[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.937549][ T25] audit: type=1800 audit(1571774185.782:25): pid=7081 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.964493][ T25] audit: type=1800 audit(1571774185.782:26): pid=7081 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 37.003325][ T25] audit: type=1800 audit(1571774185.782:27): pid=7081 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 '10.128.1.24' (ECDSA) to the list of known hosts. 2019/10/22 19:56:35 fuzzer started 2019/10/22 19:56:36 dialing manager at 10.128.0.105:33369 2019/10/22 19:56:36 syscalls: 2524 2019/10/22 19:56:36 code coverage: enabled 2019/10/22 19:56:36 comparison tracing: enabled 2019/10/22 19:56:36 extra coverage: extra coverage is not supported by the kernel 2019/10/22 19:56:36 setuid sandbox: enabled 2019/10/22 19:56:36 namespace sandbox: enabled 2019/10/22 19:56:36 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 19:56:36 fault injection: enabled 2019/10/22 19:56:36 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 19:56:36 net packet injection: enabled 2019/10/22 19:56:36 net device setup: enabled 2019/10/22 19:56:36 concurrency sanitizer: enabled syzkaller login: [ 48.207750][ T7235] ================================================================== [ 48.215887][ T7235] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 48.223850][ T7235] [ 48.226167][ T7235] write to 0xffff888126b389ec of 4 bytes by interrupt on cpu 0: [ 48.233774][ T7235] tcp_add_backlog+0x4a0/0xcc0 [ 48.238513][ T7235] tcp_v4_rcv+0x1a60/0x1bb0 [ 48.242992][ T7235] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.248340][ T7235] ip_local_deliver_finish+0x110/0x140 [ 48.253773][ T7235] ip_local_deliver+0x133/0x210 [ 48.258608][ T7235] ip_rcv_finish+0x121/0x160 [ 48.263255][ T7235] ip_rcv+0x18f/0x1a0 [ 48.267221][ T7235] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.272917][ T7235] __netif_receive_skb+0x37/0xf0 [ 48.277845][ T7235] netif_receive_skb_internal+0x59/0x190 [ 48.283457][ T7235] napi_gro_receive+0x28f/0x330 [ 48.288287][ T7235] receive_buf+0x284/0x30b0 [ 48.292765][ T7235] virtnet_poll+0x436/0x7d0 [ 48.297244][ T7235] net_rx_action+0x3ae/0xa90 [ 48.301801][ T7235] [ 48.304109][ T7235] read to 0xffff888126b389ec of 4 bytes by task 7235 on cpu 1: [ 48.311627][ T7235] tcp_grow_window.isra.0+0x6b/0x480 [ 48.316932][ T7235] tcp_event_data_recv+0x68f/0x990 [ 48.322204][ T7235] tcp_rcv_established+0xbfe/0xf50 [ 48.327297][ T7235] tcp_v4_do_rcv+0x381/0x4e0 [ 48.331865][ T7235] __release_sock+0x135/0x1e0 [ 48.336518][ T7235] release_sock+0x61/0x160 [ 48.340911][ T7235] tcp_recvmsg+0x63b/0x1a30 [ 48.345389][ T7235] inet_recvmsg+0xbb/0x250 [ 48.349783][ T7235] sock_recvmsg+0x92/0xb0 [ 48.354135][ T7235] sock_read_iter+0x15f/0x1e0 [ 48.358786][ T7235] new_sync_read+0x389/0x4f0 [ 48.363353][ T7235] __vfs_read+0xb1/0xc0 [ 48.367481][ T7235] vfs_read+0x143/0x2c0 [ 48.371603][ T7235] [ 48.373902][ T7235] Reported by Kernel Concurrency Sanitizer on: [ 48.380032][ T7235] CPU: 1 PID: 7235 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.388500][ T7235] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.398576][ T7235] ================================================================== [ 48.406612][ T7235] Kernel panic - not syncing: panic_on_warn set ... [ 48.413176][ T7235] CPU: 1 PID: 7235 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.420635][ T7235] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.430660][ T7235] Call Trace: [ 48.433936][ T7235] dump_stack+0xf5/0x159 [ 48.438159][ T7235] panic+0x210/0x640 [ 48.442041][ T7235] ? sock_recvmsg+0x92/0xb0 [ 48.446525][ T7235] ? vprintk_func+0x8d/0x140 [ 48.451095][ T7235] kcsan_report.cold+0xc/0x10 [ 48.455791][ T7235] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.461314][ T7235] __tsan_read4+0x2c/0x30 [ 48.465619][ T7235] tcp_grow_window.isra.0+0x6b/0x480 [ 48.470878][ T7235] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.476531][ T7235] tcp_event_data_recv+0x68f/0x990 [ 48.481708][ T7235] tcp_rcv_established+0xbfe/0xf50 [ 48.486800][ T7235] ? ipv4_dst_check+0xc6/0xf0 [ 48.491463][ T7235] tcp_v4_do_rcv+0x381/0x4e0 [ 48.496030][ T7235] __release_sock+0x135/0x1e0 [ 48.500683][ T7235] release_sock+0x61/0x160 [ 48.505086][ T7235] tcp_recvmsg+0x63b/0x1a30 [ 48.509576][ T7235] inet_recvmsg+0xbb/0x250 [ 48.513988][ T7235] ? __tsan_read8+0x2c/0x30 [ 48.518468][ T7235] ? inet_sendpage+0x100/0x100 [ 48.523207][ T7235] sock_recvmsg+0x92/0xb0 [ 48.527525][ T7235] sock_read_iter+0x15f/0x1e0 [ 48.532198][ T7235] new_sync_read+0x389/0x4f0 [ 48.536788][ T7235] __vfs_read+0xb1/0xc0 [ 48.540930][ T7235] vfs_read+0x143/0x2c0 [ 48.545062][ T7235] ksys_read+0xd5/0x1b0 [ 48.550413][ T7235] __x64_sys_read+0x4c/0x60 [ 48.554893][ T7235] do_syscall_64+0xcc/0x370 [ 48.559377][ T7235] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.565253][ T7235] RIP: 0033:0x47c530 [ 48.569213][ T7235] 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 [ 48.588799][ T7235] RSP: 002b:000000c4204eb810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 48.597186][ T7235] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.605133][ T7235] RDX: 0000000000001000 RSI: 000000c4203d6000 RDI: 0000000000000003 [ 48.613081][ T7235] RBP: 000000c4204eb868 R08: 0000000000000000 R09: 0000000000000000 [ 48.621030][ T7235] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 [ 48.628977][ T7235] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 48.638171][ T7235] Kernel Offset: disabled [ 48.642486][ T7235] Rebooting in 86400 seconds..