[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.942373] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 24.882518] random: sshd: uninitialized urandom read (32 bytes read) [ 25.440258] random: sshd: uninitialized urandom read (32 bytes read) [ 26.193695] random: sshd: uninitialized urandom read (32 bytes read) [ 32.458424] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.50' (ECDSA) to the list of known hosts. [ 37.942601] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 38.055134] ------------[ cut here ]------------ [ 38.060223] Bad or missing usercopy whitelist? Kernel memory exposure attempt detected from SLAB object 'kvm_vcpu' (offset 23192, size 8)! [ 38.073179] WARNING: CPU: 0 PID: 4534 at mm/usercopy.c:81 usercopy_warn+0xf5/0x120 [ 38.080874] Kernel panic - not syncing: panic_on_warn set ... [ 38.080874] [ 38.088221] CPU: 0 PID: 4534 Comm: syz-executor298 Not tainted 4.17.0-rc5+ #57 [ 38.095565] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.104898] Call Trace: [ 38.107481] dump_stack+0x1b9/0x294 [ 38.111093] ? dump_stack_print_info.cold.2+0x52/0x52 [ 38.116271] ? usercopy_warn+0xf0/0x120 [ 38.120230] panic+0x22f/0x4de [ 38.123407] ? add_taint.cold.5+0x16/0x16 [ 38.127540] ? __warn.cold.8+0x148/0x1b3 [ 38.131592] ? __warn.cold.8+0x117/0x1b3 [ 38.135728] ? usercopy_warn+0xf5/0x120 [ 38.139685] __warn.cold.8+0x163/0x1b3 [ 38.143562] ? usercopy_warn+0xf5/0x120 [ 38.147527] report_bug+0x252/0x2d0 [ 38.151142] do_error_trap+0x1de/0x490 [ 38.155013] ? math_error+0x420/0x420 [ 38.158800] ? vprintk_default+0x28/0x30 [ 38.162845] ? vprintk_func+0x81/0xe7 [ 38.166629] ? printk+0x9e/0xba [ 38.169895] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 38.174732] do_invalid_op+0x1b/0x20 [ 38.178432] invalid_op+0x14/0x20 [ 38.181872] RIP: 0010:usercopy_warn+0xf5/0x120 [ 38.186450] RSP: 0018:ffff8801afabf0b0 EFLAGS: 00010286 [ 38.191802] RAX: 000000000000007e RBX: ffffffff889d52f0 RCX: ffffffff8160aa5d [ 38.199052] RDX: 0000000000000000 RSI: ffffffff8160f711 RDI: ffff8801afabec10 [ 38.206307] RBP: ffff8801afabf110 R08: ffff8801ae7f42c0 R09: 0000000000000006 [ 38.213557] R10: ffff8801ae7f42c0 R11: 0000000000000000 R12: ffffffff87d2fa60 [ 38.220810] R13: ffffffff87c19ec0 R14: 0000000000000000 R15: 0000000000000008 [ 38.228077] ? console_unlock+0x8ad/0x1100 [ 38.232297] ? vprintk_func+0x81/0xe7 [ 38.236086] __check_heap_object+0x89/0xb5 [ 38.240305] __check_object_size+0x4c7/0x5d9 [ 38.244702] ? usercopy_warn+0x120/0x120 [ 38.248762] ? __might_sleep+0x95/0x190 [ 38.252727] __kvm_write_guest_page+0x90/0x140 [ 38.257292] kvm_vcpu_write_guest+0x65/0xe0 [ 38.261600] kvm_write_guest_virt_system+0x8a/0x190 [ 38.266600] ? vmx_vcpu_run+0xb16/0x25f0 [ 38.270644] handle_vmptrst+0x1d2/0x260 [ 38.274600] ? handle_vmclear+0x550/0x550 [ 38.278729] ? __lock_is_held+0xb5/0x140 [ 38.282859] ? __vmx_complete_interrupts+0x103/0x3e0 [ 38.287947] ? handle_vmclear+0x550/0x550 [ 38.292086] vmx_handle_exit+0x2c0/0x17b0 [ 38.296225] ? lock_acquire+0x1dc/0x520 [ 38.300184] ? vcpu_enter_guest+0x11f8/0x6060 [ 38.304749] ? vmx_save_host_state+0xa60/0xa60 [ 38.309312] ? handle_vmfunc+0x9c0/0x9c0 [ 38.313369] ? vcpu_enter_guest+0x119a/0x6060 [ 38.317851] vcpu_enter_guest+0x13af/0x6060 [ 38.322267] ? kasan_check_read+0x11/0x20 [ 38.326403] ? kvm_set_msr_common+0x2680/0x2680 [ 38.331062] ? vmx_vcpu_load+0xadd/0xfe0 [ 38.335104] ? find_held_lock+0x36/0x1c0 [ 38.339146] ? vmx_vcpu_reset+0x1030/0x1030 [ 38.343450] ? graph_lock+0x170/0x170 [ 38.347234] ? graph_lock+0x170/0x170 [ 38.351016] ? lock_downgrade+0x8e0/0x8e0 [ 38.355148] ? __kasan_slab_free+0x11a/0x170 [ 38.359542] ? kasan_slab_free+0xe/0x10 [ 38.363512] ? kfree+0xd9/0x260 [ 38.366802] ? kvm_vcpu_ioctl+0xb26/0x12e0 [ 38.371020] ? do_vfs_ioctl+0x1cf/0x16a0 [ 38.375076] ? __lock_is_held+0xb5/0x140 [ 38.379133] ? lock_acquire+0x1dc/0x520 [ 38.383091] ? kvm_check_async_pf_completion+0x39b/0x5a0 [ 38.388525] ? kvm_clear_async_pf_completion_queue+0x780/0x780 [ 38.394481] ? kvm_arch_dev_ioctl+0x5f0/0x5f0 [ 38.398958] ? preempt_notifier_dec+0x20/0x20 [ 38.403451] kvm_arch_vcpu_ioctl_run+0x33e/0x1690 [ 38.408276] ? kvm_arch_vcpu_ioctl_run+0x33e/0x1690 [ 38.413280] kvm_vcpu_ioctl+0x79d/0x12e0 [ 38.417326] ? kvm_uevent_notify_change.part.29+0x440/0x440 [ 38.423024] ? kasan_check_read+0x11/0x20 [ 38.427159] ? do_raw_spin_unlock+0x9e/0x2e0 [ 38.431553] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 38.436126] ? add_mm_counter_fast+0xd0/0xd0 [ 38.440529] ? lock_downgrade+0x8e0/0x8e0 [ 38.444674] ? _raw_spin_unlock+0x22/0x30 [ 38.448806] ? __handle_mm_fault+0x93a/0x4310 [ 38.453386] ? vm_insert_mixed_mkwrite+0x40/0x40 [ 38.458123] ? graph_lock+0x170/0x170 [ 38.461908] ? rcu_is_watching+0x85/0x140 [ 38.466042] ? graph_lock+0x170/0x170 [ 38.469835] ? find_held_lock+0x36/0x1c0 [ 38.473883] ? find_held_lock+0x36/0x1c0 [ 38.477930] ? lock_downgrade+0x8e0/0x8e0 [ 38.482067] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 38.487248] ? kvm_uevent_notify_change.part.29+0x440/0x440 [ 38.492950] do_vfs_ioctl+0x1cf/0x16a0 [ 38.496825] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 38.502390] ? ioctl_preallocate+0x2e0/0x2e0 [ 38.506794] ? fget_raw+0x20/0x20 [ 38.510237] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 38.515757] ? __do_page_fault+0x441/0xe40 [ 38.519989] ? mm_fault_error+0x380/0x380 [ 38.524303] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 38.529958] ? security_file_ioctl+0x94/0xc0 [ 38.534360] ksys_ioctl+0xa9/0xd0 [ 38.537798] __x64_sys_ioctl+0x73/0xb0 [ 38.541671] do_syscall_64+0x1b1/0x800 [ 38.545540] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 38.550368] ? syscall_return_slowpath+0x5c0/0x5c0 [ 38.555282] ? syscall_return_slowpath+0x30f/0x5c0 [ 38.560208] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 38.565555] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 38.570381] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 38.575556] RIP: 0033:0x443039 [ 38.578727] RSP: 002b:00007ffe00412648 EFLAGS: 00000286 ORIG_RAX: 0000000000000010 [ 38.586433] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000443039 [ 38.593684] RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 [ 38.600936] RBP: 00000000006cd018 R08: 0000000020000580 R09: 0000000020000580 [ 38.608186] R10: 0000000000000000 R11: 0000000000000286 R12: 0000000000404080 [ 38.615436] R13: 0000000000404110 R14: 0000000000000000 R15: 0000000000000000 [ 38.623482] Dumping ftrace buffer: [ 38.627173] (ftrace buffer empty) [ 38.630865] Kernel Offset: disabled [ 38.634475] Rebooting in 86400 seconds..