[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   19.348997] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   21.106478] random: sshd: uninitialized urandom read (32 bytes read)
[   21.468527] random: sshd: uninitialized urandom read (32 bytes read)
[   22.185897] random: sshd: uninitialized urandom read (32 bytes read)
[   30.823852] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.9' (ECDSA) to the list of known hosts.
[   36.280133] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   36.371707] WARNING: CPU: 1 PID: 4511 at net/ipv4/tcp_input.c:2191 tcp_mark_head_lost+0x8e5/0xa60
[   36.380819] Kernel panic - not syncing: panic_on_warn set ...
[   36.380819] 
[   36.388176] CPU: 1 PID: 4511 Comm: syz-executor393 Not tainted 4.17.0-rc2+ #14
[   36.395512] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   36.404929] Call Trace:
[   36.407506]  dump_stack+0x1b9/0x294
[   36.411117]  ? dump_stack_print_info.cold.2+0x52/0x52
[   36.416293]  ? tcp_mark_head_lost+0x860/0xa60
[   36.420784]  panic+0x22f/0x4de
[   36.423967]  ? add_taint.cold.5+0x16/0x16
[   36.428108]  ? __warn.cold.8+0x148/0x1b3
[   36.432148]  ? __warn.cold.8+0x117/0x1b3
[   36.436192]  ? tcp_mark_head_lost+0x8e5/0xa60
[   36.440667]  __warn.cold.8+0x163/0x1b3
[   36.444537]  ? tcp_mark_head_lost+0x8e5/0xa60
[   36.449027]  report_bug+0x252/0x2d0
[   36.452670]  do_error_trap+0x1de/0x490
[   36.456538]  ? math_error+0x420/0x420
[   36.460321]  ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20
[   36.465840]  ? tcp_rate_skb_delivered+0x2d0/0x3a0
[   36.470664]  ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20
[   36.476196]  ? tcp_skb_mark_lost_uncond_verify+0x1e9/0x280
[   36.481815]  ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20
[   36.487347]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   36.492171]  do_invalid_op+0x1b/0x20
[   36.495881]  invalid_op+0x14/0x20
[   36.499319] RIP: 0010:tcp_mark_head_lost+0x8e5/0xa60
[   36.504400] RSP: 0018:ffff8801acf2f4d8 EFLAGS: 00010293
[   36.509745] RAX: ffff8801acf6c580 RBX: 0000000000000004 RCX: ffffffff8649528c
[   36.517009] RDX: 0000000000000000 RSI: ffffffff86495385 RDI: 0000000000000004
[   36.524260] RBP: ffff8801acf2f560 R08: ffff8801acf6c580 R09: ffff8801acf2f910
[   36.531520] R10: 00000000022afba7 R11: ffff88021fff8057 R12: 0000000000000003
[   36.538778] R13: ffff8801aceab500 R14: dffffc0000000000 R15: 0000000000000001
[   36.546045]  ? tcp_mark_head_lost+0x7ec/0xa60
[   36.550523]  ? tcp_mark_head_lost+0x8e5/0xa60
[   36.555007]  ? tcp_mark_head_lost+0x8e5/0xa60
[   36.559489]  ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20
[   36.565018]  tcp_fastretrans_alert+0x163c/0x2850
[   36.569761]  tcp_ack+0x2c3e/0x5500
[   36.573292]  ? tcp_fastretrans_alert+0x2850/0x2850
[   36.578217]  ? skb_scrub_packet+0x580/0x580
[   36.582526]  ? debug_check_no_locks_freed+0x310/0x310
[   36.587713]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   36.593246]  ? __sanitizer_cov_trace_const_cmp4+0x16/0x20
[   36.598773]  ? tcp_parse_options+0x1c1/0xe30
[   36.603169]  ? sched_clock_cpu+0x1b/0x180
[   36.607300]  ? __sanitizer_cov_trace_cmp4+0x20/0x20
[   36.612301]  tcp_rcv_state_process+0xc60/0x4f57
[   36.616957]  ? tcp_finish_connect+0x400/0x400
[   36.621434]  ? print_usage_bug+0xc0/0xc0
[   36.625475]  ? find_held_lock+0x36/0x1c0
[   36.629536]  ? lock_downgrade+0x8e0/0x8e0
[   36.633682]  ? __lock_is_held+0xb5/0x140
[   36.637737]  ? mark_held_locks+0xc9/0x160
[   36.641868]  ? kasan_check_read+0x11/0x20
[   36.646010]  ? __local_bh_enable_ip+0x161/0x230
[   36.650661]  tcp_v4_do_rcv+0x365/0x8c0
[   36.654540]  ? tcp_v4_do_rcv+0x365/0x8c0
[   36.658589]  __release_sock+0x12f/0x3a0
[   36.662548]  release_sock+0xa4/0x2b0
[   36.666240]  ? __release_sock+0x3a0/0x3a0
[   36.670372]  ? __local_bh_enable_ip+0x161/0x230
[   36.675023]  ? tcp_set_state+0x9b0/0x9b0
[   36.679066]  ? tcp_set_state+0x9b0/0x9b0
[   36.683111]  inet_shutdown+0x1f7/0x3d0
[   36.686981]  __sys_shutdown+0x154/0x2b0
[   36.690936]  ? __ia32_sys_getsockopt+0x150/0x150
[   36.695674]  ? __ia32_sys_fallocate+0xf0/0xf0
[   36.700156]  ? do_syscall_64+0x92/0x800
[   36.704112]  __x64_sys_shutdown+0x54/0x80
[   36.708241]  do_syscall_64+0x1b1/0x800
[   36.712111]  ? syscall_return_slowpath+0x5c0/0x5c0
[   36.717021]  ? syscall_return_slowpath+0x30f/0x5c0
[   36.721949]  ? entry_SYSCALL_64_after_hwframe+0x59/0xbe
[   36.727306]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[   36.732131]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   36.737299] RIP: 0033:0x440039
[   36.740466] RSP: 002b:00007fff5656b1b8 EFLAGS: 00000217 ORIG_RAX: 0000000000000030
[   36.748154] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440039
[   36.755404] RDX: 0000000000440039 RSI: 0000000000000001 RDI: 0000000000000003
[   36.762660] RBP: 00000000006ca018 R08: 0000000000000010 R09: 0000000000000010
[   36.769933] R10: 0000000000000009 R11: 0000000000000217 R12: 0000000000401960
[   36.777292] R13: 00000000004019f0 R14: 0000000000000000 R15: 0000000000000000
[   36.785071] Dumping ftrace buffer:
[   36.788717]    (ftrace buffer empty)
[   36.792405] Kernel Offset: disabled
[   36.796016] Rebooting in 86400 seconds..