[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   22.490959] random: sshd: uninitialized urandom read (32 bytes read, 33 bits of entropy available)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   26.025404] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available)
[   26.418653] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available)
[   26.978002] random: sshd: uninitialized urandom read (32 bytes read, 53 bits of entropy available)
[   27.139837] random: sshd: uninitialized urandom read (32 bytes read, 55 bits of entropy available)
Warning: Permanently added '10.128.0.20' (ECDSA) to the list of known hosts.
[   32.800640] random: sshd: uninitialized urandom read (32 bytes read, 61 bits of entropy available)
executing program
[   32.891159] BUG: using __this_cpu_add() in preemptible [00000000] code: syz-executor181/3794
[   32.899877] caller is __this_cpu_preempt_check+0x1c/0x20
[   32.905307] CPU: 0 PID: 3794 Comm: syz-executor181 Not tainted 4.4.151-g37af2ff #21
[   32.913088] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   32.922417]  0000000000000000 6d1674ed033f4092 ffff8801d96c7790 ffffffff81e15eed
[   32.930409]  0000000000000000 ffffffff83c154c0 ffffffff83f0d4c0 ffff8801d95c8000
[   32.938418]  0000000000000003 ffff8801d96c77d0 ffffffff81ebf7c3 ffff8801d037757c
[   32.946419] Call Trace:
[   32.948983]  [<ffffffff81e15eed>] dump_stack+0xc1/0x124
[   32.954329]  [<ffffffff81ebf7c3>] check_preemption_disabled.cold.0+0x7f/0x8b
[   32.961527]  [<ffffffff81e75bcc>] __this_cpu_preempt_check+0x1c/0x20
[   32.968027]  [<ffffffff8325d0da>] tcp_try_coalesce+0x22a/0x4c0
[   32.973991]  [<ffffffff8325ceb0>] ? tcp_parse_options+0x970/0x970
[   32.980197]  [<ffffffff83263cd7>] tcp_queue_rcv+0x127/0x6f0
[   32.985880]  [<ffffffff8327bfc6>] tcp_send_rcvq+0x3a6/0x470
[   32.991568]  [<ffffffff8327bc20>] ? tcp_rcv_established+0x1fe0/0x1fe0
[   32.998251]  [<ffffffff81140a00>] ? do_softirq.part.16+0x60/0x60
[   33.004401]  [<ffffffff8123198b>] ? trace_hardirqs_on_caller+0x38b/0x590
[   33.011227]  [<ffffffff82f2f5a0>] ? lock_sock_nested+0x90/0x120
[   33.017258]  [<ffffffff81231b9d>] ? trace_hardirqs_on+0xd/0x10
[   33.023201]  [<ffffffff81140a6a>] ? __local_bh_enable_ip+0x6a/0xd0
[   33.029495]  [<ffffffff8325365c>] tcp_sendmsg+0x23ec/0x2b10
[   33.035188]  [<ffffffff81c75f3f>] ? sock_has_perm+0x29f/0x400
[   33.041044]  [<ffffffff83251270>] ? tcp_sendpage+0x17c0/0x17c0
[   33.046991]  [<ffffffff8330a0d3>] ? inet_sendmsg+0x143/0x4d0
[   33.052762]  [<ffffffff8330a193>] inet_sendmsg+0x203/0x4d0
[   33.058377]  [<ffffffff8330a003>] ? inet_sendmsg+0x73/0x4d0
[   33.064062]  [<ffffffff83309f90>] ? inet_recvmsg+0x4c0/0x4c0
[   33.069846]  [<ffffffff82f26ddc>] sock_sendmsg+0xcc/0x110
[   33.075359]  [<ffffffff82f27abc>] SYSC_sendto+0x21c/0x370
[   33.080887]  [<ffffffff82f278a0>] ? SYSC_connect+0x300/0x300
[   33.086663]  [<ffffffff82f34506>] ? release_sock+0x3b6/0x500
[   33.092449]  [<ffffffff81140a6a>] ? __local_bh_enable_ip+0x6a/0xd0
[   33.098744]  [<ffffffff83303948>] ? inet_stream_connect+0x78/0xa0
[   33.104961]  [<ffffffff82f277ca>] ? SYSC_connect+0x22a/0x300
[   33.110736]  [<ffffffff81cb6c80>] ? selinux_netlbl_sock_rcv_skb+0x400/0x400
[   33.117814]  [<ffffffff8324d484>] ? compat_tcp_setsockopt+0x44/0x70
[   33.124202]  [<ffffffff82f2d57b>] ? compat_sock_common_setsockopt+0xbb/0x150
[   33.131362]  [<ffffffff8324d440>] ? tcp_setsockopt+0xe0/0xe0
[   33.137134]  [<ffffffff81528410>] ? fput+0x20/0x150
[