[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.690982] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 18.382113] random: sshd: uninitialized urandom read (32 bytes read) [ 18.898605] random: sshd: uninitialized urandom read (32 bytes read) [ 19.340443] random: sshd: uninitialized urandom read (32 bytes read) [ 19.488934] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.29' (ECDSA) to the list of known hosts. [ 25.001602] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 25.083659] BUG: unable to handle kernel paging request at ffffeafff9078020 [ 25.091104] IP: [] page_remove_rmap+0x37/0x6d0 [ 25.097368] PGD 0 [ 25.099328] [ 25.101058] Oops: 0000 [#1] PREEMPT SMP KASAN [ 25.105638] Dumping ftrace buffer: [ 25.109168] (ftrace buffer empty) [ 25.112879] Modules linked in: [ 25.116181] CPU: 1 PID: 3780 Comm: syz-executor523 Not tainted 4.9.120-gf85543b #24 [ 25.123968] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 25.133324] task: ffff8801ba35c800 task.stack: ffff8801b7d30000 [ 25.139379] RIP: 0010:[] [] page_remove_rmap+0x37/0x6d0 [ 25.148064] RSP: 0018:ffff8801b7d37948 EFLAGS: 00010246 [ 25.153490] RAX: dffffc0000000000 RBX: ffffeafff9078000 RCX: ffffea0006f80000 [ 25.160738] RDX: 1ffffd5fff20f004 RSI: ffffffff814f5128 RDI: ffffeafff9078000 [ 25.168009] RBP: ffff8801b7d37970 R08: 0000000000033e00 R09: 0000000000000001 [ 25.175263] R10: ffff8801ba35c800 R11: 0000000000000001 R12: ffff8801b7d37c08 [ 25.182529] R13: ffffeafff9078020 R14: ffffeafff9078000 R15: 0000000000000001 [ 25.189780] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 25.198012] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 25.203872] CR2: ffffeafff9078020 CR3: 00000001bc60f000 CR4: 00000000001606f0 [ 25.211126] Stack: [ 25.213277] ffffeafff9078020 ffff8801b7d37c08 ffff8801bfbc4810 ffffeafff9078000 [ 25.221291] ffff8801b8652aa8 ffff8801b7d379c8 ffffffff8154bfcf ffff8801b7d37c18 [ 25.229284] ffff8801b7d37c10 ffff8801b7d37c88 00003ffe41e001a0 00000001bfbc4000 [ 25.237282] Call Trace: [ 25.239849] [] zap_huge_pmd+0x16f/0x860 [ 25.245451] [] unmap_page_range+0x12ad/0x1730 [ 25.251576] [] ? vm_normal_page_pmd+0x2f0/0x2f0 [ 25.257875] [] ? _raw_spin_unlock_irqrestore+0x5a/0x70 [ 25.264787] [] ? trace_hardirqs_on_caller+0x38b/0x590 [ 25.271623] [] unmap_single_vma+0x101/0x260 [ 25.277580] [] unmap_vmas+0x102/0x1d0 [ 25.283013] [] exit_mmap+0x214/0x3f0 [ 25.288357] [] ? SyS_munmap+0xa0/0xa0 [ 25.293796] [] ? up_write+0x1a/0x60 [ 25.299061] [] mmput+0xf3/0x2d0 [ 25.303975] [] do_exit+0x906/0x27b0 [ 25.309233] [] ? release_task.part.19+0x1210/0x1210 [ 25.315899] [] ? up_write+0x1a/0x60 [ 25.321161] [] ? do_mprotect_pkey+0x71d/0x890 [ 25.327286] [] ? mprotect_fixup+0x930/0x930 [ 25.333267] [] do_group_exit+0x111/0x340 [ 25.338987] [] ? do_group_exit+0x340/0x340 [ 25.344857] [] SyS_exit_group+0x1d/0x20 [ 25.350460] [] do_syscall_64+0x1a6/0x490 [ 25.356153] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.363053] 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 [ 25.390525] RIP [] page_remove_rmap+0x37/0x6d0 [ 25.396866] RSP [ 25.400465] CR2: ffffeafff9078020 [ 25.403896] ---[ end trace 951855b98abc3cef ]--- [ 25.408626] Kernel panic - not syncing: Fatal exception [ 25.414315] Dumping ftrace buffer: [ 25.417834] (ftrace buffer empty) [ 25.421521] Kernel Offset: disabled [ 25.425129] Rebooting in 86400 seconds..