[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.444863][ T25] audit: type=1800 audit(1571588617.157:25): pid=7079 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.488439][ T25] audit: type=1800 audit(1571588617.157:26): pid=7079 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.517530][ T25] audit: type=1800 audit(1571588617.157:27): pid=7079 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 '10.128.0.239' (ECDSA) to the list of known hosts. 2019/10/20 16:23:44 fuzzer started 2019/10/20 16:23:45 dialing manager at 10.128.0.105:43535 2019/10/20 16:23:45 syscalls: 2524 2019/10/20 16:23:45 code coverage: enabled 2019/10/20 16:23:45 comparison tracing: enabled 2019/10/20 16:23:45 extra coverage: extra coverage is not supported by the kernel 2019/10/20 16:23:45 setuid sandbox: enabled 2019/10/20 16:23:45 namespace sandbox: enabled 2019/10/20 16:23:45 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/20 16:23:45 fault injection: enabled 2019/10/20 16:23:45 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/20 16:23:45 net packet injection: enabled 2019/10/20 16:23:45 net device setup: enabled 2019/10/20 16:23:45 concurrency sanitizer: enabled syzkaller login: [ 45.194943][ T7232] ================================================================== [ 45.203071][ T7232] BUG: KCSAN: data-race in tcp_add_backlog / tcp_rcv_space_adjust [ 45.210844][ T7232] [ 45.213153][ T7232] read to 0xffff888121346a4c of 4 bytes by interrupt on cpu 0: [ 45.221457][ T7232] tcp_add_backlog+0x43/0xcc0 [ 45.226125][ T7232] tcp_v4_rcv+0x1a60/0x1bb0 [ 45.230606][ T7232] ip_protocol_deliver_rcu+0x4d/0x420 [ 45.235984][ T7232] ip_local_deliver_finish+0x110/0x140 [ 45.241424][ T7232] ip_local_deliver+0x133/0x210 [ 45.246247][ T7232] ip_rcv_finish+0x121/0x160 [ 45.250810][ T7232] ip_rcv+0x18f/0x1a0 [ 45.254770][ T7232] __netif_receive_skb_one_core+0xa7/0xe0 [ 45.260463][ T7232] __netif_receive_skb+0x37/0xf0 [ 45.265383][ T7232] netif_receive_skb_internal+0x59/0x190 [ 45.270990][ T7232] napi_gro_receive+0x28f/0x330 [ 45.275822][ T7232] receive_buf+0x284/0x30b0 [ 45.280306][ T7232] virtnet_poll+0x436/0x7d0 [ 45.284790][ T7232] net_rx_action+0x3ae/0xa90 [ 45.289347][ T7232] [ 45.291652][ T7232] write to 0xffff888121346a4c of 4 bytes by task 7232 on cpu 1: [ 45.299265][ T7232] tcp_rcv_space_adjust+0x40f/0x4c0 [ 45.304440][ T7232] tcp_recvmsg+0xdaa/0x1a30 [ 45.308918][ T7232] inet_recvmsg+0xbb/0x250 [ 45.313342][ T7232] sock_recvmsg+0x92/0xb0 [ 45.317657][ T7232] sock_read_iter+0x15f/0x1e0 [ 45.322337][ T7232] new_sync_read+0x389/0x4f0 [ 45.326923][ T7232] __vfs_read+0xb1/0xc0 [ 45.331052][ T7232] vfs_read+0x143/0x2c0 [ 45.335196][ T7232] ksys_read+0xd5/0x1b0 [ 45.339330][ T7232] __x64_sys_read+0x4c/0x60 [ 45.343819][ T7232] do_syscall_64+0xcc/0x370 [ 45.348296][ T7232] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 45.354154][ T7232] [ 45.356453][ T7232] Reported by Kernel Concurrency Sanitizer on: [ 45.362598][ T7232] CPU: 1 PID: 7232 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 45.370034][ T7232] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.380061][ T7232] ================================================================== [ 45.388095][ T7232] Kernel panic - not syncing: panic_on_warn set ... [ 45.394666][ T7232] CPU: 1 PID: 7232 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 45.402099][ T7232] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.412135][ T7232] Call Trace: [ 45.415405][ T7232] dump_stack+0xf5/0x159 [ 45.419650][ T7232] panic+0x210/0x640 [ 45.423539][ T7232] ? ksys_read+0xd5/0x1b0 [ 45.427846][ T7232] ? vprintk_func+0x8d/0x140 [ 45.432441][ T7232] kcsan_report.cold+0xc/0x10 [ 45.437108][ T7232] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 45.442631][ T7232] __tsan_write4+0x32/0x40 [ 45.447036][ T7232] tcp_rcv_space_adjust+0x40f/0x4c0 [ 45.452215][ T7232] tcp_recvmsg+0xdaa/0x1a30 [ 45.456701][ T7232] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 45.462321][ T7232] inet_recvmsg+0xbb/0x250 [ 45.466734][ T7232] ? __tsan_read8+0x2c/0x30 [ 45.471251][ T7232] ? inet_sendpage+0x100/0x100 [ 45.476021][ T7232] sock_recvmsg+0x92/0xb0 [ 45.480333][ T7232] sock_read_iter+0x15f/0x1e0 [ 45.484994][ T7232] new_sync_read+0x389/0x4f0 [ 45.489573][ T7232] __vfs_read+0xb1/0xc0 [ 45.493708][ T7232] vfs_read+0x143/0x2c0 [ 45.497840][ T7232] ksys_read+0xd5/0x1b0 [ 45.501980][ T7232] __x64_sys_read+0x4c/0x60 [ 45.506477][ T7232] do_syscall_64+0xcc/0x370 [ 45.510958][ T7232] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 45.516829][ T7232] RIP: 0033:0x47c530 [ 45.520715][ T7232] 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 [ 45.540300][ T7232] RSP: 002b:000000c4201c4810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 45.548698][ T7232] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 45.556654][ T7232] RDX: 0000000000001000 RSI: 000000c420184000 RDI: 0000000000000003 [ 45.564610][ T7232] RBP: 000000c4201c4868 R08: 0000000000000000 R09: 0000000000000000 [ 45.572566][ T7232] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 [ 45.580520][ T7232] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 45.589799][ T7232] Kernel Offset: disabled [ 45.594134][ T7232] Rebooting in 86400 seconds..