[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.988552][ T25] audit: type=1800 audit(1570192334.638:25): pid=7170 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.040423][ T25] audit: type=1800 audit(1570192334.638:26): pid=7170 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.062182][ T25] audit: type=1800 audit(1570192334.638:27): pid=7170 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 '10.128.1.34' (ECDSA) to the list of known hosts. 2019/10/04 12:32:32 fuzzer started 2019/10/04 12:32:34 dialing manager at 10.128.0.105:38119 2019/10/04 12:32:34 syscalls: 2523 2019/10/04 12:32:34 code coverage: enabled 2019/10/04 12:32:34 comparison tracing: enabled 2019/10/04 12:32:34 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:32:34 setuid sandbox: enabled 2019/10/04 12:32:34 namespace sandbox: enabled 2019/10/04 12:32:34 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:32:34 fault injection: enabled 2019/10/04 12:32:34 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:32:34 net packet injection: enabled 2019/10/04 12:32:34 net device setup: enabled 2019/10/04 12:32:34 concurrency sanitizer: enabled syzkaller login: [ 58.219970][ T7326] ================================================================== [ 58.228149][ T7326] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0xb8f/0xcc0 [ 58.238012][ T7326] [ 58.240364][ T7326] write to 0xffff8881293949ec of 4 bytes by interrupt on cpu 0: [ 58.248029][ T7326] tcp_add_backlog+0xb8f/0xcc0 [ 58.252769][ T7326] tcp_v4_rcv+0x1aba/0x1bf0 [ 58.257405][ T7326] ip_protocol_deliver_rcu+0x51/0x470 [ 58.263288][ T7326] ip_local_deliver_finish+0x110/0x140 [ 58.268791][ T7326] ip_local_deliver+0x133/0x210 [ 58.273627][ T7326] ip_rcv_finish+0x121/0x160 [ 58.278238][ T7326] ip_rcv+0x18f/0x1a0 [ 58.282216][ T7326] __netif_receive_skb_one_core+0xa7/0xe0 [ 58.287913][ T7326] __netif_receive_skb+0x37/0xf0 [ 58.292838][ T7326] netif_receive_skb_internal+0x59/0x190 [ 58.298472][ T7326] napi_gro_receive+0x28f/0x330 [ 58.303298][ T7326] receive_buf+0x284/0x30b0 [ 58.307877][ T7326] virtnet_poll+0x436/0x7d0 [ 58.312370][ T7326] net_rx_action+0x3ae/0xa50 [ 58.316929][ T7326] [ 58.319235][ T7326] read to 0xffff8881293949ec of 4 bytes by task 7326 on cpu 1: [ 58.327714][ T7326] __tcp_select_window+0x6b/0x4d0 [ 58.332732][ T7326] __tcp_transmit_skb+0x679/0x1cd0 [ 58.337818][ T7326] __tcp_send_ack+0x246/0x300 [ 58.342471][ T7326] tcp_send_ack+0x34/0x40 [ 58.346776][ T7326] tcp_cleanup_rbuf+0x130/0x360 [ 58.351600][ T7326] tcp_recvmsg+0x633/0x1a30 [ 58.356080][ T7326] inet_recvmsg+0xbb/0x250 [ 58.360471][ T7326] sock_recvmsg+0x92/0xb0 [ 58.364777][ T7326] sock_read_iter+0x15f/0x1e0 [ 58.369430][ T7326] new_sync_read+0x389/0x4f0 [ 58.374014][ T7326] __vfs_read+0xb1/0xc0 [ 58.378146][ T7326] vfs_read+0x143/0x2c0 [ 58.382290][ T7326] ksys_read+0xd5/0x1b0 [ 58.386442][ T7326] [ 58.388743][ T7326] Reported by Kernel Concurrency Sanitizer on: [ 58.394876][ T7326] CPU: 1 PID: 7326 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 58.402040][ T7326] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 58.412075][ T7326] ================================================================== [ 58.420122][ T7326] Kernel panic - not syncing: panic_on_warn set ... [ 58.426690][ T7326] CPU: 1 PID: 7326 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 58.433772][ T7326] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 58.443804][ T7326] Call Trace: [ 58.447076][ T7326] dump_stack+0xf5/0x159 [ 58.451312][ T7326] panic+0x209/0x639 [ 58.455198][ T7326] ? vprintk_func+0x8d/0x140 [ 58.459767][ T7326] kcsan_report.cold+0x57/0xeb [ 58.464523][ T7326] __kcsan_setup_watchpoint+0x342/0x500 [ 58.470048][ T7326] __tsan_read4+0x2c/0x30 [ 58.474371][ T7326] __tcp_select_window+0x6b/0x4d0 [ 58.479405][ T7326] __tcp_transmit_skb+0x679/0x1cd0 [ 58.484508][ T7326] __tcp_send_ack+0x246/0x300 [ 58.489163][ T7326] tcp_send_ack+0x34/0x40 [ 58.493469][ T7326] tcp_cleanup_rbuf+0x130/0x360 [ 58.498296][ T7326] tcp_recvmsg+0x633/0x1a30 [ 58.502799][ T7326] inet_recvmsg+0xbb/0x250 [ 58.507207][ T7326] ? __tsan_read8+0x2c/0x30 [ 58.511961][ T7326] ? inet_sendpage+0x100/0x100 [ 58.516705][ T7326] sock_recvmsg+0x92/0xb0 [ 58.521991][ T7326] sock_read_iter+0x15f/0x1e0 [ 58.526656][ T7326] new_sync_read+0x389/0x4f0 [ 58.531229][ T7326] __vfs_read+0xb1/0xc0 [ 58.535363][ T7326] vfs_read+0x143/0x2c0 [ 58.539494][ T7326] ksys_read+0xd5/0x1b0 [ 58.543644][ T7326] __x64_sys_read+0x4c/0x60 [ 58.548129][ T7326] do_syscall_64+0xcf/0x2f0 [ 58.552615][ T7326] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 58.558580][ T7326] RIP: 0033:0x47c530 [ 58.562456][ T7326] 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 [ 58.582047][ T7326] RSP: 002b:000000c42030d7d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 58.590442][ T7326] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 58.598403][ T7326] RDX: 0000000000001000 RSI: 000000c4202be000 RDI: 0000000000000003 [ 58.606374][ T7326] RBP: 000000c42030d828 R08: 0000000000000000 R09: 0000000000000000 [ 58.614321][ T7326] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 [ 58.622272][ T7326] R13: ffffffffffffffff R14: 0000000000000008 R15: ffffffffffffffff [ 58.632031][ T7326] Kernel Offset: disabled [ 58.636389][ T7326] Rebooting in 86400 seconds..