[....] 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[ 12.599881] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.144051] random: sshd: uninitialized urandom read (32 bytes read) [ 21.381889] random: sshd: uninitialized urandom read (32 bytes read) [ 21.883231] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.24' (ECDSA) to the list of known hosts. [ 27.741450] urandom_read: 1 callbacks suppressed [ 27.741454] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 27.828363] BUG: unable to handle kernel paging request at ffffeafff9108020 [ 27.835730] IP: [] page_remove_rmap+0x37/0x6d0 [ 27.841975] PGD 0 [ 27.843921] [ 27.845545] Oops: 0000 [#1] PREEMPT SMP KASAN [ 27.850016] Dumping ftrace buffer: [ 27.853530] (ftrace buffer empty) [ 27.857325] Modules linked in: [ 27.860620] CPU: 1 PID: 3795 Comm: syz-executor168 Not tainted 4.9.120-gf85543b #76 [ 27.868455] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.877794] task: ffff8801b5c58000 task.stack: ffff8801b6340000 [ 27.883826] RIP: 0010:[] [] page_remove_rmap+0x37/0x6d0 [ 27.892552] RSP: 0018:ffff8801b6347948 EFLAGS: 00010246 [ 27.897994] RAX: dffffc0000000000 RBX: ffffeafff9108000 RCX: ffffea0006d28000 [ 27.905239] RDX: 1ffffd5fff221004 RSI: ffffffff814f5128 RDI: ffffeafff9108000 [ 27.912482] RBP: ffff8801b6347970 R08: 0000000000033b40 R09: 0000000000000001 [ 27.919727] R10: ffff8801b5c58000 R11: 0000000000000001 R12: ffff8801b6347c08 [ 27.926972] R13: ffffeafff9108020 R14: ffffeafff9108000 R15: 0000000000000001 [ 27.934220] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 27.942420] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 27.948281] CR2: ffffeafff9108020 CR3: 00000001cb3ea000 CR4: 00000000001606f0 [ 27.955720] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 27.963096] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 27.970346] Stack: [ 27.972470] ffffeafff9108020 ffff8801b6347c08 ffff8801c9cc5808 ffffeafff9108000 [ 27.980496] ffff8801b5e12268 ffff8801b63479c8 ffffffff8154bfcf ffff8801b6347c18 [ 27.988556] ffff8801b6347c10 ffff8801b6347c88 00003ffe442001e0 ffff8801b6347ae8 [ 27.996557] Call Trace: [ 27.999123] [] zap_huge_pmd+0x16f/0x860 [ 28.004727] [] unmap_page_range+0x12ad/0x1730 [ 28.010852] [] ? vm_normal_page_pmd+0x2f0/0x2f0 [ 28.017146] [] unmap_single_vma+0x101/0x260 [ 28.023094] [] unmap_vmas+0x102/0x1d0 [ 28.028518] [] exit_mmap+0x214/0x3f0 [ 28.033854] [] ? SyS_munmap+0xa0/0xa0 [ 28.039278] [] ? up_write+0x1a/0x60 [ 28.044619] [] mmput+0xf3/0x2d0 [ 28.049525] [] do_exit+0x906/0x27b0 [ 28.054778] [] ? release_task.part.19+0x1210/0x1210 [ 28.061418] [] ? up_write+0x1a/0x60 [ 28.066671] [] ? do_mprotect_pkey+0x71d/0x890 [ 28.072803] [] ? mprotect_fixup+0x930/0x930 [ 28.078749] [] do_group_exit+0x111/0x340 [ 28.084440] [] ? do_group_exit+0x340/0x340 [ 28.090302] [] SyS_exit_group+0x1d/0x20 [ 28.095906] [] do_syscall_64+0x1a6/0x490 [ 28.101594] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 28.108498] 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 [ 28.135473] RIP [] page_remove_rmap+0x37/0x6d0 [ 28.141820] RSP [ 28.145419] CR2: ffffeafff9108020 [ 28.148850] ---[ end trace 7ad5ab9e6da9a3b2 ]--- [ 28.153577] Kernel panic - not syncing: Fatal exception [ 28.159308] Dumping ftrace buffer: [ 28.162832] (ftrace buffer empty) [ 28.166516] Kernel Offset: disabled [ 28.170116] Rebooting in 86400 seconds..