[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 13.568395] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 30.497827] random: sshd: uninitialized urandom read (32 bytes read) [ 30.643682] random: sshd: uninitialized urandom read (32 bytes read) [ 31.160053] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.15.194' (ECDSA) to the list of known hosts. [ 36.832281] urandom_read: 1 callbacks suppressed [ 36.832284] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 36.920073] BUG: unable to handle kernel paging request at ffffeafff8e58020 [ 36.927570] IP: [] page_remove_rmap+0x37/0x6d0 [ 36.933833] PGD 0 [ 36.935784] [ 36.937432] Oops: 0000 [#1] PREEMPT SMP KASAN [ 36.941981] Dumping ftrace buffer: [ 36.945501] (ftrace buffer empty) [ 36.949185] Modules linked in: [ 36.952501] CPU: 0 PID: 3809 Comm: syz-executor400 Not tainted 4.9.121-g681e57b #77 [ 36.960264] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 36.969591] task: ffff8801b81c9800 task.stack: ffff8801b73c8000 [ 36.975616] RIP: 0010:[] [] page_remove_rmap+0x37/0x6d0 [ 36.984315] RSP: 0018:ffff8801b73cf948 EFLAGS: 00010246 [ 36.989738] RAX: dffffc0000000000 RBX: ffffeafff8e58000 RCX: 0000000000000000 [ 36.997046] RDX: 1ffffd5fff1cb004 RSI: ffffffff814f5278 RDI: ffffeafff8e58000 [ 37.004313] RBP: ffff8801b73cf970 R08: 00000000000341a0 R09: 0000000000000001 [ 37.011757] R10: ffff8801b81c9800 R11: 0000000000000001 R12: ffff8801b73cfc08 [ 37.019058] R13: ffffeafff8e58020 R14: ffffeafff8e58000 R15: 0000000000000001 [ 37.026321] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 37.034519] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 37.040372] CR2: ffffeafff8e58020 CR3: 00000001cb746000 CR4: 00000000001606f0 [ 37.047661] Stack: [ 37.049786] ffffeafff8e58020 ffff8801b73cfc08 ffff8801c34f9800 ffffeafff8e58000 [ 37.057777] ffff8801c122eb00 ffff8801b73cf9c8 ffffffff8154c20f ffff8801b73cfc18 [ 37.065783] ffff8801b73cfc10 ffff8801b73cfc88 00003ffe396001e0 00000001c34f9000 [ 37.074000] Call Trace: [ 37.076566] [] zap_huge_pmd+0x16f/0x860 [ 37.082266] [] unmap_page_range+0x12ad/0x1730 [ 37.088488] [] ? vm_normal_page_pmd+0x2f0/0x2f0 [ 37.094804] [] unmap_single_vma+0x101/0x260 [ 37.100749] [] unmap_vmas+0x102/0x1d0 [ 37.106170] [] exit_mmap+0x214/0x3f0 [ 37.111504] [] ? SyS_munmap+0xa0/0xa0 [ 37.116926] [] ? up_write+0x1a/0x60 [ 37.122178] [] mmput+0xf3/0x2d0 [ 37.127087] [] do_exit+0x906/0x27b0 [ 37.132387] [] ? release_task.part.19+0x1210/0x1210 [ 37.139035] [] ? up_write+0x1a/0x60 [ 37.144301] [] ? do_mprotect_pkey+0x71d/0x890 [ 37.150437] [] ? mprotect_fixup+0x930/0x930 [ 37.156419] [] ? key_get_type_from_user.constprop.9+0xe0/0xe0 [ 37.163929] [] do_group_exit+0x111/0x340 [ 37.169631] [] ? do_group_exit+0x340/0x340 [ 37.175502] [] SyS_exit_group+0x1d/0x20 [ 37.181100] [] do_syscall_64+0x1a6/0x490 [ 37.186782] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 37.193817] Code: 55 41 54 53 48 89 fb e8 c8 b6 e6 ff 4c 8d 6b 20 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 b8 05 00 00 <4c> 8b 73 20 49 89 dc 41 f6 c6 01 0f 85 4b 03 00 00 e8 93 b6 e6 [ 37.220947] RIP [] page_remove_rmap+0x37/0x6d0 [ 37.227281] RSP [ 37.230876] CR2: ffffeafff8e58020 [ 37.234357] ---[ end trace 52af0a215f37429d ]--- [ 37.239088] Kernel panic - not syncing: Fatal exception [ 37.244680] Dumping ftrace buffer: [ 37.248196] (ftrace buffer empty) [ 37.251877] Kernel Offset: disabled [ 37.255473] Rebooting in 86400 seconds..