[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.514860][ T25] audit: type=1800 audit(1572869066.872:25): pid=7005 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 33.534502][ T25] audit: type=1800 audit(1572869066.872:26): pid=7005 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 33.597420][ T25] audit: type=1800 audit(1572869066.952:27): pid=7005 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 '10.128.0.41' (ECDSA) to the list of known hosts. 2019/11/04 12:04:35 fuzzer started 2019/11/04 12:04:36 dialing manager at 10.128.0.105:43623 2019/11/04 12:04:36 syscalls: 2553 2019/11/04 12:04:36 code coverage: enabled 2019/11/04 12:04:36 comparison tracing: enabled 2019/11/04 12:04:36 extra coverage: extra coverage is not supported by the kernel 2019/11/04 12:04:36 setuid sandbox: enabled 2019/11/04 12:04:36 namespace sandbox: enabled 2019/11/04 12:04:36 Android sandbox: /sys/fs/selinux/policy does not exist 2019/11/04 12:04:36 fault injection: enabled 2019/11/04 12:04:36 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/11/04 12:04:36 net packet injection: enabled 2019/11/04 12:04:36 net device setup: enabled 2019/11/04 12:04:36 concurrency sanitizer: enabled 2019/11/04 12:04:36 devlink PCI setup: PCI device 0000:00:10.0 is not available 2019/11/04 12:04:37 adding functions to KCSAN blacklist: 'generic_permission' 'tomoyo_supervisor' 'pipe_poll' '__hrtimer_run_queues' 'find_next_bit' 'generic_fillattr' syzkaller login: [ 43.933009][ T7174] ================================================================== [ 43.941155][ T7174] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 43.948895][ T7174] [ 43.951216][ T7174] write to 0xffff888129326a2c of 4 bytes by interrupt on cpu 0: [ 43.958828][ T7174] tcp_add_backlog+0x4a0/0xcc0 [ 43.963570][ T7174] tcp_v4_rcv+0x1a60/0x1bb0 [ 43.968051][ T7174] ip_protocol_deliver_rcu+0x4d/0x420 [ 43.973400][ T7174] ip_local_deliver_finish+0x110/0x140 [ 43.978838][ T7174] ip_local_deliver+0x133/0x210 [ 43.983662][ T7174] ip_rcv_finish+0x121/0x160 [ 43.988227][ T7174] ip_rcv+0x18f/0x1a0 [ 43.992186][ T7174] __netif_receive_skb_one_core+0xa7/0xe0 [ 43.997882][ T7174] __netif_receive_skb+0x37/0xf0 [ 44.002813][ T7174] netif_receive_skb_internal+0x59/0x190 [ 44.008463][ T7174] napi_gro_receive+0x28f/0x330 [ 44.013301][ T7174] receive_buf+0x284/0x30b0 [ 44.017787][ T7174] virtnet_poll+0x436/0x7d0 [ 44.022273][ T7174] net_rx_action+0x3ae/0xa90 [ 44.026833][ T7174] [ 44.029142][ T7174] read to 0xffff888129326a2c of 4 bytes by task 7174 on cpu 1: [ 44.036662][ T7174] __tcp_select_window+0x6b/0x4d0 [ 44.041664][ T7174] __tcp_transmit_skb+0x700/0x1d60 [ 44.046933][ T7174] __tcp_send_ack+0x246/0x300 [ 44.051590][ T7174] tcp_send_ack+0x34/0x40 [ 44.055907][ T7174] tcp_cleanup_rbuf+0x130/0x360 [ 44.060738][ T7174] tcp_recvmsg+0x633/0x1a30 [ 44.065217][ T7174] inet_recvmsg+0xbb/0x250 [ 44.069625][ T7174] sock_recvmsg+0x92/0xb0 [ 44.073933][ T7174] sock_read_iter+0x15f/0x1e0 [ 44.078587][ T7174] new_sync_read+0x389/0x4f0 [ 44.083151][ T7174] __vfs_read+0xb1/0xc0 [ 44.087291][ T7174] vfs_read+0x143/0x2c0 [ 44.091472][ T7174] ksys_read+0xd5/0x1b0 [ 44.095638][ T7174] [ 44.097941][ T7174] Reported by Kernel Concurrency Sanitizer on: [ 44.104087][ T7174] CPU: 1 PID: 7174 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 44.111516][ T7174] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.121560][ T7174] ================================================================== [ 44.129609][ T7174] Kernel panic - not syncing: panic_on_warn set ... [ 44.136171][ T7174] CPU: 1 PID: 7174 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 44.143599][ T7174] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.153625][ T7174] Call Trace: [ 44.156900][ T7174] dump_stack+0xf5/0x159 [ 44.161121][ T7174] panic+0x210/0x640 [ 44.164996][ T7174] ? sock_read_iter+0x15f/0x1e0 [ 44.169829][ T7174] ? vprintk_func+0x8d/0x140 [ 44.174399][ T7174] kcsan_report.cold+0xc/0x10 [ 44.179058][ T7174] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 44.184599][ T7174] __tsan_read4+0x2c/0x30 [ 44.188909][ T7174] __tcp_select_window+0x6b/0x4d0 [ 44.193910][ T7174] __tcp_transmit_skb+0x700/0x1d60 [ 44.199003][ T7174] __tcp_send_ack+0x246/0x300 [ 44.203672][ T7174] tcp_send_ack+0x34/0x40 [ 44.207980][ T7174] tcp_cleanup_rbuf+0x130/0x360 [ 44.212809][ T7174] tcp_recvmsg+0x633/0x1a30 [ 44.217300][ T7174] inet_recvmsg+0xbb/0x250 [ 44.221692][ T7174] ? __tsan_read8+0x2c/0x30 [ 44.226170][ T7174] ? inet_sendpage+0x100/0x100 [ 44.230909][ T7174] sock_recvmsg+0x92/0xb0 [ 44.235230][ T7174] sock_read_iter+0x15f/0x1e0 [ 44.239901][ T7174] new_sync_read+0x389/0x4f0 [ 44.244477][ T7174] __vfs_read+0xb1/0xc0 [ 44.248617][ T7174] vfs_read+0x143/0x2c0 [ 44.252759][ T7174] ksys_read+0xd5/0x1b0 [ 44.256897][ T7174] __x64_sys_read+0x4c/0x60 [ 44.261397][ T7174] do_syscall_64+0xcc/0x370 [ 44.265880][ T7174] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 44.271746][ T7174] RIP: 0033:0x47c530 [ 44.275637][ T7174] 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 [ 44.295213][ T7174] RSP: 002b:000000c4202d47d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 44.303600][ T7174] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 44.311547][ T7174] RDX: 0000000000001000 RSI: 000000c420054000 RDI: 0000000000000003 [ 44.319534][ T7174] RBP: 000000c4202d4830 R08: 0000000000000000 R09: 0000000000000000 [ 44.327490][ T7174] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000080 [ 44.335439][ T7174] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 44.344709][ T7174] Kernel Offset: disabled [ 44.350074][ T7174] Rebooting in 86400 seconds..