[....] 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[ 15.943330] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.602145] random: sshd: uninitialized urandom read (32 bytes read) [ 21.001874] random: sshd: uninitialized urandom read (32 bytes read) [ 21.455071] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.25' (ECDSA) to the list of known hosts. [ 27.147148] urandom_read: 1 callbacks suppressed [ 27.147152] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 27.234319] BUG: unable to handle kernel paging request at ffffeafff90f8020 [ 27.241789] IP: [] page_remove_rmap+0x37/0x6d0 [ 27.248035] PGD 0 [ 27.249979] [ 27.251597] Oops: 0000 [#1] PREEMPT SMP KASAN [ 27.256063] Dumping ftrace buffer: [ 27.259633] (ftrace buffer empty) [ 27.263326] Modules linked in: [ 27.266620] CPU: 1 PID: 3796 Comm: syz-executor036 Not tainted 4.9.120-gf85543b #76 [ 27.274385] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.283826] task: ffff8801b884c800 task.stack: ffff8801b6138000 [ 27.289860] RIP: 0010:[] [] page_remove_rmap+0x37/0x6d0 [ 27.298582] RSP: 0018:ffff8801b613f948 EFLAGS: 00010246 [ 27.304012] RAX: dffffc0000000000 RBX: ffffeafff90f8000 RCX: 0000000000000000 [ 27.311254] RDX: 1ffffd5fff21f004 RSI: ffffffff814f5128 RDI: ffffeafff90f8000 [ 27.318563] RBP: ffff8801b613f970 R08: 00000000000339a0 R09: 0000000000000001 [ 27.325815] R10: ffff8801b884c800 R11: 0000000000000001 R12: ffff8801b613fc08 [ 27.333064] R13: ffffeafff90f8020 R14: ffffeafff90f8000 R15: 0000000000000001 [ 27.340314] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 27.348513] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 27.354372] CR2: ffffeafff90f8020 CR3: 00000001b65fe000 CR4: 00000000001606f0 [ 27.361624] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 27.368872] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 27.376117] Stack: [ 27.378245] ffffeafff90f8020 ffff8801b613fc08 ffff8801b7fa3800 ffffeafff90f8000 [ 27.386239] ffff8801b86a2c08 ffff8801b613f9c8 ffffffff8154bfcf ffff8801b613fc18 [ 27.394233] ffff8801b613fc10 ffff8801b613fc88 00003ffe43e001e0 00000001b7fa3000 [ 27.402329] Call Trace: [ 27.404895] [] zap_huge_pmd+0x16f/0x860 [ 27.410542] [] unmap_page_range+0x12ad/0x1730 [ 27.416670] [] ? vm_normal_page_pmd+0x2f0/0x2f0 [ 27.423009] [] unmap_single_vma+0x101/0x260 [ 27.428961] [] unmap_vmas+0x102/0x1d0 [ 27.434388] [] exit_mmap+0x214/0x3f0 [ 27.439725] [] ? SyS_munmap+0xa0/0xa0 [ 27.445153] [] ? up_write+0x1a/0x60 [ 27.450403] [] mmput+0xf3/0x2d0 [ 27.455306] [] do_exit+0x906/0x27b0 [ 27.460557] [] ? release_task.part.19+0x1210/0x1210 [ 27.467202] [] ? up_write+0x1a/0x60 [ 27.472449] [] ? do_mprotect_pkey+0x71d/0x890 [ 27.478567] [] ? mprotect_fixup+0x930/0x930 [ 27.484513] [] do_group_exit+0x111/0x340 [ 27.490299] [] ? do_group_exit+0x340/0x340 [ 27.496161] [] SyS_exit_group+0x1d/0x20 [ 27.501761] [] do_syscall_64+0x1a6/0x490 [ 27.507451] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 27.514350] 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 [ 27.541259] RIP [] page_remove_rmap+0x37/0x6d0 [ 27.547587] RSP [ 27.551181] CR2: ffffeafff90f8020 [ 27.554609] ---[ end trace 8d9a7d3b66fd9c64 ]--- [ 27.559340] Kernel panic - not syncing: Fatal exception [ 27.565061] Dumping ftrace buffer: [ 27.568582] (ftrace buffer empty) [ 27.572269] Kernel Offset: disabled [ 27.575879] Rebooting in 86400 seconds..