[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.343757][ T25] audit: type=1800 audit(1570982668.740:25): pid=7067 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.386617][ T25] audit: type=1800 audit(1570982668.740:26): pid=7067 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.411289][ T25] audit: type=1800 audit(1570982668.740:27): pid=7067 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 '10.128.0.159' (ECDSA) to the list of known hosts. 2019/10/13 16:04:38 fuzzer started 2019/10/13 16:04:40 dialing manager at 10.128.0.105:40973 2019/10/13 16:04:40 syscalls: 2523 2019/10/13 16:04:40 code coverage: enabled 2019/10/13 16:04:40 comparison tracing: enabled 2019/10/13 16:04:40 extra coverage: extra coverage is not supported by the kernel 2019/10/13 16:04:40 setuid sandbox: enabled 2019/10/13 16:04:40 namespace sandbox: enabled 2019/10/13 16:04:40 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/13 16:04:40 fault injection: enabled 2019/10/13 16:04:40 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/13 16:04:40 net packet injection: enabled 2019/10/13 16:04:40 net device setup: enabled 2019/10/13 16:04:40 concurrency sanitizer: enabled syzkaller login: [ 46.965107][ T7220] ================================================================== [ 46.973231][ T7220] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 46.980748][ T7220] [ 46.983062][ T7220] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 1: [ 46.990590][ T7220] __zone_watermark_ok+0x106/0x240 [ 46.995685][ T7220] get_page_from_freelist+0x629/0x2300 [ 47.001129][ T7220] __alloc_pages_nodemask+0x255/0x4d0 [ 47.006482][ T7220] alloc_pages_current+0xd1/0x170 [ 47.011491][ T7220] skb_page_frag_refill+0x16f/0x260 [ 47.016674][ T7220] try_fill_recv+0x51f/0xdc0 [ 47.021246][ T7220] virtnet_poll+0x64c/0x7d0 [ 47.025739][ T7220] net_rx_action+0x3ae/0xa50 [ 47.030325][ T7220] __do_softirq+0x115/0x33f [ 47.034812][ T7220] run_ksoftirqd+0x46/0x60 [ 47.039296][ T7220] smpboot_thread_fn+0x37d/0x4a0 [ 47.044218][ T7220] kthread+0x1d4/0x200 [ 47.048268][ T7220] ret_from_fork+0x1f/0x30 [ 47.052666][ T7220] [ 47.054980][ T7220] write to 0xffff88812fffcf58 of 8 bytes by task 7220 on cpu 0: [ 47.062602][ T7220] free_one_page+0x214/0x840 [ 47.067176][ T7220] __free_pages_ok+0x370/0x640 [ 47.071928][ T7220] free_compound_page+0x3d/0x50 [ 47.076768][ T7220] __put_compound_page+0x4e/0x70 [ 47.081687][ T7220] __put_page+0x54/0xd0 [ 47.085851][ T7220] skb_release_data+0x1ba/0x3a0 [ 47.090683][ T7220] skb_release_all+0x44/0x60 [ 47.095521][ T7220] __kfree_skb+0x1f/0x30 [ 47.099753][ T7220] tcp_recvmsg+0xf59/0x1a30 [ 47.104236][ T7220] inet_recvmsg+0xbb/0x250 [ 47.108631][ T7220] sock_recvmsg+0x92/0xb0 [ 47.112941][ T7220] sock_read_iter+0x15f/0x1e0 [ 47.117602][ T7220] new_sync_read+0x389/0x4f0 [ 47.122165][ T7220] [ 47.124471][ T7220] Reported by Kernel Concurrency Sanitizer on: [ 47.130606][ T7220] CPU: 0 PID: 7220 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.137693][ T7220] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.147728][ T7220] ================================================================== [ 47.155771][ T7220] Kernel panic - not syncing: panic_on_warn set ... [ 47.162344][ T7220] CPU: 0 PID: 7220 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.169425][ T7220] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.179456][ T7220] Call Trace: [ 47.182742][ T7220] dump_stack+0xf5/0x159 [ 47.186973][ T7220] panic+0x209/0x639 [ 47.190852][ T7220] ? tcp_recvmsg+0xf59/0x1a30 [ 47.195512][ T7220] ? vprintk_func+0x8d/0x140 [ 47.200090][ T7220] kcsan_report.cold+0xc/0x1b [ 47.204753][ T7220] __kcsan_setup_watchpoint+0x3ee/0x510 [ 47.210332][ T7220] __tsan_write8+0x32/0x40 [ 47.214735][ T7220] free_one_page+0x214/0x840 [ 47.219410][ T7220] __free_pages_ok+0x370/0x640 [ 47.224162][ T7220] free_compound_page+0x3d/0x50 [ 47.228995][ T7220] __put_compound_page+0x4e/0x70 [ 47.233915][ T7220] __put_page+0x54/0xd0 [ 47.238056][ T7220] skb_release_data+0x1ba/0x3a0 [ 47.242894][ T7220] skb_release_all+0x44/0x60 [ 47.247477][ T7220] __kfree_skb+0x1f/0x30 [ 47.251703][ T7220] tcp_recvmsg+0xf59/0x1a30 [ 47.256208][ T7220] inet_recvmsg+0xbb/0x250 [ 47.260608][ T7220] ? __tsan_read8+0x2c/0x30 [ 47.265096][ T7220] ? inet_sendpage+0x100/0x100 [ 47.269843][ T7220] sock_recvmsg+0x92/0xb0 [ 47.274156][ T7220] sock_read_iter+0x15f/0x1e0 [ 47.278825][ T7220] new_sync_read+0x389/0x4f0 [ 47.283408][ T7220] __vfs_read+0xb1/0xc0 [ 47.287553][ T7220] vfs_read+0x143/0x2c0 [ 47.291697][ T7220] ksys_read+0xd5/0x1b0 [ 47.295851][ T7220] __x64_sys_read+0x4c/0x60 [ 47.300341][ T7220] do_syscall_64+0xcf/0x2f0 [ 47.304853][ T7220] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.310724][ T7220] RIP: 0033:0x47c530 [ 47.314616][ T7220] 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 [ 47.334202][ T7220] RSP: 002b:000000c4203177d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.342596][ T7220] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.350574][ T7220] RDX: 0000000000001000 RSI: 000000c4202b4000 RDI: 0000000000000003 [ 47.361566][ T7220] RBP: 000000c420317830 R08: 0000000000000000 R09: 0000000000000000 [ 47.369522][ T7220] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000020 [ 47.377485][ T7220] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 48.513210][ T7220] Shutting down cpus with NMI [ 48.519119][ T7220] Kernel Offset: disabled [ 48.523440][ T7220] Rebooting in 86400 seconds..