[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 37.588050][ T26] audit: type=1800 audit(1570896448.683:25): pid=7100 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 37.615631][ T26] audit: type=1800 audit(1570896448.683:26): pid=7100 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 37.655348][ T26] audit: type=1800 audit(1570896448.683:27): pid=7100 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 '10.128.0.226' (ECDSA) to the list of known hosts. 2019/10/12 16:07:39 fuzzer started 2019/10/12 16:07:40 dialing manager at 10.128.0.105:43913 2019/10/12 16:07:40 syscalls: 2523 2019/10/12 16:07:40 code coverage: enabled 2019/10/12 16:07:40 comparison tracing: enabled 2019/10/12 16:07:40 extra coverage: extra coverage is not supported by the kernel 2019/10/12 16:07:40 setuid sandbox: enabled 2019/10/12 16:07:40 namespace sandbox: enabled 2019/10/12 16:07:40 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/12 16:07:40 fault injection: enabled 2019/10/12 16:07:40 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/12 16:07:40 net packet injection: enabled 2019/10/12 16:07:40 net device setup: enabled 2019/10/12 16:07:40 concurrency sanitizer: enabled syzkaller login: [ 49.328828][ T7268] ================================================================== [ 49.337506][ T7268] BUG: KCSAN: data-race in tcp_add_backlog / tcp_try_rmem_schedule [ 49.345576][ T7268] [ 49.348185][ T7268] read to 0xffff88812643a14c of 4 bytes by interrupt on cpu 1: [ 49.355759][ T7268] tcp_add_backlog+0x43/0xcc0 [ 49.360434][ T7268] tcp_v4_rcv+0x1aba/0x1bf0 [ 49.364928][ T7268] ip_protocol_deliver_rcu+0x51/0x470 [ 49.370302][ T7268] ip_local_deliver_finish+0x110/0x140 [ 49.375780][ T7268] ip_local_deliver+0x133/0x210 [ 49.380632][ T7268] ip_rcv_finish+0x121/0x160 [ 49.385217][ T7268] ip_rcv+0x18f/0x1a0 [ 49.389186][ T7268] __netif_receive_skb_one_core+0xa7/0xe0 [ 49.394894][ T7268] __netif_receive_skb+0x37/0xf0 [ 49.399956][ T7268] netif_receive_skb_internal+0x59/0x190 [ 49.405655][ T7268] napi_gro_receive+0x28f/0x330 [ 49.410484][ T7268] receive_buf+0x284/0x30b0 [ 49.414963][ T7268] virtnet_poll+0x436/0x7d0 [ 49.419441][ T7268] net_rx_action+0x3ae/0xa50 [ 49.424000][ T7268] [ 49.426413][ T7268] write to 0xffff88812643a14c of 4 bytes by task 7268 on cpu 0: [ 49.434232][ T7268] tcp_try_rmem_schedule+0x294/0xb90 [ 49.439535][ T7268] tcp_data_queue+0x7ba/0x2000 [ 49.444299][ T7268] tcp_rcv_established+0x517/0xf50 [ 49.449761][ T7268] tcp_v4_do_rcv+0x381/0x4e0 [ 49.454351][ T7268] __release_sock+0x135/0x1e0 [ 49.459043][ T7268] release_sock+0x61/0x160 [ 49.463444][ T7268] tcp_recvmsg+0x63b/0x1a30 [ 49.467929][ T7268] inet_recvmsg+0xbb/0x250 [ 49.472329][ T7268] sock_recvmsg+0x92/0xb0 [ 49.476728][ T7268] sock_read_iter+0x15f/0x1e0 [ 49.481434][ T7268] new_sync_read+0x389/0x4f0 [ 49.486017][ T7268] __vfs_read+0xb1/0xc0 [ 49.490167][ T7268] vfs_read+0x143/0x2c0 [ 49.494309][ T7268] [ 49.496644][ T7268] Reported by Kernel Concurrency Sanitizer on: [ 49.502787][ T7268] CPU: 0 PID: 7268 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 49.510079][ T7268] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.520129][ T7268] ================================================================== [ 49.528175][ T7268] Kernel panic - not syncing: panic_on_warn set ... [ 49.534838][ T7268] CPU: 0 PID: 7268 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 49.541944][ T7268] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.552157][ T7268] Call Trace: [ 49.555492][ T7268] dump_stack+0xf5/0x159 [ 49.559725][ T7268] panic+0x209/0x639 [ 49.563695][ T7268] ? sock_recvmsg+0x92/0xb0 [ 49.568206][ T7268] ? vprintk_func+0x8d/0x140 [ 49.572798][ T7268] kcsan_report.cold+0xc/0x1b [ 49.577732][ T7268] __kcsan_setup_watchpoint+0x3ee/0x510 [ 49.583272][ T7268] __tsan_write4+0x32/0x40 [ 49.587881][ T7268] tcp_try_rmem_schedule+0x294/0xb90 [ 49.593517][ T7268] tcp_data_queue+0x7ba/0x2000 [ 49.598384][ T7268] ? tcp_urg+0xa1/0x5c0 [ 49.602662][ T7268] tcp_rcv_established+0x517/0xf50 [ 49.607835][ T7268] ? ipv4_dst_check+0xc6/0xf0 [ 49.612510][ T7268] tcp_v4_do_rcv+0x381/0x4e0 [ 49.617192][ T7268] __release_sock+0x135/0x1e0 [ 49.621868][ T7268] release_sock+0x61/0x160 [ 49.626270][ T7268] tcp_recvmsg+0x63b/0x1a30 [ 49.630761][ T7268] ? preempt_schedule_common+0x37/0x90 [ 49.636209][ T7268] ? __kcsan_setup_watchpoint+0x96/0x510 [ 49.641829][ T7268] inet_recvmsg+0xbb/0x250 [ 49.646244][ T7268] ? __tsan_read8+0x2c/0x30 [ 49.650732][ T7268] ? inet_sendpage+0x100/0x100 [ 49.655479][ T7268] sock_recvmsg+0x92/0xb0 [ 49.659896][ T7268] sock_read_iter+0x15f/0x1e0 [ 49.664565][ T7268] new_sync_read+0x389/0x4f0 [ 49.669166][ T7268] __vfs_read+0xb1/0xc0 [ 49.673315][ T7268] vfs_read+0x143/0x2c0 [ 49.677541][ T7268] ksys_read+0xd5/0x1b0 [ 49.681686][ T7268] __x64_sys_read+0x4c/0x60 [ 49.686207][ T7268] do_syscall_64+0xcf/0x2f0 [ 49.690810][ T7268] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.696990][ T7268] RIP: 0033:0x47c530 [ 49.701141][ T7268] 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 [ 49.721078][ T7268] RSP: 002b:000000c4202c3810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 49.729485][ T7268] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 49.737450][ T7268] RDX: 0000000000001000 RSI: 000000c420236000 RDI: 0000000000000003 [ 49.745502][ T7268] RBP: 000000c4202c3868 R08: 0000000000000000 R09: 0000000000000000 [ 49.753867][ T7268] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 [ 49.762176][ T7268] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 49.772481][ T7268] Kernel Offset: disabled [ 49.777338][ T7268] Rebooting in 86400 seconds..