[....] 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[ 13.854479] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.278021] random: sshd: uninitialized urandom read (32 bytes read) [ 22.572169] random: sshd: uninitialized urandom read (32 bytes read) [ 23.104794] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.50' (ECDSA) to the list of known hosts. [ 28.890011] urandom_read: 1 callbacks suppressed [ 28.890014] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 28.973563] BUG: unable to handle kernel paging request at ffffeafff91e0020 [ 28.980929] IP: [] page_remove_rmap+0x37/0x6d0 [ 28.987189] PGD 0 [ 28.989134] [ 28.990753] Oops: 0000 [#1] PREEMPT SMP KASAN [ 28.995219] Dumping ftrace buffer: [ 28.998732] (ftrace buffer empty) [ 29.002425] Modules linked in: [ 29.005713] CPU: 1 PID: 3806 Comm: syz-executor002 Not tainted 4.9.121-g681e57b #25 [ 29.013479] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.022833] task: ffff8801b63a8000 task.stack: ffff8801b7930000 [ 29.028862] RIP: 0010:[] [] page_remove_rmap+0x37/0x6d0 [ 29.037544] RSP: 0018:ffff8801b7937948 EFLAGS: 00010246 [ 29.042978] RAX: dffffc0000000000 RBX: ffffeafff91e0000 RCX: 0000000000000000 [ 29.050236] RDX: 1ffffd5fff23c004 RSI: ffffffff814f5278 RDI: ffffeafff91e0000 [ 29.057484] RBP: ffff8801b7937970 R08: 00000000000340a0 R09: 0000000000000001 [ 29.064740] R10: ffff8801b63a8000 R11: 0000000000000001 R12: ffff8801b7937c08 [ 29.071984] R13: ffffeafff91e0020 R14: ffffeafff91e0000 R15: 0000000000000001 [ 29.079288] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 29.087494] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.093355] CR2: ffffeafff91e0020 CR3: 00000001c8e2a000 CR4: 00000000001606f0 [ 29.100603] Stack: [ 29.102728] ffffeafff91e0020 ffff8801b7937c08 ffff8801c9a08800 ffffeafff91e0000 [ 29.110712] ffff8801c8f3eaa8 ffff8801b79379c8 ffffffff8154c20f ffff8801b7937c18 [ 29.118702] ffff8801b7937c10 ffff8801b7937c88 00003ffe478001e0 00000001c9a08000 [ 29.126702] Call Trace: [ 29.129280] [] zap_huge_pmd+0x16f/0x860 [ 29.134901] [] unmap_page_range+0x12ad/0x1730 [ 29.141022] [] ? vm_normal_page_pmd+0x2f0/0x2f0 [ 29.147322] [] unmap_single_vma+0x101/0x260 [ 29.153270] [] unmap_vmas+0x102/0x1d0 [ 29.158693] [] exit_mmap+0x214/0x3f0 [ 29.164028] [] ? SyS_munmap+0xa0/0xa0 [ 29.169453] [] ? up_write+0x1a/0x60 [ 29.174702] [] mmput+0xf3/0x2d0 [ 29.179610] [] do_exit+0x906/0x27b0 [ 29.184886] [] ? release_task.part.19+0x1210/0x1210 [ 29.191646] [] ? up_write+0x1a/0x60 [ 29.196946] [] ? do_mprotect_pkey+0x71d/0x890 [ 29.203080] [] ? mprotect_fixup+0x930/0x930 [ 29.209027] [] do_group_exit+0x111/0x340 [ 29.214711] [] ? do_group_exit+0x340/0x340 [ 29.220574] [] SyS_exit_group+0x1d/0x20 [ 29.226180] [] do_syscall_64+0x1a6/0x490 [ 29.231877] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 29.238775] 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 [ 29.265800] RIP [] page_remove_rmap+0x37/0x6d0 [ 29.272128] RSP [ 29.275724] CR2: ffffeafff91e0020 [ 29.279153] ---[ end trace e689ad1881d2397b ]--- [ 29.283887] Kernel panic - not syncing: Fatal exception [ 29.289558] Dumping ftrace buffer: [ 29.293082] (ftrace buffer empty) [ 29.296769] Kernel Offset: disabled [ 29.300374] Rebooting in 86400 seconds..