[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.263852][ T23] audit: type=1800 audit(1570920543.499:25): pid=7082 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.303007][ T23] audit: type=1800 audit(1570920543.499:26): pid=7082 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.337596][ T23] audit: type=1800 audit(1570920543.509:27): pid=7082 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 '10.128.0.245' (ECDSA) to the list of known hosts. 2019/10/12 22:49:11 fuzzer started 2019/10/12 22:49:13 dialing manager at 10.128.0.105:43913 2019/10/12 22:49:13 syscalls: 2523 2019/10/12 22:49:13 code coverage: enabled 2019/10/12 22:49:13 comparison tracing: enabled 2019/10/12 22:49:13 extra coverage: extra coverage is not supported by the kernel 2019/10/12 22:49:13 setuid sandbox: enabled 2019/10/12 22:49:13 namespace sandbox: enabled 2019/10/12 22:49:13 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/12 22:49:13 fault injection: enabled 2019/10/12 22:49:13 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/12 22:49:13 net packet injection: enabled 2019/10/12 22:49:13 net device setup: enabled 2019/10/12 22:49:13 concurrency sanitizer: enabled syzkaller login: [ 44.638535][ C0] ================================================================== [ 44.646665][ C0] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 44.654178][ C0] [ 44.656486][ C0] write to 0xffff88812fffcf58 of 8 bytes by task 7233 on cpu 1: [ 44.664147][ C0] free_one_page+0x214/0x840 [ 44.668712][ C0] __free_pages_ok+0x370/0x640 [ 44.673452][ C0] page_frag_free+0xd0/0x100 [ 44.678017][ C0] skb_free_head+0x55/0x80 [ 44.682406][ C0] skb_release_data+0x25d/0x3a0 [ 44.687233][ C0] skb_release_all+0x44/0x60 [ 44.691838][ C0] __kfree_skb+0x1f/0x30 [ 44.696054][ C0] tcp_recvmsg+0xf59/0x1a30 [ 44.700570][ C0] inet_recvmsg+0xbb/0x250 [ 44.704961][ C0] sock_recvmsg+0x92/0xb0 [ 44.709262][ C0] sock_read_iter+0x15f/0x1e0 [ 44.714030][ C0] new_sync_read+0x389/0x4f0 [ 44.718593][ C0] __vfs_read+0xb1/0xc0 [ 44.722738][ C0] vfs_read+0x143/0x2c0 [ 44.726860][ C0] [ 44.729167][ C0] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 0: [ 44.736703][ C0] __zone_watermark_ok+0x106/0x240 [ 44.741790][ C0] get_page_from_freelist+0x629/0x2300 [ 44.747239][ C0] __alloc_pages_nodemask+0x255/0x4d0 [ 44.752584][ C0] alloc_pages_current+0xd1/0x170 [ 44.757587][ C0] skb_page_frag_refill+0x16f/0x260 [ 44.762761][ C0] try_fill_recv+0x51f/0xdc0 [ 44.767326][ C0] virtnet_poll+0x64c/0x7d0 [ 44.771803][ C0] net_rx_action+0x3ae/0xa50 [ 44.776369][ C0] __do_softirq+0x115/0x33f [ 44.780845][ C0] run_ksoftirqd+0x46/0x60 [ 44.785240][ C0] smpboot_thread_fn+0x37d/0x4a0 [ 44.790164][ C0] kthread+0x1d4/0x200 [ 44.794224][ C0] ret_from_fork+0x1f/0x30 [ 44.798611][ C0] [ 44.800910][ C0] Reported by Kernel Concurrency Sanitizer on: [ 44.807039][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0+ #0 [ 44.813941][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.823987][ C0] ================================================================== [ 44.832022][ C0] Kernel panic - not syncing: panic_on_warn set ... [ 44.838589][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0+ #0 [ 44.845492][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.855520][ C0] Call Trace: [ 44.858811][ C0] dump_stack+0xf5/0x159 [ 44.863036][ C0] panic+0x209/0x639 [ 44.866909][ C0] ? __do_softirq+0x115/0x33f [ 44.871558][ C0] ? vprintk_func+0x8d/0x140 [ 44.876127][ C0] kcsan_report.cold+0xc/0x1b [ 44.880787][ C0] __kcsan_setup_watchpoint+0x3ee/0x510 [ 44.886316][ C0] __tsan_read8+0x2c/0x30 [ 44.890625][ C0] __zone_watermark_ok+0x106/0x240 [ 44.895716][ C0] get_page_from_freelist+0x629/0x2300 [ 44.901183][ C0] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 44.907405][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 44.913041][ C0] ? __tsan_read8+0x2c/0x30 [ 44.917583][ C0] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 44.923811][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 44.929432][ C0] __alloc_pages_nodemask+0x255/0x4d0 [ 44.934796][ C0] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 44.941042][ C0] alloc_pages_current+0xd1/0x170 [ 44.946062][ C0] skb_page_frag_refill+0x16f/0x260 [ 44.951250][ C0] try_fill_recv+0x51f/0xdc0 [ 44.955839][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 44.961465][ C0] virtnet_poll+0x64c/0x7d0 [ 44.965961][ C0] net_rx_action+0x3ae/0xa50 [ 44.970546][ C0] __do_softirq+0x115/0x33f [ 44.975035][ C0] ? takeover_tasklets+0x250/0x250 [ 44.980125][ C0] run_ksoftirqd+0x46/0x60 [ 44.984523][ C0] smpboot_thread_fn+0x37d/0x4a0 [ 44.989437][ C0] kthread+0x1d4/0x200 [ 44.993485][ C0] ? constant_test_bit.constprop.0+0x30/0x30 [ 44.999441][ C0] ? kthread_bind+0x50/0x50 [ 45.003919][ C0] ret_from_fork+0x1f/0x30 [ 45.009660][ C0] Kernel Offset: disabled [ 45.013997][ C0] Rebooting in 86400 seconds..