[ 21.371317] random: sshd: uninitialized urandom read (32 bytes read, 34 bits of entropy available) [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.884445] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 25.394423] random: sshd: uninitialized urandom read (32 bytes read, 38 bits of entropy available) [ 26.386215] random: sshd: uninitialized urandom read (32 bytes read, 107 bits of entropy available) [ 26.567685] random: sshd: uninitialized urandom read (32 bytes read, 112 bits of entropy available) Warning: Permanently added '10.128.0.32' (ECDSA) to the list of known hosts. [ 31.993065] random: sshd: uninitialized urandom read (32 bytes read, 118 bits of entropy available) executing program [ 32.092686] BUG: using __this_cpu_add() in preemptible [00000000] code: syzkaller639937/3656 [ 32.101315] caller is __this_cpu_preempt_check+0x1c/0x20 [ 32.106748] CPU: 0 PID: 3656 Comm: syzkaller639937 Not tainted 4.4.119-g024f962 #26 [ 32.114508] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.123831] 0000000000000000 57c575a705652923 ffff8801d25af638 ffffffff81d0402d [ 32.131801] 0000000000000000 ffffffff839fe5a0 ffffffff83cefc20 ffff8801cd1f6000 [ 32.139770] 0000000000000003 ffff8801d25af678 ffffffff81d63f84 ffff8801cb6cbd48 [ 32.147740] Call Trace: [ 32.150302] [] dump_stack+0xc1/0x124 [ 32.155635] [] check_preemption_disabled+0x1d4/0x200 [ 32.162358] [] __this_cpu_preempt_check+0x1c/0x20 [ 32.168821] [] tcp_try_coalesce+0x249/0x4d0 [ 32.174764] [] ? __sk_mem_schedule+0x191/0xd20 [ 32.180965] [] ? tcp_parse_options+0x970/0x970 [ 32.187168] [] ? skb_copy_datagram_from_iter+0x38c/0x5a0 [ 32.194247] [] tcp_queue_rcv+0x127/0x720 [ 32.199926] [] tcp_send_rcvq+0x39b/0x450 [ 32.205604] [] ? tcp_rcv_established+0x2230/0x2230 [ 32.212155] [] ? __local_bh_enable_ip+0x30/0xd0 [ 32.218444] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 32.225264] [] ? lock_sock_nested+0x90/0x120 [ 32.231290] [] ? trace_hardirqs_on+0xd/0x10 [ 32.237231] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 32.243518] [] tcp_sendmsg+0x1e8f/0x2b10 [ 32.249198] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 32.256183] [] ? sock_has_perm+0x1c1/0x400 [ 32.262039] [] ? tcp_sendpage+0x1830/0x1830 [ 32.267981] [] ? inet_sendmsg+0x201/0x4c0 [ 32.273750] [] inet_sendmsg+0x2bc/0x4c0 [ 32.279359] [] ? inet_sendmsg+0x73/0x4c0 [ 32.285039] [] ? inet_recvmsg+0x4c0/0x4c0 [ 32.290806] [] sock_sendmsg+0xca/0x110 [ 32.296311] [] sock_write_iter+0x226/0x3b0 [ 32.302166] [] ? sock_sendmsg+0x110/0x110 [ 32.307944] [] ? rw_copy_check_uvector+0x21e/0x2b0 [ 32.314580] [] do_iter_readv_writev+0x138/0x1e0 [ 32.320879] [] ? sock_sendmsg+0x110/0x110 [ 32.326818] [] ? vfs_iter_read+0x270/0x270 [ 32.332670] [] ? rw_verify_area+0x100/0x2f0 [ 32.338613] [] ? sock_sendmsg+0x110/0x110 [ 32.344381] [] do_readv_writev+0x2d2/0x6e0 [ 32.350232] [] ? vfs_write+0x530/0x530 [ 32.355747] [] ? _raw_spin_unlock+0x2c/0x50 [ 32.361687] [] ? do_huge_pmd_anonymous_page+0x3dd/0xa10 [ 32.368673] [] ? handle_mm_fault+0x3f2/0x3190 [ 32.374785] [] vfs_writev+0x7b/0xb0 [ 32.380028] [] SyS_writev+0xd9/0x240 [ 32.385359] [] ? SyS_readv+0x240/0x240 [ 32.390972] []