[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.983556][ T25] audit: type=1800 audit(1571768962.530:25): pid=7031 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.020650][ T25] audit: type=1800 audit(1571768962.530:26): pid=7031 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.052981][ T25] audit: type=1800 audit(1571768962.540:27): pid=7031 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 '10.128.10.57' (ECDSA) to the list of known hosts. 2019/10/22 18:29:33 fuzzer started 2019/10/22 18:29:35 dialing manager at 10.128.0.105:33369 2019/10/22 18:29:35 syscalls: 2524 2019/10/22 18:29:35 code coverage: enabled 2019/10/22 18:29:35 comparison tracing: enabled 2019/10/22 18:29:35 extra coverage: extra coverage is not supported by the kernel 2019/10/22 18:29:35 setuid sandbox: enabled 2019/10/22 18:29:35 namespace sandbox: enabled 2019/10/22 18:29:35 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 18:29:35 fault injection: enabled 2019/10/22 18:29:35 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 18:29:35 net packet injection: enabled 2019/10/22 18:29:35 net device setup: enabled 2019/10/22 18:29:35 concurrency sanitizer: enabled syzkaller login: [ 47.546159][ T7193] ================================================================== [ 47.554428][ T7193] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 47.562384][ T7193] [ 47.564859][ T7193] write to 0xffff8881227b52ec of 4 bytes by interrupt on cpu 0: [ 47.572553][ T7193] tcp_add_backlog+0x4a0/0xcc0 [ 47.577590][ T7193] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.582190][ T7193] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.587551][ T7193] ip_local_deliver_finish+0x110/0x140 [ 47.592993][ T7193] ip_local_deliver+0x133/0x210 [ 47.597822][ T7193] ip_rcv_finish+0x121/0x160 [ 47.602594][ T7193] ip_rcv+0x18f/0x1a0 [ 47.606561][ T7193] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.612269][ T7193] __netif_receive_skb+0x37/0xf0 [ 47.617203][ T7193] netif_receive_skb_internal+0x59/0x190 [ 47.622824][ T7193] napi_gro_receive+0x28f/0x330 [ 47.627669][ T7193] receive_buf+0x284/0x30b0 [ 47.632150][ T7193] virtnet_poll+0x436/0x7d0 [ 47.636648][ T7193] net_rx_action+0x3ae/0xa90 [ 47.641220][ T7193] [ 47.643533][ T7193] read to 0xffff8881227b52ec of 4 bytes by task 7193 on cpu 1: [ 47.651404][ T7193] tcp_grow_window.isra.0+0x6b/0x480 [ 47.656676][ T7193] tcp_event_data_recv+0x68f/0x990 [ 47.661855][ T7193] tcp_rcv_established+0xbfe/0xf50 [ 47.666948][ T7193] tcp_v4_do_rcv+0x381/0x4e0 [ 47.671516][ T7193] __release_sock+0x135/0x1e0 [ 47.676167][ T7193] release_sock+0x61/0x160 [ 47.680570][ T7193] tcp_recvmsg+0x63b/0x1a30 [ 47.685063][ T7193] inet_recvmsg+0xbb/0x250 [ 47.689469][ T7193] sock_recvmsg+0x92/0xb0 [ 47.693788][ T7193] sock_read_iter+0x15f/0x1e0 [ 47.698443][ T7193] new_sync_read+0x389/0x4f0 [ 47.703008][ T7193] __vfs_read+0xb1/0xc0 [ 47.707163][ T7193] vfs_read+0x143/0x2c0 [ 47.711289][ T7193] [ 47.713591][ T7193] Reported by Kernel Concurrency Sanitizer on: [ 47.719722][ T7193] CPU: 1 PID: 7193 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.727153][ T7193] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.737184][ T7193] ================================================================== [ 47.745223][ T7193] Kernel panic - not syncing: panic_on_warn set ... [ 47.751789][ T7193] CPU: 1 PID: 7193 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.759229][ T7193] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.769267][ T7193] Call Trace: [ 47.772561][ T7193] dump_stack+0xf5/0x159 [ 47.776887][ T7193] panic+0x210/0x640 [ 47.780842][ T7193] ? sock_recvmsg+0x92/0xb0 [ 47.785338][ T7193] ? vprintk_func+0x8d/0x140 [ 47.789915][ T7193] kcsan_report.cold+0xc/0x10 [ 47.794573][ T7193] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.800098][ T7193] __tsan_read4+0x2c/0x30 [ 47.804449][ T7193] tcp_grow_window.isra.0+0x6b/0x480 [ 47.809768][ T7193] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.815384][ T7193] tcp_event_data_recv+0x68f/0x990 [ 47.820479][ T7193] tcp_rcv_established+0xbfe/0xf50 [ 47.825573][ T7193] ? ipv4_dst_check+0xc6/0xf0 [ 47.830234][ T7193] tcp_v4_do_rcv+0x381/0x4e0 [ 47.834813][ T7193] __release_sock+0x135/0x1e0 [ 47.839471][ T7193] release_sock+0x61/0x160 [ 47.843873][ T7193] tcp_recvmsg+0x63b/0x1a30 [ 47.848362][ T7193] inet_recvmsg+0xbb/0x250 [ 47.852769][ T7193] ? __tsan_read8+0x2c/0x30 [ 47.857951][ T7193] ? inet_sendpage+0x100/0x100 [ 47.862701][ T7193] sock_recvmsg+0x92/0xb0 [ 47.867025][ T7193] sock_read_iter+0x15f/0x1e0 [ 47.871699][ T7193] new_sync_read+0x389/0x4f0 [ 47.876274][ T7193] __vfs_read+0xb1/0xc0 [ 47.880406][ T7193] vfs_read+0x143/0x2c0 [ 47.884555][ T7193] ksys_read+0xd5/0x1b0 [ 47.888707][ T7193] __x64_sys_read+0x4c/0x60 [ 47.893207][ T7193] do_syscall_64+0xcc/0x370 [ 47.897704][ T7193] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.903588][ T7193] RIP: 0033:0x47c530 [ 47.907470][ T7193] 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 [ 47.927063][ T7193] RSP: 002b:000000c4204e97d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.935469][ T7193] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.943439][ T7193] RDX: 0000000000001000 RSI: 000000c42031c000 RDI: 0000000000000003 [ 47.951400][ T7193] RBP: 000000c4204e9830 R08: 0000000000000000 R09: 0000000000000000 [ 47.959362][ T7193] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000010 [ 47.967313][ T7193] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 47.976818][ T7193] Kernel Offset: disabled [ 47.981146][ T7193] Rebooting in 86400 seconds..