[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.231728][ T25] audit: type=1800 audit(1571785419.189:25): pid=6927 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 38.251508][ T25] audit: type=1800 audit(1571785419.189:26): pid=6927 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 38.273205][ T25] audit: type=1800 audit(1571785419.189:27): pid=6927 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 '10.128.10.35' (ECDSA) to the list of known hosts. 2019/10/22 23:03:49 fuzzer started 2019/10/22 23:03:51 dialing manager at 10.128.0.105:33369 2019/10/22 23:03:51 syscalls: 2524 2019/10/22 23:03:51 code coverage: enabled 2019/10/22 23:03:51 comparison tracing: enabled 2019/10/22 23:03:51 extra coverage: extra coverage is not supported by the kernel 2019/10/22 23:03:51 setuid sandbox: enabled 2019/10/22 23:03:51 namespace sandbox: enabled 2019/10/22 23:03:51 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 23:03:51 fault injection: enabled 2019/10/22 23:03:51 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 23:03:51 net packet injection: enabled 2019/10/22 23:03:51 net device setup: enabled 2019/10/22 23:03:51 concurrency sanitizer: enabled syzkaller login: [ 50.219923][ T7082] ================================================================== [ 50.228059][ T7082] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 50.236007][ T7082] [ 50.238313][ T7082] write to 0xffff888126b3c9ec of 4 bytes by interrupt on cpu 0: [ 50.247222][ T7082] tcp_add_backlog+0x4a0/0xcc0 [ 50.251962][ T7082] tcp_v4_rcv+0x1a60/0x1bb0 [ 50.256443][ T7082] ip_protocol_deliver_rcu+0x4d/0x420 [ 50.261834][ T7082] ip_local_deliver_finish+0x110/0x140 [ 50.267267][ T7082] ip_local_deliver+0x133/0x210 [ 50.272093][ T7082] ip_rcv_finish+0x121/0x160 [ 50.276745][ T7082] ip_rcv+0x18f/0x1a0 [ 50.280708][ T7082] __netif_receive_skb_one_core+0xa7/0xe0 [ 50.286398][ T7082] __netif_receive_skb+0x37/0xf0 [ 50.291309][ T7082] netif_receive_skb_internal+0x59/0x190 [ 50.296992][ T7082] napi_gro_receive+0x28f/0x330 [ 50.301822][ T7082] receive_buf+0x284/0x30b0 [ 50.306299][ T7082] virtnet_poll+0x436/0x7d0 [ 50.310916][ T7082] net_rx_action+0x3ae/0xa90 [ 50.315497][ T7082] [ 50.317805][ T7082] read to 0xffff888126b3c9ec of 4 bytes by task 7082 on cpu 1: [ 50.325325][ T7082] tcp_grow_window.isra.0+0x6b/0x480 [ 50.330588][ T7082] tcp_event_data_recv+0x68f/0x990 [ 50.335684][ T7082] tcp_rcv_established+0xbfe/0xf50 [ 50.340866][ T7082] tcp_v4_do_rcv+0x381/0x4e0 [ 50.345446][ T7082] __release_sock+0x135/0x1e0 [ 50.350105][ T7082] release_sock+0x61/0x160 [ 50.354499][ T7082] tcp_recvmsg+0x63b/0x1a30 [ 50.358978][ T7082] inet_recvmsg+0xbb/0x250 [ 50.363372][ T7082] sock_recvmsg+0x92/0xb0 [ 50.367674][ T7082] sock_read_iter+0x15f/0x1e0 [ 50.372339][ T7082] new_sync_read+0x389/0x4f0 [ 50.376903][ T7082] __vfs_read+0xb1/0xc0 [ 50.381033][ T7082] vfs_read+0x143/0x2c0 [ 50.385157][ T7082] [ 50.387459][ T7082] Reported by Kernel Concurrency Sanitizer on: [ 50.393587][ T7082] CPU: 1 PID: 7082 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.401012][ T7082] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.411070][ T7082] ================================================================== [ 50.419104][ T7082] Kernel panic - not syncing: panic_on_warn set ... [ 50.425668][ T7082] CPU: 1 PID: 7082 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.433097][ T7082] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.443125][ T7082] Call Trace: [ 50.446395][ T7082] dump_stack+0xf5/0x159 [ 50.450630][ T7082] panic+0x210/0x640 [ 50.454516][ T7082] ? sock_recvmsg+0x92/0xb0 [ 50.458996][ T7082] ? vprintk_func+0x8d/0x140 [ 50.463563][ T7082] kcsan_report.cold+0xc/0x10 [ 50.468218][ T7082] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 50.473740][ T7082] __tsan_read4+0x2c/0x30 [ 50.478086][ T7082] tcp_grow_window.isra.0+0x6b/0x480 [ 50.483443][ T7082] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 50.489088][ T7082] tcp_event_data_recv+0x68f/0x990 [ 50.494266][ T7082] tcp_rcv_established+0xbfe/0xf50 [ 50.499359][ T7082] ? ipv4_dst_check+0xc6/0xf0 [ 50.504015][ T7082] tcp_v4_do_rcv+0x381/0x4e0 [ 50.508580][ T7082] __release_sock+0x135/0x1e0 [ 50.513234][ T7082] release_sock+0x61/0x160 [ 50.517631][ T7082] tcp_recvmsg+0x63b/0x1a30 [ 50.522118][ T7082] inet_recvmsg+0xbb/0x250 [ 50.526508][ T7082] ? __tsan_read8+0x2c/0x30 [ 50.533712][ T7082] ? inet_sendpage+0x100/0x100 [ 50.538451][ T7082] sock_recvmsg+0x92/0xb0 [ 50.542759][ T7082] sock_read_iter+0x15f/0x1e0 [ 50.547509][ T7082] new_sync_read+0x389/0x4f0 [ 50.552078][ T7082] __vfs_read+0xb1/0xc0 [ 50.556210][ T7082] vfs_read+0x143/0x2c0 [ 50.560379][ T7082] ksys_read+0xd5/0x1b0 [ 50.564514][ T7082] __x64_sys_read+0x4c/0x60 [ 50.568994][ T7082] do_syscall_64+0xcc/0x370 [ 50.573488][ T7082] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.579363][ T7082] RIP: 0033:0x47c530 [ 50.583245][ T7082] 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 [ 50.602821][ T7082] RSP: 002b:000000c42030f7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 50.611216][ T7082] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 50.619181][ T7082] RDX: 0000000000001000 RSI: 000000c4203e2000 RDI: 0000000000000003 [ 50.627224][ T7082] RBP: 000000c42030f830 R08: 0000000000000000 R09: 0000000000000000 [ 50.635168][ T7082] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000004 [ 50.643113][ T7082] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 50.652457][ T7082] Kernel Offset: disabled [ 50.656778][ T7082] Rebooting in 86400 seconds..