[....] 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[ 13.035318] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 16.014528] random: sshd: uninitialized urandom read (32 bytes read) [ 16.234336] random: sshd: uninitialized urandom read (32 bytes read) [ 16.730564] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.6' (ECDSA) to the list of known hosts. [ 22.467814] urandom_read: 1 callbacks suppressed [ 22.467818] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 22.564683] BUG: unable to handle kernel paging request at ffffeafff8d88020 [ 22.572200] IP: [] page_remove_rmap+0x37/0x6d0 [ 22.578512] PGD 0 [ 22.580470] [ 22.582308] Oops: 0000 [#1] PREEMPT SMP KASAN [ 22.586783] Dumping ftrace buffer: [ 22.590372] (ftrace buffer empty) [ 22.594069] Modules linked in: [ 22.597589] CPU: 1 PID: 3666 Comm: syz-executor940 Not tainted 4.9.122-g54068d6 #78 [ 22.605414] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 22.614762] task: ffff8801c3853000 task.stack: ffff8801c2840000 [ 22.620796] RIP: 0010:[] [] page_remove_rmap+0x37/0x6d0 [ 22.629478] RSP: 0018:ffff8801c2847948 EFLAGS: 00010246 [ 22.634905] RAX: dffffc0000000000 RBX: ffffeafff8d88000 RCX: 0000000000000000 [ 22.642275] RDX: 1ffffd5fff1b1004 RSI: ffffffff814f5918 RDI: ffffeafff8d88000 [ 22.649559] RBP: ffff8801c2847970 R08: 0000000000033bc0 R09: 0000000000000001 [ 22.656942] R10: ffff8801c3853000 R11: 0000000000000001 R12: ffff8801c2847c08 [ 22.664402] R13: ffffeafff8d88020 R14: ffffeafff8d88000 R15: 0000000000000001 [ 22.671765] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 22.679970] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 22.685832] CR2: ffffeafff8d88020 CR3: 00000001c3153000 CR4: 00000000001606f0 [ 22.693082] Stack: [ 22.695209] ffffeafff8d88020 ffff8801c2847c08 ffff8801c2d1c800 ffffeafff8d88000 [ 22.703196] ffff8801c3605bb0 ffff8801c28479c8 ffffffff8154cb8f ffff8801c2847c18 [ 22.711194] ffff8801c2847c10 ffff8801c2847c88 00003ffe362001e0 00000001c2d1c000 [ 22.719190] Call Trace: [ 22.721756] [] zap_huge_pmd+0x16f/0x860 [ 22.727367] [] unmap_page_range+0x12ad/0x1730 [ 22.733523] [] ? vm_normal_page_pmd+0x310/0x310 [ 22.739831] [] unmap_single_vma+0x101/0x260 [ 22.745787] [] unmap_vmas+0x102/0x1d0 [ 22.751217] [] exit_mmap+0x214/0x3f0 [ 22.756565] [] ? SyS_munmap+0xa0/0xa0 [ 22.761996] [] ? up_write+0x1a/0x60 [ 22.767254] [] mmput+0xf3/0x2d0 [ 22.772165] [] do_exit+0x906/0x27b0 [ 22.777427] [] ? release_task.part.19+0x1210/0x1210 [ 22.784295] [] ? up_write+0x1a/0x60 [ 22.789557] [] ? do_mprotect_pkey+0x71d/0x890 [ 22.795757] [] ? mprotect_fixup+0x930/0x930 [ 22.801718] [] do_group_exit+0x111/0x340 [ 22.807407] [] ? do_group_exit+0x340/0x340 [ 22.813269] [] SyS_exit_group+0x1d/0x20 [ 22.818869] [] do_syscall_64+0x1a6/0x490 [ 22.824574] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 22.831485] Code: 55 41 54 53 48 89 fb e8 58 b4 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 23 b4 e6 [ 22.859170] RIP [] page_remove_rmap+0x37/0x6d0 [ 22.865560] RSP [ 22.869162] CR2: ffffeafff8d88020 [ 22.872605] ---[ end trace 0ec51252469048ff ]--- [ 22.877378] Kernel panic - not syncing: Fatal exception [ 22.883061] Dumping ftrace buffer: [ 22.886587] (ftrace buffer empty) [ 22.890280] Kernel Offset: disabled [ 22.893885] Rebooting in 86400 seconds..