[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.558483] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.181999] random: sshd: uninitialized urandom read (32 bytes read) [ 24.491748] random: sshd: uninitialized urandom read (32 bytes read) [ 25.243131] random: sshd: uninitialized urandom read (32 bytes read) [ 25.399642] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.55' (ECDSA) to the list of known hosts. [ 30.847902] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 30.993588] kasan: CONFIG_KASAN_INLINE enabled [ 30.998511] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 31.005944] general protection fault: 0000 [#1] SMP KASAN [ 31.011477] Dumping ftrace buffer: [ 31.015010] (ftrace buffer empty) [ 31.018725] Modules linked in: [ 31.021922] CPU: 1 PID: 4530 Comm: syz-executor147 Not tainted 4.17.0-rc5+ #54 [ 31.029277] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 31.038646] RIP: 0010:n_tty_flush_buffer+0x64/0x320 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 31.043657] RSP: 0018:ffff8801c60f77a0 EFLAGS: 00010202 [ 31.049023] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 31.056296] RDX: 000000000000044c RSI: ffff8801ae012ef8 RDI: 0000000000002260 [ 31.063652] RBP: ffff8801c60f77b8 R08: 0000000000007ad5 R09: 0000000000000002 [ 31.070922] R10: ffff8801ae012f48 R11: ffff8801ae0126c0 R12: ffff8801d96321c0 [ 31.078195] R13: ffff8801d96323f8 R14: 0000000000000000 R15: ffff8801c60f7808 [ 31.085469] FS: 00007f53b10c8700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 31.093692] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 31.099574] CR2: 00007f53b10a6e78 CR3: 00000001ac8cf000 CR4: 00000000001406e0 [ 31.106847] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 31.114117] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 31.121384] Call Trace: [ 31.123976] set_termios+0x390/0x7d0 [ 31.127694] ? n_tty_poll+0xa80/0xa80 [ 31.131504] ? tty_perform_flush+0x80/0x80 [ 31.135753] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 31.141297] tty_mode_ioctl+0x265/0xb50 [ 31.145281] ? set_termios+0x7d0/0x7d0 [ 31.149181] ? check_same_owner+0x320/0x320 [ 31.153502] ? exit_robust_list+0x290/0x290 [ 31.157828] n_tty_ioctl_helper+0x54/0x3b0 [ 31.162063] n_tty_ioctl+0x54/0x320 [ 31.165671] ? ldsem_down_read+0x37/0x40 [ 31.169710] ? ldsem_down_read+0x37/0x40 [ 31.173756] tty_ioctl+0x5e1/0x1870 [ 31.177367] ? commit_echoes+0x1d0/0x1d0 [ 31.181408] ? tty_vhangup+0x30/0x30 [ 31.185097] ? rcu_is_watching+0x85/0x140 [ 31.189238] ? rcu_bh_force_quiescent_state+0x20/0x20 executing program executing program executing program executing program executing program executing program executing program [ 31.194422] ? __fget+0x40c/0x650 [ 31.197866] ? expand_files.part.8+0x9a0/0x9a0 [ 31.202435] ? trace_hardirqs_off+0xd/0x10 [ 31.206653] ? _raw_spin_unlock_irqrestore+0x63/0xc0 [ 31.211741] ? tty_vhangup+0x30/0x30 [ 31.215440] do_vfs_ioctl+0x1cf/0x16a0 [ 31.219308] ? rcu_pm_notify+0xc0/0xc0 [ 31.223179] ? trace_hardirqs_off+0xd/0x10 [ 31.227416] ? ioctl_preallocate+0x2e0/0x2e0 [ 31.231824] ? fget_raw+0x20/0x20 [ 31.235271] ? kmem_cache_free+0x25c/0x2d0 [ 31.239492] ? __x64_sys_futex+0x477/0x680 executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 31.243709] ? do_futex+0x27d0/0x27d0 [ 31.247509] ? security_file_ioctl+0x94/0xc0 [ 31.251912] ksys_ioctl+0xa9/0xd0 [ 31.255348] __x64_sys_ioctl+0x73/0xb0 [ 31.259217] do_syscall_64+0x1b1/0x800 [ 31.263090] ? finish_task_switch+0x1ca/0x840 [ 31.267574] ? syscall_return_slowpath+0x5c0/0x5c0 [ 31.272485] ? syscall_return_slowpath+0x30f/0x5c0 [ 31.277398] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 31.282745] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 31.287575] entry_SYSCALL_64_after_hwframe+0x49/0xbe executing program executing program executing program [ 31.292743] RIP: 0033:0x445c19 [ 31.295909] RSP: 002b:00007f53b10c7da8 EFLAGS: 00000297 ORIG_RAX: 0000000000000010 [ 31.303597] RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 0000000000445c19 [ 31.310847] RDX: 0000000020000000 RSI: 0000000000005404 RDI: 0000000000000005 [ 31.318095] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 31.325345] R10: 0000000000000000 R11: 0000000000000297 R12: 00000000006dac20 [ 31.332601] R13: 6d74702f7665642f R14: 00007f53b10c89c0 R15: 0000000000000007 executing program executing program executing program [ 31.339856] Code: 03 80 3c 02 00 0f 85 b1 02 00 00 49 8b 9c 24 70 05 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bb 60 22 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 9b 02 00 00 48 b8 00 00 00 00 00 fc ff df 48 [ 31.359027] RIP: n_tty_flush_buffer+0x64/0x320 RSP: ffff8801c60f77a0 [ 31.365660] ---[ end trace 75cd8a017cb978de ]--- [ 31.370429] Kernel panic - not syncing: Fatal exception [ 31.376228] Dumping ftrace buffer: [ 31.379750] (ftrace buffer empty) [ 31.383437] Kernel Offset: disabled [ 31.387042] Rebooting in 86400 seconds..