[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.166452] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [ 20.676064] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [ 20.962916] random: sshd: uninitialized urandom read (32 bytes read, 34 bits of entropy available) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.979339] random: sshd: uninitialized urandom read (32 bytes read, 128 bits of entropy available) [ 22.047432] random: nonblocking pool is initialized Warning: Permanently added '10.128.0.29' (ECDSA) to the list of known hosts. executing program [ 27.812619] BUG: using __this_cpu_add() in preemptible [00000000] code: syzkaller287338/3774 [ 27.821232] caller is __this_cpu_preempt_check+0x1c/0x20 [ 27.826665] CPU: 0 PID: 3774 Comm: syzkaller287338 Not tainted 4.4.119-g855ea74 #27 [ 27.834426] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.843750] 0000000000000000 b0bfa9fdb6f59af1 ffff8801d93e7638 ffffffff81d0402d [ 27.851726] 0000000000000000 ffffffff839fe5a0 ffffffff83cefc20 ffff8801d9690000 [ 27.859687] 0000000000000003 ffff8801d93e7678 ffffffff81d63f84 ffff8801ccce3208 [ 27.867643] Call Trace: [ 27.870202] [] dump_stack+0xc1/0x124 [ 27.875537] [] check_preemption_disabled+0x1d4/0x200 [ 27.882258] [] __this_cpu_preempt_check+0x1c/0x20 [ 27.888720] [] tcp_try_coalesce+0x249/0x4d0 [ 27.894662] [] ? __sk_mem_schedule+0x191/0xd20 [ 27.900862] [] ? tcp_parse_options+0x970/0x970 [ 27.907059] [] ? skb_copy_datagram_from_iter+0x38c/0x5a0 [ 27.914125] [] tcp_queue_rcv+0x127/0x720 [ 27.919801] [] tcp_send_rcvq+0x39b/0x450 [ 27.925479] [] ? tcp_rcv_established+0x2230/0x2230 [ 27.932026] [] ? __local_bh_enable_ip+0x30/0xd0 [ 27.938313] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 27.945119] [] ? lock_sock_nested+0x90/0x120 [ 27.951141] [] ? trace_hardirqs_on+0xd/0x10 [ 27.957080] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 27.963364] [] tcp_sendmsg+0x1e8f/0x2b10 [ 27.969041] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.976022] [] ? sock_has_perm+0x1c1/0x400 [ 27.981874] [] ? tcp_sendpage+0x1830/0x1830 [ 27.987814] [] ? inet_sendmsg+0x201/0x4c0 [ 27.993603] [] inet_sendmsg+0x2bc/0x4c0 [ 27.999196] [] ? inet_sendmsg+0x73/0x4c0 [ 28.004874] [] ? inet_recvmsg+0x4c0/0x4c0 [ 28.010645] [] sock_sendmsg+0xca/0x110 [ 28.016147] [] sock_write_iter+0x226/0x3b0 [ 28.021997] [] ? sock_sendmsg+0x110/0x110 [ 28.027761] [] ? rw_copy_check_uvector+0x21e/0x2b0 [ 28.034305] [] do_iter_readv_writev+0x138/0x1e0 [ 28.040590] [] ? sock_sendmsg+0x110/0x110 [ 28.046354] [] ? vfs_iter_read+0x270/0x270 [ 28.052205] [] ? rw_verify_area+0x100/0x2f0 [ 28.058140] [] ? sock_sendmsg+0x110/0x110 [ 28.063905] [] do_readv_writev+0x2d2/0x6e0 [ 28.069757] [] ? vfs_write+0x530/0x530 [ 28.075264] [] ? _raw_spin_unlock+0x2c/0x50 [ 28.081202] [] ? do_huge_pmd_anonymous_page+0x3dd/0xa10 [ 28.088184] [] ? handle_mm_fault+0x3f2/0x3190 [ 28.094297] [] vfs_writev+0x7b/0xb0 [ 28.099541] [] SyS_writev+0xd9/0x240 [ 28.104874] [] ? SyS_readv+0x240/0x240 [ 28.110381] [] ? trac