[....] 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[ 12.183836] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 29.929059] random: sshd: uninitialized urandom read (32 bytes read) [ 30.406137] random: sshd: uninitialized urandom read (32 bytes read) [ 30.788935] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.51' (ECDSA) to the list of known hosts. [ 36.286834] urandom_read: 1 callbacks suppressed [ 36.286838] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 36.370686] BUG: unable to handle kernel paging request at ffffeafff8f38020 [ 36.378074] IP: [] page_remove_rmap+0x37/0x6d0 [ 36.384318] PGD 0 [ 36.386268] [ 36.387887] Oops: 0000 [#1] PREEMPT SMP KASAN [ 36.392351] Dumping ftrace buffer: [ 36.395862] (ftrace buffer empty) [ 36.399553] Modules linked in: [ 36.402837] CPU: 1 PID: 3722 Comm: syz-executor103 Not tainted 4.9.120-gf85543b #76 [ 36.410599] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 36.419927] task: ffff8801c0478000 task.stack: ffff8801bfa28000 [ 36.425953] RIP: 0010:[] [] page_remove_rmap+0x37/0x6d0 [ 36.434622] RSP: 0018:ffff8801bfa2f948 EFLAGS: 00010246 [ 36.440051] RAX: dffffc0000000000 RBX: ffffeafff8f38000 RCX: 0000000000000000 [ 36.447291] RDX: 1ffffd5fff1e7004 RSI: ffffffff814f5128 RDI: ffffeafff8f38000 [ 36.454539] RBP: ffff8801bfa2f970 R08: 0000000000033860 R09: 0000000000000001 [ 36.461793] R10: ffff8801c0478000 R11: 0000000000000001 R12: ffff8801bfa2fc08 [ 36.469039] R13: ffffeafff8f38020 R14: ffffeafff8f38000 R15: 0000000000000001 [ 36.476292] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 36.484490] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 36.490343] CR2: ffffeafff8f38020 CR3: 00000001cb344000 CR4: 00000000001606f0 [ 36.497583] Stack: [ 36.499705] ffffeafff8f38020 ffff8801bfa2fc08 ffff8801cb235800 ffffeafff8f38000 [ 36.507713] ffff8801c04fa420 ffff8801bfa2f9c8 ffffffff8154bfcf ffff8801bfa2fc18 [ 36.515869] ffff8801bfa2fc10 ffff8801bfa2fc88 00003ffe3ce001e0 00000001cb235000 [ 36.523871] Call Trace: [ 36.526452] [] zap_huge_pmd+0x16f/0x860 [ 36.532053] [] unmap_page_range+0x12ad/0x1730 [ 36.538171] [] ? vm_normal_page_pmd+0x2f0/0x2f0 [ 36.544565] [] unmap_single_vma+0x101/0x260 [ 36.550522] [] unmap_vmas+0x102/0x1d0 [ 36.555946] [] exit_mmap+0x214/0x3f0 [ 36.561282] [] ? SyS_munmap+0xa0/0xa0 [ 36.566709] [] ? up_write+0x1a/0x60 [ 36.571960] [] mmput+0xf3/0x2d0 [ 36.576862] [] do_exit+0x906/0x27b0 [ 36.582111] [] ? release_task.part.19+0x1210/0x1210 [ 36.588762] [] ? up_write+0x1a/0x60 [ 36.594011] [] ? do_mprotect_pkey+0x71d/0x890 [ 36.600129] [] ? mprotect_fixup+0x930/0x930 [ 36.606074] [] do_group_exit+0x111/0x340 [ 36.611761] [] ? do_group_exit+0x340/0x340 [ 36.617621] [] SyS_exit_group+0x1d/0x20 [ 36.623326] [] do_syscall_64+0x1a6/0x490 [ 36.629071] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 36.636001] 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 [ 36.662870] RIP [] page_remove_rmap+0x37/0x6d0 [ 36.669199] RSP [ 36.672805] CR2: ffffeafff8f38020 [ 36.676233] ---[ end trace 94a146a91ec87393 ]--- [ 36.680958] Kernel panic - not syncing: Fatal exception [ 36.686582] Dumping ftrace buffer: [ 36.690097] (ftrace buffer empty) [ 36.693782] Kernel Offset: disabled [ 36.697378] Rebooting in 86400 seconds..