[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[   32.387077] random: sshd: uninitialized urandom read (32 bytes read)
[?25l[?1c7[ ok 8[?25h[?0c.

Debian GNU/Linux 7 syzkaller ttyS0

syzkaller login: [   36.361111] random: sshd: uninitialized urandom read (32 bytes read)
[   36.968861] random: sshd: uninitialized urandom read (32 bytes read)
[   38.193823] random: sshd: uninitialized urandom read (32 bytes read)
[   38.415804] random: sshd: uninitialized urandom read (32 bytes read)
Warning: Permanently added '10.128.10.7' (ECDSA) to the list of known hosts.
[   43.985371] random: sshd: uninitialized urandom read (32 bytes read)
executing program
[   44.108605] ==================================================================
[   44.115998] BUG: KMSAN: uninit-value in move_addr_to_user+0x32e/0x530
[   44.122557] CPU: 0 PID: 4549 Comm: syz-executor287 Not tainted 4.17.0-rc3+ #88
[   44.129895] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   44.139233] Call Trace:
[   44.141822]  dump_stack+0x185/0x1d0
[   44.145446]  ? kmsan_internal_check_memory+0x116/0x1e0
[   44.150707]  kmsan_report+0x142/0x240
[   44.154493]  kmsan_internal_check_memory+0x135/0x1e0
[   44.159581]  kmsan_copy_to_user+0x69/0x160
[   44.163802]  move_addr_to_user+0x32e/0x530
[   44.168023]  ___sys_recvmsg+0x4e2/0x810
[   44.171987]  ? __msan_metadata_ptr_for_load_1+0x10/0x20
[   44.177328]  ? __fget_light+0x6b9/0x710
[   44.181282]  __x64_sys_recvmsg+0x325/0x460
[   44.185507]  do_syscall_64+0x154/0x220
[   44.189377]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   44.194543] RIP: 0033:0x4455e9
[   44.197709] RSP: 002b:00007fe3bd36ddb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
[   44.205394] RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 00000000004455e9
[   44.212640] RDX: 0000000000002002 RSI: 0000000020000400 RDI: 0000000000000003
[   44.219890] RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000
[   44.227136] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[   44.234382] R13: 00007fff98ce4b6f R14: 00007fe3bd36e9c0 R15: 0000000000000003
[   44.241631] 
[   44.243237] Local variable description: ----addr@___sys_recvmsg
[   44.249267] Variable was created at:
[   44.252958]  ___sys_recvmsg+0xd5/0x810
[   44.256819]  __x64_sys_recvmsg+0x325/0x460
[   44.261026] 
[   44.262635] Byte 19 of 32 is uninitialized
[   44.266839] ==================================================================
[   44.274171] Disabling lock debugging due to kernel taint
[   44.279595] Kernel panic - not syncing: panic_on_warn set ...
[   44.279595] 
[   44.286936] CPU: 0 PID: 4549 Comm: syz-executor287 Tainted: G    B             4.17.0-rc3+ #88
[   44.295658] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   44.304984] Call Trace:
[   44.307553]  dump_stack+0x185/0x1d0
[   44.311167]  panic+0x39d/0x940
[   44.314357]  ? kmsan_internal_check_memory+0x116/0x1e0
[   44.319610]  kmsan_report+0x238/0x240
[   44.323388]  kmsan_internal_check_memory+0x135/0x1e0
[   44.328470]  kmsan_copy_to_user+0x69/0x160
[   44.332687]  move_addr_to_user+0x32e/0x530
[   44.336989]  ___sys_recvmsg+0x4e2/0x810
[   44.340948]  ? __msan_metadata_ptr_for_load_1+0x10/0x20
[   44.346287]  ? __fget_light+0x6b9/0x710
[   44.350240]  __x64_sys_recvmsg+0x325/0x460
[   44.354453]  do_syscall_64+0x154/0x220
[   44.358319]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   44.363481] RIP: 0033:0x4455e9
[   44.366647] RSP: 002b:00007fe3bd36ddb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
[   44.374341] RAX: ffffffffffffffda RBX: 00000000006dac24 RCX: 00000000004455e9
[   44.381585] RDX: 0000000000002002 RSI: 0000000020000400 RDI: 0000000000000003
[   44.388838] RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000
[   44.396089] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[   44.403335] R13: 00007fff98ce4b6f R14: 00007fe3bd36e9c0 R15: 0000000000000003
[   44.411043] Dumping ftrace buffer:
[   44.414573]    (ftrace buffer empty)
[   44.418255] Kernel Offset: disabled
[   44.421855] Rebooting in 86400 seconds..