[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.874140][ T26] audit: type=1800 audit(1571765418.354:25): pid=6974 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 33.893781][ T26] audit: type=1800 audit(1571765418.354:26): pid=6974 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 33.914759][ T26] audit: type=1800 audit(1571765418.354:27): pid=6974 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 '10.128.0.143' (ECDSA) to the list of known hosts. 2019/10/22 17:30:31 fuzzer started 2019/10/22 17:30:32 dialing manager at 10.128.0.105:33369 2019/10/22 17:30:32 syscalls: 2524 2019/10/22 17:30:32 code coverage: enabled 2019/10/22 17:30:32 comparison tracing: enabled 2019/10/22 17:30:32 extra coverage: extra coverage is not supported by the kernel 2019/10/22 17:30:32 setuid sandbox: enabled 2019/10/22 17:30:32 namespace sandbox: enabled 2019/10/22 17:30:32 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 17:30:32 fault injection: enabled 2019/10/22 17:30:32 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 17:30:32 net packet injection: enabled 2019/10/22 17:30:32 net device setup: enabled 2019/10/22 17:30:32 concurrency sanitizer: enabled syzkaller login: [ 48.253636][ T7127] ================================================================== [ 48.261767][ T7127] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 48.269724][ T7127] [ 48.272172][ T7127] write to 0xffff888123b472ec of 4 bytes by interrupt on cpu 1: [ 48.279778][ T7127] tcp_add_backlog+0x4a0/0xcc0 [ 48.284515][ T7127] tcp_v4_rcv+0x1a60/0x1bb0 [ 48.288993][ T7127] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.294336][ T7127] ip_local_deliver_finish+0x110/0x140 [ 48.299766][ T7127] ip_local_deliver+0x133/0x210 [ 48.304589][ T7127] ip_rcv_finish+0x121/0x160 [ 48.309153][ T7127] ip_rcv+0x18f/0x1a0 [ 48.313110][ T7127] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.318847][ T7127] __netif_receive_skb+0x37/0xf0 [ 48.323796][ T7127] netif_receive_skb_internal+0x59/0x190 [ 48.329422][ T7127] napi_gro_receive+0x28f/0x330 [ 48.334248][ T7127] receive_buf+0x284/0x30b0 [ 48.338725][ T7127] virtnet_poll+0x436/0x7d0 [ 48.343220][ T7127] net_rx_action+0x3ae/0xa90 [ 48.347777][ T7127] [ 48.350090][ T7127] read to 0xffff888123b472ec of 4 bytes by task 7127 on cpu 0: [ 48.357605][ T7127] tcp_grow_window.isra.0+0x6b/0x480 [ 48.362862][ T7127] tcp_event_data_recv+0x68f/0x990 [ 48.367956][ T7127] tcp_rcv_established+0xbfe/0xf50 [ 48.373041][ T7127] tcp_v4_do_rcv+0x381/0x4e0 [ 48.377617][ T7127] __release_sock+0x135/0x1e0 [ 48.382268][ T7127] release_sock+0x61/0x160 [ 48.386657][ T7127] tcp_recvmsg+0x63b/0x1a30 [ 48.391146][ T7127] inet_recvmsg+0xbb/0x250 [ 48.395537][ T7127] sock_recvmsg+0x92/0xb0 [ 48.399841][ T7127] sock_read_iter+0x15f/0x1e0 [ 48.404513][ T7127] new_sync_read+0x389/0x4f0 [ 48.409077][ T7127] __vfs_read+0xb1/0xc0 [ 48.413206][ T7127] vfs_read+0x143/0x2c0 [ 48.417345][ T7127] [ 48.419667][ T7127] Reported by Kernel Concurrency Sanitizer on: [ 48.425795][ T7127] CPU: 0 PID: 7127 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.433228][ T7127] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.443272][ T7127] ================================================================== [ 48.451307][ T7127] Kernel panic - not syncing: panic_on_warn set ... [ 48.457868][ T7127] CPU: 0 PID: 7127 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.465292][ T7127] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.475328][ T7127] Call Trace: [ 48.478600][ T7127] dump_stack+0xf5/0x159 [ 48.482828][ T7127] panic+0x210/0x640 [ 48.486710][ T7127] ? sock_recvmsg+0x92/0xb0 [ 48.491190][ T7127] ? vprintk_func+0x8d/0x140 [ 48.495766][ T7127] kcsan_report.cold+0xc/0x10 [ 48.500420][ T7127] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.505943][ T7127] __tsan_read4+0x2c/0x30 [ 48.510264][ T7127] tcp_grow_window.isra.0+0x6b/0x480 [ 48.515541][ T7127] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.521167][ T7127] tcp_event_data_recv+0x68f/0x990 [ 48.526279][ T7127] tcp_rcv_established+0xbfe/0xf50 [ 48.531373][ T7127] ? ipv4_dst_check+0xc6/0xf0 [ 48.536031][ T7127] tcp_v4_do_rcv+0x381/0x4e0 [ 48.540605][ T7127] __release_sock+0x135/0x1e0 [ 48.545266][ T7127] release_sock+0x61/0x160 [ 48.549662][ T7127] tcp_recvmsg+0x63b/0x1a30 [ 48.554172][ T7127] inet_recvmsg+0xbb/0x250 [ 48.558566][ T7127] ? __tsan_read8+0x2c/0x30 [ 48.563045][ T7127] ? inet_sendpage+0x100/0x100 [ 48.567787][ T7127] sock_recvmsg+0x92/0xb0 [ 48.572095][ T7127] sock_read_iter+0x15f/0x1e0 [ 48.576762][ T7127] new_sync_read+0x389/0x4f0 [ 48.581339][ T7127] __vfs_read+0xb1/0xc0 [ 48.585470][ T7127] vfs_read+0x143/0x2c0 [ 48.589605][ T7127] ksys_read+0xd5/0x1b0 [ 48.593913][ T7127] __x64_sys_read+0x4c/0x60 [ 48.598397][ T7127] do_syscall_64+0xcc/0x370 [ 48.602876][ T7127] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.608753][ T7127] RIP: 0033:0x47c530 [ 48.612628][ T7127] 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 [ 48.632477][ T7127] RSP: 002b:000000c4204f1810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 48.640871][ T7127] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.649425][ T7127] RDX: 0000000000001000 RSI: 000000c4203cc000 RDI: 0000000000000003 [ 48.657382][ T7127] RBP: 000000c4204f1868 R08: 0000000000000000 R09: 0000000000000000 [ 48.665330][ T7127] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 [ 48.673276][ T7127] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 48.682414][ T7127] Kernel Offset: disabled [ 48.686733][ T7127] Rebooting in 86400 seconds..