[....] 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[ 16.521719] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.002294] random: sshd: uninitialized urandom read (32 bytes read) [ 19.330305] random: sshd: uninitialized urandom read (32 bytes read) [ 19.849826] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.52' (ECDSA) to the list of known hosts. [ 25.412809] urandom_read: 1 callbacks suppressed [ 25.412812] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 25.514909] BUG: unable to handle kernel paging request at ffffeafff91b8020 [ 25.522245] IP: [] page_remove_rmap+0x37/0x6d0 [ 25.528484] PGD 0 [ 25.530427] [ 25.532048] Oops: 0000 [#1] PREEMPT SMP KASAN [ 25.536516] Dumping ftrace buffer: [ 25.540027] (ftrace buffer empty) [ 25.543734] Modules linked in: [ 25.547018] CPU: 1 PID: 3796 Comm: syz-executor311 Not tainted 4.9.120-gf85543b #24 [ 25.554780] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.564122] task: ffff8801b775e000 task.stack: ffff8801b62c8000 [ 25.570148] RIP: 0010:[] [] page_remove_rmap+0x37/0x6d0 [ 25.578817] RSP: 0018:ffff8801b62cf948 EFLAGS: 00010246 [ 25.584238] RAX: dffffc0000000000 RBX: ffffeafff91b8000 RCX: 0000000000000000 [ 25.591478] RDX: 1ffffd5fff237004 RSI: ffffffff814f5128 RDI: ffffeafff91b8000 [ 25.598767] RBP: ffff8801b62cf970 R08: 0000000000033bc0 R09: 0000000000000001 [ 25.606018] R10: ffff8801b775e000 R11: 0000000000000001 R12: ffff8801b62cfc08 [ 25.613265] R13: ffffeafff91b8020 R14: ffffeafff91b8000 R15: 0000000000000001 [ 25.620954] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 25.629156] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 25.635010] CR2: ffffeafff91b8020 CR3: 00000001bcc99000 CR4: 00000000001606f0 [ 25.642266] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 25.649558] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 25.656808] Stack: [ 25.658930] ffffeafff91b8020 ffff8801b62cfc08 ffff8801bab63800 ffffeafff91b8000 [ 25.667019] ffff8801b6419d68 ffff8801b62cf9c8 ffffffff8154bfcf ffff8801b62cfc18 [ 25.675003] ffff8801b62cfc10 ffff8801b62cfc88 00003ffe46e001e0 00000001bab63000 [ 25.682997] Call Trace: [ 25.685562] [] zap_huge_pmd+0x16f/0x860 [ 25.691177] [] unmap_page_range+0x12ad/0x1730 [ 25.697304] [] ? vm_normal_page_pmd+0x2f0/0x2f0 [ 25.703599] [] unmap_single_vma+0x101/0x260 [ 25.709541] [] unmap_vmas+0x102/0x1d0 [ 25.714975] [] exit_mmap+0x214/0x3f0 [ 25.720310] [] ? SyS_munmap+0xa0/0xa0 [ 25.725739] [] ? up_write+0x1a/0x60 [ 25.730992] [] mmput+0xf3/0x2d0 [ 25.735960] [] do_exit+0x906/0x27b0 [ 25.741219] [] ? release_task.part.19+0x1210/0x1210 [ 25.747860] [] ? up_write+0x1a/0x60 [ 25.753627] [] ? do_mprotect_pkey+0x71d/0x890 [ 25.759743] [] ? mprotect_fixup+0x930/0x930 [ 25.765700] [] do_group_exit+0x111/0x340 [ 25.771396] [] ? do_group_exit+0x340/0x340 [ 25.777253] [] SyS_exit_group+0x1d/0x20 [ 25.782887] [] do_syscall_64+0x1a6/0x490 [ 25.788578] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.795471] 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 [ 25.822305] RIP [] page_remove_rmap+0x37/0x6d0 [ 25.828628] RSP [ 25.832227] CR2: ffffeafff91b8020 [ 25.835671] ---[ end trace e77ef8d8ac0b4673 ]--- [ 25.840395] Kernel panic - not syncing: Fatal exception [ 25.846140] Dumping ftrace buffer: [ 25.849657] (ftrace buffer empty) [ 25.853343] Kernel Offset: disabled [ 25.856945] Rebooting in 86400 seconds..