[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 39.845652][ T23] audit: type=1800 audit(1571792448.601:25): pid=7051 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 39.872708][ T23] audit: type=1800 audit(1571792448.601:26): pid=7051 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 39.904656][ T23] audit: type=1800 audit(1571792448.601:27): pid=7051 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 '10.128.0.34' (ECDSA) to the list of known hosts. 2019/10/23 01:00:58 fuzzer started 2019/10/23 01:01:00 dialing manager at 10.128.0.105:33369 2019/10/23 01:01:00 syscalls: 2524 2019/10/23 01:01:00 code coverage: enabled 2019/10/23 01:01:00 comparison tracing: enabled 2019/10/23 01:01:00 extra coverage: extra coverage is not supported by the kernel 2019/10/23 01:01:00 setuid sandbox: enabled 2019/10/23 01:01:00 namespace sandbox: enabled 2019/10/23 01:01:00 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 01:01:00 fault injection: enabled 2019/10/23 01:01:00 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 01:01:00 net packet injection: enabled 2019/10/23 01:01:00 net device setup: enabled 2019/10/23 01:01:00 concurrency sanitizer: enabled syzkaller login: [ 51.675103][ T7209] ================================================================== [ 51.683371][ T7209] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 51.691066][ T7209] [ 51.693374][ T7209] write to 0xffff888120c9e9ec of 4 bytes by interrupt on cpu 1: [ 51.700983][ T7209] tcp_add_backlog+0x4a0/0xcc0 [ 51.705724][ T7209] tcp_v4_rcv+0x1a60/0x1bb0 [ 51.710203][ T7209] ip_protocol_deliver_rcu+0x4d/0x420 [ 51.715548][ T7209] ip_local_deliver_finish+0x110/0x140 [ 51.720978][ T7209] ip_local_deliver+0x133/0x210 [ 51.725799][ T7209] ip_rcv_finish+0x121/0x160 [ 51.730360][ T7209] ip_rcv+0x18f/0x1a0 [ 51.734318][ T7209] __netif_receive_skb_one_core+0xa7/0xe0 [ 51.740032][ T7209] __netif_receive_skb+0x37/0xf0 [ 51.744989][ T7209] netif_receive_skb_internal+0x59/0x190 [ 51.750637][ T7209] napi_gro_receive+0x28f/0x330 [ 51.755464][ T7209] receive_buf+0x284/0x30b0 [ 51.759940][ T7209] virtnet_poll+0x436/0x7d0 [ 51.764416][ T7209] net_rx_action+0x3ae/0xa90 [ 51.768976][ T7209] [ 51.771285][ T7209] read to 0xffff888120c9e9ec of 4 bytes by task 7209 on cpu 0: [ 51.778803][ T7209] __tcp_select_window+0x6b/0x4d0 [ 51.783889][ T7209] __tcp_transmit_skb+0x700/0x1d60 [ 51.788989][ T7209] __tcp_send_ack+0x246/0x300 [ 51.793640][ T7209] tcp_send_ack+0x34/0x40 [ 51.797943][ T7209] tcp_cleanup_rbuf+0x130/0x360 [ 51.802789][ T7209] tcp_recvmsg+0x633/0x1a30 [ 51.807269][ T7209] inet_recvmsg+0xbb/0x250 [ 51.811676][ T7209] sock_recvmsg+0x92/0xb0 [ 51.815977][ T7209] sock_read_iter+0x15f/0x1e0 [ 51.820645][ T7209] new_sync_read+0x389/0x4f0 [ 51.825209][ T7209] __vfs_read+0xb1/0xc0 [ 51.829341][ T7209] vfs_read+0x143/0x2c0 [ 51.833468][ T7209] ksys_read+0xd5/0x1b0 [ 51.837590][ T7209] [ 51.839892][ T7209] Reported by Kernel Concurrency Sanitizer on: [ 51.846025][ T7209] CPU: 0 PID: 7209 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 51.853453][ T7209] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.863501][ T7209] ================================================================== [ 51.871534][ T7209] Kernel panic - not syncing: panic_on_warn set ... [ 51.878097][ T7209] CPU: 0 PID: 7209 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 51.885521][ T7209] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.895555][ T7209] Call Trace: [ 51.898998][ T7209] dump_stack+0xf5/0x159 [ 51.903222][ T7209] panic+0x210/0x640 [ 51.907111][ T7209] ? sock_read_iter+0x15f/0x1e0 [ 51.911945][ T7209] ? vprintk_func+0x8d/0x140 [ 51.916515][ T7209] kcsan_report.cold+0xc/0x10 [ 51.921172][ T7209] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 51.926707][ T7209] __tsan_read4+0x2c/0x30 [ 51.931020][ T7209] __tcp_select_window+0x6b/0x4d0 [ 51.936025][ T7209] __tcp_transmit_skb+0x700/0x1d60 [ 51.941120][ T7209] __tcp_send_ack+0x246/0x300 [ 51.945772][ T7209] tcp_send_ack+0x34/0x40 [ 51.950080][ T7209] tcp_cleanup_rbuf+0x130/0x360 [ 51.954909][ T7209] tcp_recvmsg+0x633/0x1a30 [ 51.959534][ T7209] inet_recvmsg+0xbb/0x250 [ 51.963927][ T7209] ? __tsan_read8+0x2c/0x30 [ 51.968419][ T7209] ? inet_sendpage+0x100/0x100 [ 51.973175][ T7209] sock_recvmsg+0x92/0xb0 [ 51.977487][ T7209] sock_read_iter+0x15f/0x1e0 [ 51.982158][ T7209] new_sync_read+0x389/0x4f0 [ 51.986729][ T7209] __vfs_read+0xb1/0xc0 [ 51.990877][ T7209] vfs_read+0x143/0x2c0 [ 51.995013][ T7209] ksys_read+0xd5/0x1b0 [ 51.999149][ T7209] __x64_sys_read+0x4c/0x60 [ 52.003648][ T7209] do_syscall_64+0xcc/0x370 [ 52.008142][ T7209] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.014020][ T7209] RIP: 0033:0x47c530 [ 52.017899][ T7209] 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 [ 52.037489][ T7209] RSP: 002b:000000c42032b7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 52.045885][ T7209] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 52.053846][ T7209] RDX: 0000000000001000 RSI: 000000c42019c000 RDI: 0000000000000003 [ 52.061794][ T7209] RBP: 000000c42032b830 R08: 0000000000000000 R09: 0000000000000000 [ 52.069741][ T7209] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000009 [ 52.077773][ T7209] R13: 000000c4200225a0 R14: 0000000000000004 R15: ffffffffffffffff [ 52.087247][ T7209] Kernel Offset: disabled [ 52.091571][ T7209] Rebooting in 86400 seconds..