[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 37.562599][ T26] audit: type=1800 audit(1570909238.113:25): pid=7077 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 37.595072][ T26] audit: type=1800 audit(1570909238.113:26): pid=7077 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 37.616674][ T26] audit: type=1800 audit(1570909238.113:27): pid=7077 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 '10.128.1.62' (ECDSA) to the list of known hosts. 2019/10/12 19:40:47 fuzzer started 2019/10/12 19:40:49 dialing manager at 10.128.0.105:43913 2019/10/12 19:40:49 syscalls: 2523 2019/10/12 19:40:49 code coverage: enabled 2019/10/12 19:40:49 comparison tracing: enabled 2019/10/12 19:40:49 extra coverage: extra coverage is not supported by the kernel 2019/10/12 19:40:49 setuid sandbox: enabled 2019/10/12 19:40:49 namespace sandbox: enabled 2019/10/12 19:40:49 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/12 19:40:49 fault injection: enabled 2019/10/12 19:40:49 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/12 19:40:49 net packet injection: enabled 2019/10/12 19:40:49 net device setup: enabled 2019/10/12 19:40:49 concurrency sanitizer: enabled syzkaller login: [ 49.030754][ C0] ================================================================== [ 49.039029][ C0] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 49.046548][ C0] [ 49.048860][ C0] write to 0xffff88812fffcf58 of 8 bytes by task 7238 on cpu 1: [ 49.056463][ C0] free_one_page+0x214/0x840 [ 49.061029][ C0] __free_pages_ok+0x370/0x640 [ 49.065771][ C0] free_compound_page+0x3d/0x50 [ 49.070599][ C0] __put_compound_page+0x4e/0x70 [ 49.075557][ C0] __put_page+0x54/0xd0 [ 49.079708][ C0] skb_release_data+0x1ba/0x3a0 [ 49.084530][ C0] skb_release_all+0x44/0x60 [ 49.089180][ C0] __kfree_skb+0x1f/0x30 [ 49.093400][ C0] tcp_recvmsg+0xf59/0x1a30 [ 49.097894][ C0] inet_recvmsg+0xbb/0x250 [ 49.102553][ C0] sock_recvmsg+0x92/0xb0 [ 49.106854][ C0] sock_read_iter+0x15f/0x1e0 [ 49.111505][ C0] new_sync_read+0x389/0x4f0 [ 49.116071][ C0] __vfs_read+0xb1/0xc0 [ 49.120205][ C0] [ 49.122522][ C0] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 0: [ 49.130044][ C0] __zone_watermark_ok+0x106/0x240 [ 49.135305][ C0] get_page_from_freelist+0x629/0x2300 [ 49.140826][ C0] __alloc_pages_nodemask+0x255/0x4d0 [ 49.146434][ C0] page_frag_alloc+0x11e/0x2d0 [ 49.151368][ C0] __napi_alloc_skb+0x172/0x210 [ 49.156198][ C0] page_to_skb+0x8d/0x480 [ 49.160514][ C0] receive_buf+0x17c7/0x30b0 [ 49.165101][ C0] virtnet_poll+0x436/0x7d0 [ 49.169586][ C0] net_rx_action+0x3ae/0xa50 [ 49.174159][ C0] __do_softirq+0x115/0x33f [ 49.178693][ C0] run_ksoftirqd+0x46/0x60 [ 49.183087][ C0] smpboot_thread_fn+0x37d/0x4a0 [ 49.188006][ C0] kthread+0x1d4/0x200 [ 49.192044][ C0] [ 49.194351][ C0] Reported by Kernel Concurrency Sanitizer on: [ 49.200476][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0+ #0 [ 49.207466][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.217496][ C0] ================================================================== [ 49.225532][ C0] Kernel panic - not syncing: panic_on_warn set ... [ 49.232101][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0+ #0 [ 49.239008][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.249045][ C0] Call Trace: [ 49.252319][ C0] dump_stack+0xf5/0x159 [ 49.256550][ C0] panic+0x209/0x639 [ 49.260444][ C0] ? net_rx_action+0x3ae/0xa50 [ 49.265192][ C0] ? vprintk_func+0x8d/0x140 [ 49.269771][ C0] kcsan_report.cold+0xc/0x1b [ 49.274430][ C0] __kcsan_setup_watchpoint+0x3ee/0x510 [ 49.279964][ C0] __tsan_read8+0x2c/0x30 [ 49.284307][ C0] __zone_watermark_ok+0x106/0x240 [ 49.289489][ C0] get_page_from_freelist+0x629/0x2300 [ 49.294928][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 49.300549][ C0] ? __tsan_read8+0x2c/0x30 [ 49.305135][ C0] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 49.311350][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 49.316963][ C0] __alloc_pages_nodemask+0x255/0x4d0 [ 49.322315][ C0] page_frag_alloc+0x11e/0x2d0 [ 49.327058][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 49.332677][ C0] __napi_alloc_skb+0x172/0x210 [ 49.337506][ C0] page_to_skb+0x8d/0x480 [ 49.341813][ C0] receive_buf+0x17c7/0x30b0 [ 49.346381][ C0] ? __tsan_write8+0x32/0x40 [ 49.350955][ C0] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 49.356398][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 49.362007][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 49.367712][ C0] virtnet_poll+0x436/0x7d0 [ 49.372200][ C0] net_rx_action+0x3ae/0xa50 [ 49.376772][ C0] __do_softirq+0x115/0x33f [ 49.381255][ C0] ? takeover_tasklets+0x250/0x250 [ 49.386482][ C0] run_ksoftirqd+0x46/0x60 [ 49.390875][ C0] smpboot_thread_fn+0x37d/0x4a0 [ 49.395790][ C0] kthread+0x1d4/0x200 [ 49.399834][ C0] ? constant_test_bit.constprop.0+0x30/0x30 [ 49.405873][ C0] ? kthread_bind+0x50/0x50 [ 49.410366][ C0] ret_from_fork+0x1f/0x30 [ 49.416377][ C0] Kernel Offset: disabled [ 49.420703][ C0] Rebooting in 86400 seconds..