[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 39.276776][ T26] audit: type=1800 audit(1571744500.828:25): pid=6996 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 39.303818][ T26] audit: type=1800 audit(1571744500.838:26): pid=6996 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 39.337731][ T26] audit: type=1800 audit(1571744500.838:27): pid=6996 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 '10.128.0.165' (ECDSA) to the list of known hosts. 2019/10/22 11:41:51 fuzzer started 2019/10/22 11:41:52 dialing manager at 10.128.0.105:37053 2019/10/22 11:41:52 syscalls: 2524 2019/10/22 11:41:52 code coverage: enabled 2019/10/22 11:41:52 comparison tracing: enabled 2019/10/22 11:41:52 extra coverage: extra coverage is not supported by the kernel 2019/10/22 11:41:52 setuid sandbox: enabled 2019/10/22 11:41:52 namespace sandbox: enabled 2019/10/22 11:41:52 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 11:41:52 fault injection: enabled 2019/10/22 11:41:52 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 11:41:52 net packet injection: enabled 2019/10/22 11:41:52 net device setup: enabled 2019/10/22 11:41:52 concurrency sanitizer: enabled syzkaller login: [ 51.497286][ T7147] ================================================================== [ 51.506609][ T7147] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 51.515605][ T7147] [ 51.517920][ T7147] write to 0xffff888124e4612c of 4 bytes by interrupt on cpu 1: [ 51.525545][ T7147] tcp_add_backlog+0x4a0/0xcc0 [ 51.530286][ T7147] tcp_v4_rcv+0x1a60/0x1bb0 [ 51.534763][ T7147] ip_protocol_deliver_rcu+0x4d/0x420 [ 51.540108][ T7147] ip_local_deliver_finish+0x110/0x140 [ 51.545539][ T7147] ip_local_deliver+0x133/0x210 [ 51.550363][ T7147] ip_rcv_finish+0x121/0x160 [ 51.554929][ T7147] ip_rcv+0x18f/0x1a0 [ 51.558982][ T7147] __netif_receive_skb_one_core+0xa7/0xe0 [ 51.564679][ T7147] __netif_receive_skb+0x37/0xf0 [ 51.569592][ T7147] netif_receive_skb_internal+0x59/0x190 [ 51.575214][ T7147] napi_gro_receive+0x28f/0x330 [ 51.580039][ T7147] receive_buf+0x284/0x30b0 [ 51.584526][ T7147] virtnet_poll+0x436/0x7d0 [ 51.589014][ T7147] net_rx_action+0x3ae/0xa90 [ 51.593574][ T7147] [ 51.595911][ T7147] read to 0xffff888124e4612c of 4 bytes by task 7147 on cpu 0: [ 51.603439][ T7147] tcp_grow_window.isra.0+0x6b/0x480 [ 51.608834][ T7147] tcp_event_data_recv+0x68f/0x990 [ 51.613923][ T7147] tcp_rcv_established+0xbfe/0xf50 [ 51.619016][ T7147] tcp_v4_do_rcv+0x381/0x4e0 [ 51.623595][ T7147] __release_sock+0x135/0x1e0 [ 51.628246][ T7147] release_sock+0x61/0x160 [ 51.633083][ T7147] tcp_recvmsg+0x63b/0x1a30 [ 51.637560][ T7147] inet_recvmsg+0xbb/0x250 [ 51.641952][ T7147] sock_recvmsg+0x92/0xb0 [ 51.646256][ T7147] sock_read_iter+0x15f/0x1e0 [ 51.650910][ T7147] new_sync_read+0x389/0x4f0 [ 51.655487][ T7147] __vfs_read+0xb1/0xc0 [ 51.659614][ T7147] vfs_read+0x143/0x2c0 [ 51.663737][ T7147] [ 51.666050][ T7147] Reported by Kernel Concurrency Sanitizer on: [ 51.672191][ T7147] CPU: 0 PID: 7147 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 51.679618][ T7147] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.689658][ T7147] ================================================================== [ 51.697690][ T7147] Kernel panic - not syncing: panic_on_warn set ... [ 51.704264][ T7147] CPU: 0 PID: 7147 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 51.711690][ T7147] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.721719][ T7147] Call Trace: [ 51.725005][ T7147] dump_stack+0xf5/0x159 [ 51.729229][ T7147] panic+0x210/0x640 [ 51.733116][ T7147] ? sock_recvmsg+0x92/0xb0 [ 51.737594][ T7147] ? vprintk_func+0x8d/0x140 [ 51.742164][ T7147] kcsan_report.cold+0xc/0x10 [ 51.746821][ T7147] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 51.752345][ T7147] __tsan_read4+0x2c/0x30 [ 51.756648][ T7147] tcp_grow_window.isra.0+0x6b/0x480 [ 51.761907][ T7147] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 51.767519][ T7147] tcp_event_data_recv+0x68f/0x990 [ 51.772628][ T7147] tcp_rcv_established+0xbfe/0xf50 [ 51.777719][ T7147] ? ipv4_dst_check+0xc6/0xf0 [ 51.782388][ T7147] tcp_v4_do_rcv+0x381/0x4e0 [ 51.786965][ T7147] __release_sock+0x135/0x1e0 [ 51.791622][ T7147] release_sock+0x61/0x160 [ 51.796038][ T7147] tcp_recvmsg+0x63b/0x1a30 [ 51.800524][ T7147] inet_recvmsg+0xbb/0x250 [ 51.804935][ T7147] ? __tsan_read8+0x2c/0x30 [ 51.809427][ T7147] ? inet_sendpage+0x100/0x100 [ 51.814168][ T7147] sock_recvmsg+0x92/0xb0 [ 51.818476][ T7147] sock_read_iter+0x15f/0x1e0 [ 51.823145][ T7147] new_sync_read+0x389/0x4f0 [ 51.827728][ T7147] __vfs_read+0xb1/0xc0 [ 51.831869][ T7147] vfs_read+0x143/0x2c0 [ 51.836004][ T7147] ksys_read+0xd5/0x1b0 [ 51.840137][ T7147] __x64_sys_read+0x4c/0x60 [ 51.844617][ T7147] do_syscall_64+0xcc/0x370 [ 51.849098][ T7147] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 51.854980][ T7147] RIP: 0033:0x47c530 [ 51.858856][ T7147] 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 [ 51.878447][ T7147] RSP: 002b:000000c4202e37d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 51.886833][ T7147] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 51.894782][ T7147] RDX: 0000000000001000 RSI: 000000c420366000 RDI: 0000000000000003 [ 51.902729][ T7147] RBP: 000000c4202e3830 R08: 0000000000000000 R09: 0000000000000000 [ 51.910676][ T7147] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000010 [ 51.918625][ T7147] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 51.927918][ T7147] Kernel Offset: disabled [ 51.932253][ T7147] Rebooting in 86400 seconds..