[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 44.478684][ T25] audit: type=1800 audit(1571019535.748:25): pid=7068 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 44.514173][ T25] audit: type=1800 audit(1571019535.748:26): pid=7068 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 44.537587][ T25] audit: type=1800 audit(1571019535.748:27): pid=7068 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 '10.128.1.14' (ECDSA) to the list of known hosts. 2019/10/14 02:19:03 fuzzer started 2019/10/14 02:19:04 dialing manager at 10.128.0.105:40973 2019/10/14 02:19:04 syscalls: 2523 2019/10/14 02:19:04 code coverage: enabled 2019/10/14 02:19:04 comparison tracing: enabled 2019/10/14 02:19:04 extra coverage: extra coverage is not supported by the kernel 2019/10/14 02:19:04 setuid sandbox: enabled 2019/10/14 02:19:04 namespace sandbox: enabled 2019/10/14 02:19:04 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/14 02:19:04 fault injection: enabled 2019/10/14 02:19:04 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/14 02:19:04 net packet injection: enabled 2019/10/14 02:19:04 net device setup: enabled 2019/10/14 02:19:04 concurrency sanitizer: enabled syzkaller login: [ 53.885737][ T7222] ================================================================== [ 53.893876][ T7222] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 53.901404][ T7222] [ 53.903725][ T7222] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 0: [ 53.911271][ T7222] __zone_watermark_ok+0x106/0x240 [ 53.916371][ T7222] get_page_from_freelist+0x629/0x2300 [ 53.921836][ T7222] __alloc_pages_nodemask+0x255/0x4d0 [ 53.927192][ T7222] alloc_pages_current+0xd1/0x170 [ 53.932204][ T7222] skb_page_frag_refill+0x16f/0x260 [ 53.937392][ T7222] try_fill_recv+0x51f/0xdc0 [ 53.941967][ T7222] virtnet_poll+0x64c/0x7d0 [ 53.946452][ T7222] net_rx_action+0x3ae/0xa50 [ 53.951026][ T7222] __do_softirq+0x115/0x33f [ 53.955524][ T7222] run_ksoftirqd+0x46/0x60 [ 53.959927][ T7222] smpboot_thread_fn+0x37d/0x4a0 [ 53.964862][ T7222] kthread+0x1d4/0x200 [ 53.968914][ T7222] ret_from_fork+0x1f/0x30 [ 53.973306][ T7222] [ 53.975623][ T7222] write to 0xffff88812fffcf58 of 8 bytes by task 7222 on cpu 1: [ 53.983237][ T7222] free_one_page+0x214/0x840 [ 53.987824][ T7222] __free_pages_ok+0x370/0x640 [ 53.992578][ T7222] free_compound_page+0x3d/0x50 [ 53.997412][ T7222] __put_compound_page+0x4e/0x70 [ 54.002333][ T7222] __put_page+0x54/0xd0 [ 54.006478][ T7222] skb_release_data+0x1ba/0x3a0 [ 54.011326][ T7222] skb_release_all+0x44/0x60 [ 54.015898][ T7222] __kfree_skb+0x1f/0x30 [ 54.020129][ T7222] tcp_recvmsg+0xf59/0x1a30 [ 54.024616][ T7222] inet_recvmsg+0xbb/0x250 [ 54.029016][ T7222] sock_recvmsg+0x92/0xb0 [ 54.033329][ T7222] sock_read_iter+0x15f/0x1e0 [ 54.037990][ T7222] new_sync_read+0x389/0x4f0 [ 54.042558][ T7222] [ 54.044867][ T7222] Reported by Kernel Concurrency Sanitizer on: [ 54.051438][ T7222] CPU: 1 PID: 7222 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 54.058534][ T7222] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.068588][ T7222] ================================================================== [ 54.076649][ T7222] Kernel panic - not syncing: panic_on_warn set ... [ 54.083242][ T7222] CPU: 1 PID: 7222 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 54.090417][ T7222] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.100453][ T7222] Call Trace: [ 54.103748][ T7222] dump_stack+0xf5/0x159 [ 54.108004][ T7222] panic+0x209/0x639 [ 54.111887][ T7222] ? tcp_recvmsg+0xf59/0x1a30 [ 54.116585][ T7222] ? vprintk_func+0x8d/0x140 [ 54.121169][ T7222] kcsan_report.cold+0xc/0x1b [ 54.125849][ T7222] __kcsan_setup_watchpoint+0x3ee/0x510 [ 54.131381][ T7222] __tsan_write8+0x32/0x40 [ 54.135786][ T7222] free_one_page+0x214/0x840 [ 54.140372][ T7222] __free_pages_ok+0x370/0x640 [ 54.145127][ T7222] free_compound_page+0x3d/0x50 [ 54.149964][ T7222] __put_compound_page+0x4e/0x70 [ 54.154884][ T7222] __put_page+0x54/0xd0 [ 54.159029][ T7222] skb_release_data+0x1ba/0x3a0 [ 54.163871][ T7222] skb_release_all+0x44/0x60 [ 54.168453][ T7222] __kfree_skb+0x1f/0x30 [ 54.172681][ T7222] tcp_recvmsg+0xf59/0x1a30 [ 54.177188][ T7222] inet_recvmsg+0xbb/0x250 [ 54.181675][ T7222] ? __tsan_read8+0x2c/0x30 [ 54.186167][ T7222] ? inet_sendpage+0x100/0x100 [ 54.190935][ T7222] sock_recvmsg+0x92/0xb0 [ 54.195252][ T7222] sock_read_iter+0x15f/0x1e0 [ 54.199931][ T7222] new_sync_read+0x389/0x4f0 [ 54.204514][ T7222] __vfs_read+0xb1/0xc0 [ 54.208658][ T7222] vfs_read+0x143/0x2c0 [ 54.212804][ T7222] ksys_read+0xd5/0x1b0 [ 54.217036][ T7222] __x64_sys_read+0x4c/0x60 [ 54.221531][ T7222] do_syscall_64+0xcf/0x2f0 [ 54.226041][ T7222] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 54.231952][ T7222] RIP: 0033:0x47c530 [ 54.235847][ T7222] Code: 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 49 c7 c2 00 00 00 00 49 c7 c0 00 00 00 00 49 c7 c1 00 00 00 00 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30 [ 54.255434][ T7222] RSP: 002b:000000c4202f3810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 54.263842][ T7222] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 54.271810][ T7222] RDX: 0000000000001000 RSI: 000000c42019c000 RDI: 0000000000000003 [ 54.279764][ T7222] RBP: 000000c4202f3868 R08: 0000000000000000 R09: 0000000000000000 [ 54.287732][ T7222] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000080 [ 54.295688][ T7222] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 55.431383][ T7222] Shutting down cpus with NMI [ 55.437468][ T7222] Kernel Offset: disabled [ 55.441801][ T7222] Rebooting in 86400 seconds..