[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.767654][ T25] audit: type=1800 audit(1571164895.523:25): pid=6958 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 38.808598][ T25] audit: type=1800 audit(1571164895.523:26): pid=6958 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 38.829239][ T25] audit: type=1800 audit(1571164895.523:27): pid=6958 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 '10.128.0.96' (ECDSA) to the list of known hosts. 2019/10/15 18:41:47 fuzzer started 2019/10/15 18:41:48 dialing manager at 10.128.0.105:38903 2019/10/15 18:41:48 syscalls: 2523 2019/10/15 18:41:48 code coverage: enabled 2019/10/15 18:41:48 comparison tracing: enabled 2019/10/15 18:41:48 extra coverage: extra coverage is not supported by the kernel 2019/10/15 18:41:48 setuid sandbox: enabled 2019/10/15 18:41:48 namespace sandbox: enabled 2019/10/15 18:41:48 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/15 18:41:48 fault injection: enabled 2019/10/15 18:41:48 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/15 18:41:48 net packet injection: enabled 2019/10/15 18:41:48 net device setup: enabled 2019/10/15 18:41:48 concurrency sanitizer: enabled syzkaller login: [ 51.782228][ T7107] ================================================================== [ 51.790362][ T7107] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 51.797882][ T7107] [ 51.800209][ T7107] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 0: [ 51.807740][ T7107] __zone_watermark_ok+0x106/0x240 [ 51.812835][ T7107] get_page_from_freelist+0x629/0x2300 [ 51.818277][ T7107] __alloc_pages_nodemask+0x255/0x4d0 [ 51.823632][ T7107] alloc_pages_current+0xd1/0x170 [ 51.828640][ T7107] skb_page_frag_refill+0x16f/0x260 [ 51.833820][ T7107] try_fill_recv+0x51f/0xdc0 [ 51.838396][ T7107] virtnet_poll+0x64c/0x7d0 [ 51.842882][ T7107] net_rx_action+0x3ae/0xa50 [ 51.847454][ T7107] __do_softirq+0x115/0x33f [ 51.851937][ T7107] run_ksoftirqd+0x46/0x60 [ 51.856337][ T7107] smpboot_thread_fn+0x37d/0x4a0 [ 51.861256][ T7107] kthread+0x1d4/0x200 [ 51.865304][ T7107] ret_from_fork+0x1f/0x30 [ 51.869693][ T7107] [ 51.872006][ T7107] write to 0xffff88812fffcf58 of 8 bytes by task 7107 on cpu 1: [ 51.879618][ T7107] free_one_page+0x783/0x840 [ 51.884214][ T7107] __free_pages_ok+0x370/0x640 [ 51.888958][ T7107] free_compound_page+0x3d/0x50 [ 51.893789][ T7107] __put_compound_page+0x4e/0x70 [ 51.898706][ T7107] __put_page+0x54/0xd0 [ 51.902844][ T7107] skb_release_data+0x1ba/0x3a0 [ 51.907694][ T7107] skb_release_all+0x44/0x60 [ 51.912264][ T7107] __kfree_skb+0x1f/0x30 [ 51.916501][ T7107] tcp_recvmsg+0xf59/0x1a30 [ 51.920998][ T7107] inet_recvmsg+0xbb/0x250 [ 51.925404][ T7107] sock_recvmsg+0x92/0xb0 [ 51.929714][ T7107] sock_read_iter+0x15f/0x1e0 [ 51.934373][ T7107] new_sync_read+0x389/0x4f0 [ 51.938938][ T7107] [ 51.941256][ T7107] Reported by Kernel Concurrency Sanitizer on: [ 51.947394][ T7107] CPU: 1 PID: 7107 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 51.954483][ T7107] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.964518][ T7107] ================================================================== [ 51.972560][ T7107] Kernel panic - not syncing: panic_on_warn set ... [ 51.979129][ T7107] CPU: 1 PID: 7107 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 51.986389][ T7107] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.996419][ T7107] Call Trace: [ 51.999698][ T7107] dump_stack+0xf5/0x159 [ 52.003928][ T7107] panic+0x209/0x639 [ 52.007807][ T7107] ? tcp_recvmsg+0xf59/0x1a30 [ 52.012492][ T7107] ? vprintk_func+0x8d/0x140 [ 52.017070][ T7107] kcsan_report.cold+0xc/0x1b [ 52.021732][ T7107] __kcsan_setup_watchpoint+0x3ee/0x510 [ 52.027265][ T7107] __tsan_write8+0x32/0x40 [ 52.031668][ T7107] free_one_page+0x783/0x840 [ 52.036266][ T7107] __free_pages_ok+0x370/0x640 [ 52.041023][ T7107] free_compound_page+0x3d/0x50 [ 52.045872][ T7107] __put_compound_page+0x4e/0x70 [ 52.050791][ T7107] __put_page+0x54/0xd0 [ 52.054945][ T7107] skb_release_data+0x1ba/0x3a0 [ 52.059784][ T7107] skb_release_all+0x44/0x60 [ 52.064359][ T7107] __kfree_skb+0x1f/0x30 [ 52.068586][ T7107] tcp_recvmsg+0xf59/0x1a30 [ 52.073085][ T7107] inet_recvmsg+0xbb/0x250 [ 52.077483][ T7107] ? __tsan_read8+0x2c/0x30 [ 52.081972][ T7107] ? inet_sendpage+0x100/0x100 [ 52.086734][ T7107] sock_recvmsg+0x92/0xb0 [ 52.091046][ T7107] sock_read_iter+0x15f/0x1e0 [ 52.095716][ T7107] new_sync_read+0x389/0x4f0 [ 52.100300][ T7107] __vfs_read+0xb1/0xc0 [ 52.104441][ T7107] vfs_read+0x143/0x2c0 [ 52.108584][ T7107] ksys_read+0xd5/0x1b0 [ 52.112729][ T7107] __x64_sys_read+0x4c/0x60 [ 52.117221][ T7107] do_syscall_64+0xcf/0x2f0 [ 52.121711][ T7107] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.127584][ T7107] RIP: 0033:0x47c530 [ 52.131468][ T7107] 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 [ 52.151054][ T7107] RSP: 002b:000000c42087a810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 52.159445][ T7107] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 52.167403][ T7107] RDX: 0000000000001000 RSI: 000000c420380000 RDI: 0000000000000003 [ 52.175445][ T7107] RBP: 000000c42087a868 R08: 0000000000000000 R09: 0000000000000000 [ 52.183408][ T7107] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 [ 52.191360][ T7107] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 53.324172][ T7107] Shutting down cpus with NMI [ 53.330448][ T7107] Kernel Offset: disabled [ 53.334769][ T7107] Rebooting in 86400 seconds..