[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   31.874624] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   36.880999] random: sshd: uninitialized urandom read (32 bytes read)
[   37.434673] random: sshd: uninitialized urandom read (32 bytes read)
[   38.638753] random: sshd: uninitialized urandom read (32 bytes read)
[   38.855727] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.0.63' (ECDSA) to the list of known hosts.
[   44.360224] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   44.478978] ==================================================================
[   44.486467] BUG: KMSAN: kernel-infoleak in copy_from_read_buf+0x311/0x890
[   44.493485] CPU: 0 PID: 4519 Comm: syz-executor294 Not tainted 4.17.0+ #17
[   44.500473] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   44.509819] Call Trace:
[   44.512389]  dump_stack+0x185/0x1d0
[   44.515997]  kmsan_report+0x188/0x2a0
[   44.519784]  kmsan_internal_check_memory+0x17e/0x1f0
[   44.524868]  kmsan_copy_to_user+0x7a/0x160
[   44.529088]  copy_from_read_buf+0x311/0x890
[   44.533387]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[   44.538746]  n_tty_read+0x178f/0x2f70
[   44.542525]  ? wait_woken+0x2e0/0x2e0
[   44.546306]  ? rcu_all_qs+0x32/0x1f0
[   44.550006]  ? _cond_resched+0x3c/0xd0
[   44.553877]  ? ldsem_down_read+0x95/0xad0
[   44.558011]  ? tty_ldisc_ref_wait+0x97/0xf0
[   44.562322]  ? n_tty_flush_buffer+0x430/0x430
[   44.566799]  tty_read+0x26e/0x6c0
[   44.570239]  ? release_one_tty+0x5f0/0x5f0
[   44.574453]  __vfs_read+0x1b2/0x9d0
[   44.578073]  vfs_read+0x36c/0x6b0
[   44.581521]  __x64_sys_read+0x1bf/0x3e0
[   44.585478]  ? ksys_read+0x360/0x360
[   44.589173]  do_syscall_64+0x15b/0x230
[   44.593046]  entry_SYSCALL_64_after_hwframe+0x63/0xe7
[   44.598214] RIP: 0033:0x440239
[   44.601380] RSP: 002b:00007ffdd9140bc8 EFLAGS: 00000217 ORIG_RAX: 0000000000000000
[   44.609068] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000440239
[   44.616322] RDX: 00000000ffffff5c RSI: 0000000020000080 RDI: 0000000000000004
[   44.623573] RBP: 6d74702f7665642f R08: 000000000000000a R09: 00007ffdd9140c40
[   44.630827] R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000401b00
[   44.638082] R13: 0000000000401b90 R14: 0000000000000000 R15: 0000000000000000
[   44.645346] 
[   44.646967] Uninit was created at:
[   44.650508]  kmsan_alloc_meta_for_pages+0x15c/0x710
[   44.655506]  kmsan_alloc_page+0x87/0xe0
[   44.659460]  __alloc_pages_nodemask+0xf7b/0x5cc0
[   44.664201]  alloc_pages_current+0x6b1/0x970
[   44.668586]  __vmalloc_node_range+0x8bf/0x1170
[   44.673145]  vmalloc+0xd8/0xf0
[   44.676319]  n_tty_open+0x4a/0x490
[   44.679841]  tty_ldisc_setup+0x375/0x670
[   44.683889]  tty_init_dev+0xb82/0x1020
[   44.687763]  ptmx_open+0x2bb/0x7c0
[   44.691282]  chrdev_open+0xc25/0xd90
[   44.694972]  do_dentry_open+0xccc/0x1440
[   44.699023]  vfs_open+0x1b6/0x2f0
[   44.702462]  path_openat+0x4771/0x6640
[   44.706334]  do_filp_open+0x261/0x640
[   44.710111]  do_sys_open+0x624/0x960
[   44.713801]  __x64_sys_openat+0x129/0x170
[   44.717935]  do_syscall_64+0x15b/0x230
[   44.721815]  entry_SYSCALL_64_after_hwframe+0x63/0xe7
[   44.727070] 
[   44.728696] Byte 4094 of 4095 is uninitialized
[   44.733270] Memory access starts at ffffc900018af05e
[   44.738377] ==================================================================
[   44.745735] Disabling lock debugging due to kernel taint
[   44.751184] Kernel panic - not syncing: panic_on_warn set ...
[   44.751184] 
[   44.758535] CPU: 0 PID: 4519 Comm: syz-executor294 Tainted: G    B             4.17.0+ #17
[   44.766922] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   44.776260] Call Trace:
[   44.778830]  dump_stack+0x185/0x1d0
[   44.782437]  panic+0x3d0/0x990
[   44.785611]  kmsan_report+0x29e/0x2a0
[   44.789396]  kmsan_internal_check_memory+0x17e/0x1f0
[   44.794500]  kmsan_copy_to_user+0x7a/0x160
[   44.798722]  copy_from_read_buf+0x311/0x890
[   44.803029]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[   44.808389]  n_tty_read+0x178f/0x2f70
[   44.812174]  ? wait_woken+0x2e0/0x2e0
[   44.815960]  ? rcu_all_qs+0x32/0x1f0
[   44.819652]  ? _cond_resched+0x3c/0xd0
[   44.823521]  ? ldsem_down_read+0x95/0xad0
[   44.827675]  ? tty_ldisc_ref_wait+0x97/0xf0
[   44.832006]  ? n_tty_flush_buffer+0x430/0x430
[   44.836486]  tty_read+0x26e/0x6c0
[   44.839934]  ? release_one_tty+0x5f0/0x5f0
[   44.844153]  __vfs_read+0x1b2/0x9d0
[   44.847764]  vfs_read+0x36c/0x6b0
[   44.851195]  __x64_sys_read+0x1bf/0x3e0
[   44.855160]  ? ksys_read+0x360/0x360
[   44.858852]  do_syscall_64+0x15b/0x230
[   44.862722]  entry_SYSCALL_64_after_hwframe+0x63/0xe7
[   44.867896] RIP: 0033:0x440239
[   44.871068] RSP: 002b:00007ffdd9140bc8 EFLAGS: 00000217 ORIG_RAX: 0000000000000000
[   44.878759] RAX: ffffffffffffffda RBX: ffffffffffffffff RCX: 0000000000440239
[   44.886011] RDX: 00000000ffffff5c RSI: 0000000020000080 RDI: 0000000000000004
[   44.893268] RBP: 6d74702f7665642f R08: 000000000000000a R09: 00007ffdd9140c40
[   44.900516] R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000401b00
[   44.907776] R13: 0000000000401b90 R14: 0000000000000000 R15: 0000000000000000
[   44.915568] Dumping ftrace buffer:
[   44.919097]    (ftrace buffer empty)
[   44.922786] Kernel Offset: disabled
[   44.926393] Rebooting in 86400 seconds..