[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.193770][ T25] audit: type=1800 audit(1571746764.599:25): pid=7056 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 38.214544][ T25] audit: type=1800 audit(1571746764.609:26): pid=7056 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 38.214559][ T25] audit: type=1800 audit(1571746764.609:27): pid=7056 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 '10.128.0.93' (ECDSA) to the list of known hosts. 2019/10/22 12:19:36 fuzzer started 2019/10/22 12:19:38 dialing manager at 10.128.0.105:37053 2019/10/22 12:19:38 syscalls: 2524 2019/10/22 12:19:38 code coverage: enabled 2019/10/22 12:19:38 comparison tracing: enabled 2019/10/22 12:19:38 extra coverage: extra coverage is not supported by the kernel 2019/10/22 12:19:38 setuid sandbox: enabled 2019/10/22 12:19:38 namespace sandbox: enabled 2019/10/22 12:19:38 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 12:19:38 fault injection: enabled 2019/10/22 12:19:38 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 12:19:38 net packet injection: enabled 2019/10/22 12:19:38 net device setup: enabled 2019/10/22 12:19:38 concurrency sanitizer: enabled syzkaller login: [ 52.391054][ T7209] ================================================================== [ 52.399211][ T7209] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 52.406222][ T7209] [ 52.408542][ T7209] write to 0xffff888126474138 of 8 bytes by interrupt on cpu 1: [ 52.416310][ T7209] tcp_add_backlog+0x45a/0xcc0 [ 52.421171][ T7209] tcp_v4_rcv+0x1a60/0x1bb0 [ 52.425660][ T7209] ip_protocol_deliver_rcu+0x4d/0x420 [ 52.431019][ T7209] ip_local_deliver_finish+0x110/0x140 [ 52.436523][ T7209] ip_local_deliver+0x133/0x210 [ 52.441357][ T7209] ip_rcv_finish+0x121/0x160 [ 52.446045][ T7209] ip_rcv+0x18f/0x1a0 [ 52.450016][ T7209] __netif_receive_skb_one_core+0xa7/0xe0 [ 52.455720][ T7209] __netif_receive_skb+0x37/0xf0 [ 52.460807][ T7209] netif_receive_skb_internal+0x59/0x190 [ 52.466557][ T7209] napi_gro_receive+0x28f/0x330 [ 52.471436][ T7209] receive_buf+0x284/0x30b0 [ 52.475922][ T7209] virtnet_poll+0x436/0x7d0 [ 52.480563][ T7209] net_rx_action+0x3ae/0xa90 [ 52.485140][ T7209] [ 52.487594][ T7209] read to 0xffff888126474138 of 8 bytes by task 7209 on cpu 0: [ 52.495133][ T7209] tcp_recvmsg+0x470/0x1a30 [ 52.499622][ T7209] inet_recvmsg+0xbb/0x250 [ 52.504026][ T7209] sock_recvmsg+0x92/0xb0 [ 52.508437][ T7209] sock_read_iter+0x15f/0x1e0 [ 52.513294][ T7209] new_sync_read+0x389/0x4f0 [ 52.517910][ T7209] __vfs_read+0xb1/0xc0 [ 52.522060][ T7209] vfs_read+0x143/0x2c0 [ 52.526215][ T7209] ksys_read+0xd5/0x1b0 [ 52.530353][ T7209] __x64_sys_read+0x4c/0x60 [ 52.534957][ T7209] do_syscall_64+0xcc/0x370 [ 52.539480][ T7209] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.545370][ T7209] [ 52.547680][ T7209] Reported by Kernel Concurrency Sanitizer on: [ 52.554018][ T7209] CPU: 0 PID: 7209 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 52.561531][ T7209] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.571705][ T7209] ================================================================== [ 52.579806][ T7209] Kernel panic - not syncing: panic_on_warn set ... [ 52.586402][ T7209] CPU: 0 PID: 7209 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 52.594138][ T7209] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.604435][ T7209] Call Trace: [ 52.607732][ T7209] dump_stack+0xf5/0x159 [ 52.612092][ T7209] panic+0x210/0x640 [ 52.615978][ T7209] ? __x64_sys_read+0x4c/0x60 [ 52.620677][ T7209] ? vprintk_func+0x8d/0x140 [ 52.625360][ T7209] kcsan_report.cold+0xc/0x10 [ 52.630026][ T7209] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 52.635558][ T7209] __tsan_read8+0x2c/0x30 [ 52.639884][ T7209] tcp_recvmsg+0x470/0x1a30 [ 52.644379][ T7209] ? debug_smp_processor_id+0x4c/0x172 [ 52.649857][ T7209] inet_recvmsg+0xbb/0x250 [ 52.654350][ T7209] ? __tsan_read8+0x2c/0x30 [ 52.658883][ T7209] ? inet_sendpage+0x100/0x100 [ 52.664154][ T7209] sock_recvmsg+0x92/0xb0 [ 52.668593][ T7209] sock_read_iter+0x15f/0x1e0 [ 52.673506][ T7209] new_sync_read+0x389/0x4f0 [ 52.678213][ T7209] __vfs_read+0xb1/0xc0 [ 52.682445][ T7209] vfs_read+0x143/0x2c0 [ 52.686860][ T7209] ksys_read+0xd5/0x1b0 [ 52.691015][ T7209] __x64_sys_read+0x4c/0x60 [ 52.695519][ T7209] do_syscall_64+0xcc/0x370 [ 52.700018][ T7209] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.705900][ T7209] RIP: 0033:0x47c530 [ 52.709784][ T7209] 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 [ 52.729588][ T7209] RSP: 002b:000000c4203c17d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 52.738259][ T7209] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 52.746224][ T7209] RDX: 0000000000001000 RSI: 000000c4203a4000 RDI: 0000000000000003 [ 52.754271][ T7209] RBP: 000000c4203c1830 R08: 0000000000000000 R09: 0000000000000000 [ 52.762228][ T7209] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000008 [ 52.770189][ T7209] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 52.779930][ T7209] Kernel Offset: disabled [ 52.784267][ T7209] Rebooting in 86400 seconds..