[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 13.302772] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.294938] random: sshd: uninitialized urandom read (32 bytes read) [ 19.717886] random: sshd: uninitialized urandom read (32 bytes read) [ 20.238830] random: sshd: uninitialized urandom read (32 bytes read) [ 20.373846] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.23' (ECDSA) to the list of known hosts. [ 25.811145] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 25.898747] BUG: unable to handle kernel paging request at ffffeafff91a8020 [ 25.906136] IP: [] page_remove_rmap+0x37/0x6d0 [ 25.912492] PGD 0 [ 25.914544] [ 25.916171] Oops: 0000 [#1] PREEMPT SMP KASAN [ 25.920647] Dumping ftrace buffer: [ 25.924163] (ftrace buffer empty) [ 25.927854] Modules linked in: [ 25.931148] CPU: 0 PID: 3804 Comm: syz-executor969 Not tainted 4.9.120-gf85543b #76 [ 25.938922] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.948267] task: ffff8801b74f3000 task.stack: ffff8801b5df0000 [ 25.954307] RIP: 0010:[] [] page_remove_rmap+0x37/0x6d0 [ 25.962995] RSP: 0018:ffff8801b5df7948 EFLAGS: 00010246 [ 25.968423] RAX: dffffc0000000000 RBX: ffffeafff91a8000 RCX: 0000000000000000 [ 25.975675] RDX: 1ffffd5fff235004 RSI: ffffffff814f5128 RDI: ffffeafff91a8000 [ 25.982933] RBP: ffff8801b5df7970 R08: 0000000000033cc0 R09: 0000000000000001 [ 25.990259] R10: ffff8801b74f3000 R11: 0000000000000001 R12: ffff8801b5df7c08 [ 25.997524] R13: ffffeafff91a8020 R14: ffffeafff91a8000 R15: 0000000000000001 [ 26.004777] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 26.013051] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 26.018919] CR2: ffffeafff91a8020 CR3: 00000001c8581000 CR4: 00000000001606f0 [ 26.026175] Stack: [ 26.028313] ffffeafff91a8020 ffff8801b5df7c08 ffff8801c87b3800 ffffeafff91a8000 [ 26.036303] ffff8801c857e1b8 ffff8801b5df79c8 ffffffff8154bfcf ffff8801b5df7c18 [ 26.044301] ffff8801b5df7c10 ffff8801b5df7c88 00003ffe46a001e0 00000001c87b3000 [ 26.052362] Call Trace: [ 26.054933] [] zap_huge_pmd+0x16f/0x860 [ 26.060538] [] unmap_page_range+0x12ad/0x1730 [ 26.066668] [] ? vm_normal_page_pmd+0x2f0/0x2f0 [ 26.073051] [] unmap_single_vma+0x101/0x260 [ 26.079006] [] unmap_vmas+0x102/0x1d0 [ 26.084436] [] exit_mmap+0x214/0x3f0 [ 26.089780] [] ? SyS_munmap+0xa0/0xa0 [ 26.095217] [] ? up_write+0x1a/0x60 [ 26.100477] [] mmput+0xf3/0x2d0 [ 26.105410] [] do_exit+0x906/0x27b0 [ 26.110666] [] ? release_task.part.19+0x1210/0x1210 [ 26.117310] [] ? up_write+0x1a/0x60 [ 26.122573] [] ? do_mprotect_pkey+0x71d/0x890 [ 26.128697] [] ? mprotect_fixup+0x930/0x930 [ 26.134651] [] do_group_exit+0x111/0x340 [ 26.140339] [] ? do_group_exit+0x340/0x340 [ 26.146352] [] SyS_exit_group+0x1d/0x20 [ 26.151958] [] do_syscall_64+0x1a6/0x490 [ 26.157674] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 26.164579] 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 [ 26.191685] RIP [] page_remove_rmap+0x37/0x6d0 [ 26.198134] RSP [ 26.201805] CR2: ffffeafff91a8020 [ 26.205246] ---[ end trace 6e47624da41c0124 ]--- [ 26.209985] Kernel panic - not syncing: Fatal exception [ 26.215604] Dumping ftrace buffer: [ 26.219126] (ftrace buffer empty) [ 26.222815] Kernel Offset: disabled [ 26.226424] Rebooting in 86400 seconds..