 47.685879][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0+ #0 [ 47.692794][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.702831][ C0] Call Trace: [ 47.706118][ C0] dump_stack+0xf5/0x159 [ 47.710353][ C0] panic+0x209/0x639 [ 47.714238][ C0] ? net_rx_action+0x3ae/0xa50 [ 47.718990][ C0] ? vprintk_func+0x8d/0x140 [ 47.723565][ C0] kcsan_report.cold+0xc/0x1b [ 47.728223][ C0] __kcsan_setup_watchpoint+0x3ee/0x510 [ 47.733753][ C0] __tsan_read8+0x2c/0x30 [ 47.738069][ C0] __zone_watermark_ok+0x106/0x240 [ 47.743170][ C0] get_page_from_freelist+0x629/0x2300 [ 47.748626][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 47.754298][ C0] ? __tsan_read8+0x2c/0x30 [ 47.759353][ C0] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 47.765580][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 47.771199][ C0] __alloc_pages_nodemask+0x255/0x4d0 [ 47.776706][ C0] page_frag_alloc+0x11e/0x2d0 [ 47.781449][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 47.787073][ C0] __napi_alloc_skb+0x172/0x210 [ 47.791957][ C0] page_to_skb+0x8d/0x480 [ 47.796293][ C0] receive_buf+0x17c7/0x30b0 [ 47.800879][ C0] ? __tsan_write8+0x32/0x40 [ 47.805473][ C0] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 47.810922][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 47.816531][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 47.822144][ C0] virtnet_poll+0x436/0x7d0 [ 47.827338][ C0] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 47.833561][ C0] net_rx_action+0x3ae/0xa50 [ 47.838148][ C0] __do_softirq+0x115/0x33f [ 47.842635][ C0] ? takeover_tasklets+0x250/0x250 [ 47.847736][ C0] run_ksoftirqd+0x46/0x60 [ 47.852131][ C0] smpboot_thread_fn+0x37d/0x4a0 [ 47.857049][ C0] kthread+0x1d4/0x200 [ 47.861095][ C0] ? constant_test_bit.constprop.0+0x30/0x30 [ 47.867053][ C0] ? kthread_bind+0x50/0x50 [ 47.871578][ C0] ret_from_fork+0x1f/0x30 [ 47.877944][ C0] Kernel Offset: disabled [ 47.882269][ C0] Rebooting in 86400 seconds..