[....] 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[ 16.018301] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 18.229932] random: sshd: uninitialized urandom read (32 bytes read) [ 18.542205] random: sshd: uninitialized urandom read (32 bytes read) [ 19.039359] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.4' (ECDSA) to the list of known hosts. [ 24.655947] urandom_read: 1 callbacks suppressed [ 24.655950] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 24.747692] BUG: unable to handle kernel paging request at ffffeafff9198020 [ 24.755133] IP: [] page_remove_rmap+0x37/0x6d0 [ 24.761386] PGD 0 [ 24.763336] [ 24.764958] Oops: 0000 [#1] PREEMPT SMP KASAN [ 24.769523] Dumping ftrace buffer: [ 24.773123] (ftrace buffer empty) [ 24.776812] Modules linked in: [ 24.780118] CPU: 0 PID: 3795 Comm: syz-executor705 Not tainted 4.9.121-g681e57b #25 [ 24.787880] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.797211] task: ffff8801b5980000 task.stack: ffff8801b7410000 [ 24.803244] RIP: 0010:[] [] page_remove_rmap+0x37/0x6d0 [ 24.812070] RSP: 0018:ffff8801b7417948 EFLAGS: 00010246 [ 24.817495] RAX: dffffc0000000000 RBX: ffffeafff9198000 RCX: 0000000000000000 [ 24.824836] RDX: 1ffffd5fff233004 RSI: ffffffff814f5278 RDI: ffffeafff9198000 [ 24.832093] RBP: ffff8801b7417970 R08: 00000000000337c0 R09: 0000000000000001 [ 24.839346] R10: ffff8801b5980000 R11: 0000000000000001 R12: ffff8801b7417c08 [ 24.846718] R13: ffffeafff9198020 R14: ffffeafff9198000 R15: 0000000000000001 [ 24.853979] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 24.862256] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 24.868115] CR2: ffffeafff9198020 CR3: 00000001c9867000 CR4: 00000000001606f0 [ 24.875479] Stack: [ 24.877645] ffffeafff9198020 ffff8801b7417c08 ffff8801c994a800 ffffeafff9198000 [ 24.885651] ffff8801b5b06d10 ffff8801b74179c8 ffffffff8154c20f ffff8801b7417c18 [ 24.893681] ffff8801b7417c10 ffff8801b7417c88 00003ffe466001e0 00000001c994a000 [ 24.901674] Call Trace: [ 24.904237] [] zap_huge_pmd+0x16f/0x860 [ 24.909837] [] unmap_page_range+0x12ad/0x1730 [ 24.915954] [] ? vm_normal_page_pmd+0x2f0/0x2f0 [ 24.922248] [] unmap_single_vma+0x101/0x260 [ 24.928193] [] unmap_vmas+0x102/0x1d0 [ 24.933621] [] exit_mmap+0x214/0x3f0 [ 24.938962] [] ? SyS_munmap+0xa0/0xa0 [ 24.944395] [] ? up_write+0x1a/0x60 [ 24.949650] [] mmput+0xf3/0x2d0 [ 24.954620] [] do_exit+0x906/0x27b0 [ 24.959946] [] ? release_task.part.19+0x1210/0x1210 [ 24.966610] [] ? up_write+0x1a/0x60 [ 24.971862] [] ? do_mprotect_pkey+0x71d/0x890 [ 24.978089] [] ? mprotect_fixup+0x930/0x930 [ 24.984060] [] do_group_exit+0x111/0x340 [ 24.989745] [] ? do_group_exit+0x340/0x340 [ 24.995715] [] SyS_exit_group+0x1d/0x20 [ 25.001440] [] do_syscall_64+0x1a6/0x490 [ 25.007148] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 25.014044] 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 [ 25.041242] RIP [] page_remove_rmap+0x37/0x6d0 [ 25.047569] RSP [ 25.051166] CR2: ffffeafff9198020 [ 25.054608] ---[ end trace 01363e3e91f95cd3 ]--- [ 25.059332] Kernel panic - not syncing: Fatal exception [ 25.064987] Dumping ftrace buffer: [ 25.068514] (ftrace buffer empty) [ 25.072197] Kernel Offset: disabled [ 25.075886] Rebooting in 86400 seconds..