[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.910492][ T26] audit: type=1800 audit(1570891719.913:25): pid=7046 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.957759][ T26] audit: type=1800 audit(1570891719.913:26): pid=7046 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.990738][ T26] audit: type=1800 audit(1570891719.913:27): pid=7046 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 '10.128.10.27' (ECDSA) to the list of known hosts. 2019/10/12 14:48:51 fuzzer started 2019/10/12 14:48:52 dialing manager at 10.128.0.105:43913 2019/10/12 14:48:52 syscalls: 2523 2019/10/12 14:48:52 code coverage: enabled 2019/10/12 14:48:52 comparison tracing: enabled 2019/10/12 14:48:52 extra coverage: extra coverage is not supported by the kernel 2019/10/12 14:48:52 setuid sandbox: enabled 2019/10/12 14:48:52 namespace sandbox: enabled 2019/10/12 14:48:52 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/12 14:48:52 fault injection: enabled 2019/10/12 14:48:52 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/12 14:48:52 net packet injection: enabled 2019/10/12 14:48:52 net device setup: enabled 2019/10/12 14:48:52 concurrency sanitizer: enabled syzkaller login: [ 47.661469][ T7210] ================================================================== [ 47.671353][ T7210] BUG: KCSAN: data-race in __zone_watermark_ok / free_one_page [ 47.681193][ T7210] [ 47.684221][ T7210] read to 0xffff88812fffcf58 of 8 bytes by interrupt on cpu 0: [ 47.693304][ T7210] __zone_watermark_ok+0x106/0x240 [ 47.700629][ T7210] get_page_from_freelist+0x629/0x2300 [ 47.708346][ T7210] __alloc_pages_nodemask+0x255/0x4d0 [ 47.715113][ T7210] alloc_pages_current+0xd1/0x170 [ 47.722465][ T7210] skb_page_frag_refill+0x16f/0x260 [ 47.729246][ T7210] try_fill_recv+0x51f/0xdc0 [ 47.734534][ T7210] virtnet_poll+0x64c/0x7d0 [ 47.739736][ T7210] net_rx_action+0x3ae/0xa50 [ 47.745378][ T7210] __do_softirq+0x115/0x33f [ 47.750441][ T7210] run_ksoftirqd+0x46/0x60 [ 47.755092][ T7210] smpboot_thread_fn+0x37d/0x4a0 [ 47.761165][ T7210] kthread+0x1d4/0x200 [ 47.768276][ T7210] ret_from_fork+0x1f/0x30 [ 47.774098][ T7210] [ 47.776939][ T7210] write to 0xffff88812fffcf58 of 8 bytes by task 7210 on cpu 1: [ 47.786875][ T7210] free_one_page+0x214/0x840 [ 47.792672][ T7210] __free_pages_ok+0x370/0x640 [ 47.798256][ T7210] free_compound_page+0x3d/0x50 [ 47.804232][ T7210] __put_compound_page+0x4e/0x70 [ 47.810078][ T7210] __put_page+0x54/0xd0 [ 47.814858][ T7210] skb_release_data+0x1ba/0x3a0 [ 47.821038][ T7210] skb_release_all+0x44/0x60 [ 47.827486][ T7210] __kfree_skb+0x1f/0x30 [ 47.832511][ T7210] tcp_recvmsg+0xf59/0x1a30 [ 47.837192][ T7210] inet_recvmsg+0xbb/0x250 [ 47.842248][ T7210] sock_recvmsg+0x92/0xb0 [ 47.846691][ T7210] sock_read_iter+0x15f/0x1e0 [ 47.851613][ T7210] new_sync_read+0x389/0x4f0 [ 47.858454][ T7210] [ 47.861437][ T7210] Reported by Kernel Concurrency Sanitizer on: [ 47.869557][ T7210] CPU: 1 PID: 7210 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.878663][ T7210] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.890369][ T7210] ================================================================== [ 47.900394][ T7210] Kernel panic - not syncing: panic_on_warn set ... [ 47.909151][ T7210] CPU: 1 PID: 7210 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.917586][ T7210] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.931442][ T7210] Call Trace: [ 47.934746][ T7210] dump_stack+0xf5/0x159 [ 47.938997][ T7210] panic+0x209/0x639 [ 47.943211][ T7210] ? tcp_recvmsg+0xf59/0x1a30 [ 47.949492][ T7210] ? vprintk_func+0x8d/0x140 [ 47.954811][ T7210] kcsan_report.cold+0xc/0x1b [ 47.960469][ T7210] __kcsan_setup_watchpoint+0x3ee/0x510 [ 47.967263][ T7210] __tsan_write8+0x32/0x40 [ 47.972328][ T7210] free_one_page+0x214/0x840 [ 47.977651][ T7210] __free_pages_ok+0x370/0x640 [ 47.983036][ T7210] free_compound_page+0x3d/0x50 [ 47.988949][ T7210] __put_compound_page+0x4e/0x70 [ 47.994263][ T7210] __put_page+0x54/0xd0 [ 47.998551][ T7210] skb_release_data+0x1ba/0x3a0 [ 48.004212][ T7210] skb_release_all+0x44/0x60 [ 48.009521][ T7210] __kfree_skb+0x1f/0x30 [ 48.014808][ T7210] tcp_recvmsg+0xf59/0x1a30 [ 48.019507][ T7210] ? preempt_schedule_common+0x37/0x90 [ 48.026168][ T7210] inet_recvmsg+0xbb/0x250 [ 48.030923][ T7210] ? __tsan_read8+0x2c/0x30 [ 48.035633][ T7210] ? inet_sendpage+0x100/0x100 [ 48.040979][ T7210] sock_recvmsg+0x92/0xb0 [ 48.046744][ T7210] sock_read_iter+0x15f/0x1e0 [ 48.051983][ T7210] new_sync_read+0x389/0x4f0 [ 48.057868][ T7210] __vfs_read+0xb1/0xc0 [ 48.062438][ T7210] vfs_read+0x143/0x2c0 [ 48.067040][ T7210] ksys_read+0xd5/0x1b0 [ 48.071752][ T7210] __x64_sys_read+0x4c/0x60 [ 48.076266][ T7210] do_syscall_64+0xcf/0x2f0 [ 48.080961][ T7210] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.087220][ T7210] RIP: 0033:0x47c530 [ 48.091331][ T7210] 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 [ 48.114412][ T7210] RSP: 002b:000000c42014d7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 48.123870][ T7210] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.134232][ T7210] RDX: 0000000000001000 RSI: 000000c42037a000 RDI: 0000000000000003 [ 48.143423][ T7210] RBP: 000000c42014d830 R08: 0000000000000000 R09: 0000000000000000 [ 48.153760][ T7210] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000004 [ 48.165598][ T7210] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 49.327550][ T7210] Shutting down cpus with NMI [ 49.335910][ T7210] Kernel Offset: disabled [ 49.341063][ T7210] Rebooting in 86400 seconds..