[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   20.499199] 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: [   25.681787] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available)
[   25.956688] random: sshd: uninitialized urandom read (32 bytes read, 39 bits of entropy available)
[   26.597630] random: sshd: uninitialized urandom read (32 bytes read, 62 bits of entropy available)
[   26.766803] random: sshd: uninitialized urandom read (32 bytes read, 65 bits of entropy available)
Warning: Permanently added '10.128.10.29' (ECDSA) to the list of known hosts.
[   32.346292] random: sshd: uninitialized urandom read (32 bytes read, 71 bits of entropy available)
executing program
[   32.441371] BUG: using __this_cpu_add() in preemptible [00000000] code: syz-executor322/3778
[   32.450200] caller is __this_cpu_preempt_check+0x1c/0x20
[   32.455679] CPU: 1 PID: 3778 Comm: syz-executor322 Not tainted 4.4.147-ga5fc665 #16
[   32.463553] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   32.472981]  0000000000000000 1298e5caa093da3f ffff8801da3ef790 ffffffff81e12a4d
[   32.481127]  0000000000000001 ffffffff83c153c0 ffffffff83f0d300 ffff8801cac86000
[   32.489406]  0000000000000003 ffff8801da3ef7d0 ffffffff81ebc2f3 ffff8801cf41b1bc
[   32.497451] Call Trace:
[   32.500072]  [<ffffffff81e12a4d>] dump_stack+0xc1/0x124
[   32.505516]  [<ffffffff81ebc2f3>] check_preemption_disabled.cold.0+0x7f/0x8b
[   32.512696]  [<ffffffff81e726ec>] __this_cpu_preempt_check+0x1c/0x20
[   32.519272]  [<ffffffff83259c1a>] tcp_try_coalesce+0x22a/0x4c0
[   32.525232]  [<ffffffff832599f0>] ? tcp_parse_options+0x970/0x970
[   32.531456]  [<ffffffff83260817>] tcp_queue_rcv+0x127/0x6f0
[   32.537329]  [<ffffffff83278ab6>] tcp_send_rcvq+0x3a6/0x470
[   32.543074]  [<ffffffff83278710>] ? tcp_rcv_established+0x1fe0/0x1fe0
[   32.549685]  [<ffffffff8113fc00>] ? __local_bh_enable_ip+0x40/0xd0
[   32.555994]  [<ffffffff81230b4b>] ? trace_hardirqs_on_caller+0x38b/0x590
[   32.562825]  [<ffffffff82f2c0e0>] ? lock_sock_nested+0x90/0x120
[   32.568878]  [<ffffffff81230d5d>] ? trace_hardirqs_on+0xd/0x10
[   32.574841]  [<ffffffff8113fc2a>] ? __local_bh_enable_ip+0x6a/0xd0
[   32.581150]  [<ffffffff8325019c>] tcp_sendmsg+0x23ec/0x2b10
[   32.586853]  [<ffffffff81c7287f>] ? sock_has_perm+0x29f/0x400
[   32.592728]  [<ffffffff8324ddb0>] ? tcp_sendpage+0x17c0/0x17c0
[   32.598715]  [<ffffffff83306bc3>] ? inet_sendmsg+0x143/0x4d0
[   32.604522]  [<ffffffff83306c83>] inet_sendmsg+0x203/0x4d0
[   32.610136]  [<ffffffff83306af3>] ? inet_sendmsg+0x73/0x4d0
[   32.615838]  [<ffffffff83306a80>] ? inet_recvmsg+0x4c0/0x4c0
[   32.621625]  [<ffffffff82f2391c>] sock_sendmsg+0xcc/0x110
[   32.627152]  [<ffffffff82f245fc>] SYSC_sendto+0x21c/0x370
[   32.632678]  [<ffffffff82f243e0>] ? SYSC_connect+0x300/0x300
[   32.638512]  [<ffffffff81279757>] ? debug_lockdep_rcu_enabled+0x77/0x90
[   32.645316]  [<ffffffff8157b3cf>] ? __fget_light+0x9f/0x1f0
[   32.651021]  [<ffffffff8157b538>] ? __fdget+0x18/0x20
[   32.656199]  [<ffffffff82f20846>] ? sockfd_lookup_light+0xb6/0x160
[   32.662521]  [<ffffffff83249fc4>] ? compat_tcp_setsockopt+0x44/0x70
[   32.668922]  [<ffffffff82f2a0bb>] ? compat_sock_common_setsockopt+0xbb/0x150
[   32.676099]  [<ffffffff83249f80>] ? tcp_setsockopt+0xe0/0xe0
[   32.681887]  [<ffffffff83010bc0>] ? scm_detach_fds_compat+0x3b0/0x3b0
[   32.688452]  [<ffffffff82f26c80>] SyS_sendt