[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 12.131491] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.342983] random: sshd: uninitialized urandom read (32 bytes read) [ 21.707948] random: sshd: uninitialized urandom read (32 bytes read) [ 22.275995] random: sshd: uninitialized urandom read (32 bytes read) [ 49.524868] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.46' (ECDSA) to the list of known hosts. [ 54.963207] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 55.047827] IPVS: Creating netns size=2536 id=1 executing program executing program [ 55.201507] syz-executor529 (3829) used greatest stack depth: 23448 bytes left executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 59.746607] syz-executor529 (4218) used greatest stack depth: 23096 bytes left executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 61.839587] ------------[ cut here ]------------ [ 61.844369] kernel BUG at fs/ext4/inode.c:2630! [ 61.849021] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 61.854357] Dumping ftrace buffer: [ 61.857876] (ftrace buffer empty) [ 61.861559] Modules linked in: [ 61.864847] CPU: 1 PID: 4402 Comm: syz-executor529 Not tainted 4.9.100-ge14d1a3 #30 [ 61.872622] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 61.881949] task: ffff8801d72b3000 task.stack: ffff8801d55f8000 [ 61.887984] RIP: 0010:[] [] mpage_prepare_extent_to_map+0x7f8/0xa40 [ 61.897713] RSP: 0018:ffff8801d55ff3c0 EFLAGS: 00010293 [ 61.903131] RAX: ffff8801d72b3000 RBX: ffffea0007243d40 RCX: 0000000000000000 [ 61.910374] RDX: 0000000000000000 RSI: ffffffff8173cde8 RDI: ffffea0007243d48 [ 61.917614] RBP: ffff8801d55ff588 R08: ffff8801d72b3938 R09: 0000000000000001 [ 61.924856] R10: 0000000000000000 R11: 1ffff1003ae56722 R12: 0000000000000009 [ 61.932097] R13: 0000000000000000 R14: ffff8801d55ff6f0 R15: dffffc0000000000 [ 61.939353] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 61.947563] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 61.953423] CR2: 00007f59772d9e78 CR3: 000000000461e000 CR4: 00000000001606f0 [ 61.960688] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 61.967929] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 61.975172] Stack: [ 61.977294] 1ffff1003aabfe88 ffff8801d55ff6f8 ffff8801d55ff460 ffff8801d55ff700 [ 61.985304] 00000000d72b38c0 ffff8801c859a448 000000010000000c 7fffffffffffffff [ 61.993291] ffff8801d55ff4a0 ffff8801d55ff708 ffffea0007243d50 ffffed003aabfedf [ 62.001273] Call Trace: [ 62.003839] [] ? ext4_journalled_zero_new_buffers+0x3a0/0x3a0 [ 62.011348] [] ? __lock_is_held+0xa2/0xf0 [ 62.017128] [] ? __lock_is_held+0xa2/0xf0 [ 62.022919] [] ext4_writepages+0xdb9/0x2e50 [ 62.028953] [] ? do_writepages+0xef/0x1d0 [ 62.034725] [] ? __unwind_start+0x14d/0x3c0 [ 62.040676] [] ? unwind_next_frame+0x86/0xe0 [ 62.046706] [] ? ext4_mark_inode_dirty+0xb40/0xb40 [ 62.053254] [] ? __unwind_start+0x14d/0x3c0 [ 62.059198] [] ? depot_save_stack+0x132/0x460 [ 62.065325] [] ? ext4_mark_inode_dirty+0xb40/0xb40 [ 62.071873] [] do_writepages+0xef/0x1d0 [ 62.077468] [] ? page_writeback_cpu_online+0x20/0x20 [ 62.084204] [] ? exit_fs+0xe9/0x120 [ 62.089456] [] ? do_exit+0x9bb/0x27c0 [ 62.094888] [] ? do_group_exit+0x111/0x340 [ 62.100768] [] ? get_signal+0x4cf/0x1450 [ 62.106455] [] ? do_signal+0x87/0x19f0 [ 62.111965] [] ? exit_to_usermode_loop+0xe1/0x120 [ 62.118428] [] ? do_syscall_64+0x364/0x490 [ 62.124285] [] ? entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 62.131356] [] __filemap_fdatawrite_range+0x1b3/0x250 [ 62.138166] [] ? replace_page_cache_page+0x620/0x620 [ 62.144899] [] ? ext4_check_all_de+0xf0/0xf0 [ 62.150938] [] filemap_flush+0x23/0x30 [ 62.156445] [] ext4_alloc_da_blocks+0xd9/0x330 [ 62.162650] [] ext4_release_file+0x1ff/0x2e0 [ 62.168693] [] __fput+0x263/0x700 [ 62.173766] [] ____fput+0x15/0x20 [ 62.178841] [] task_work_run+0x10c/0x180 [ 62.184613] [] do_exit+0x9e1/0x27c0 [ 62.189873] [] ? debug_check_no_locks_freed+0x210/0x210 [ 62.196857] [] ? release_task.part.19+0x1210/0x1210 [ 62.203494] [] ? generic_file_read_iter+0x487/0x1a90 [ 62.210226] [] ? recalc_sigpending+0x72/0x90 [ 62.216257] [] do_group_exit+0x111/0x340 [ 62.221938] [] get_signal+0x4cf/0x1450 [ 62.227458] [] do_signal+0x87/0x19f0 [ 62.232893] [] ? __fsnotify_update_child_dentry_flags.part.1+0x300/0x300 [ 62.241353] [] ? selinux_file_permission+0x82/0x470 [ 62.247991] [] ? setup_sigcontext+0x7d0/0x7d0 [ 62.254119] [] ? do_futex+0x1770/0x1770 [ 62.259718] [] ? SyS_pread64+0xe8/0x170 [ 62.265314] [] ? exit_to_usermode_loop+0xac/0x120 [ 62.271779] [] exit_to_usermode_loop+0xe1/0x120 [ 62.278852] [] do_syscall_64+0x364/0x490 [ 62.284534] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 62.291432] Code: ff 48 8b 75 d0 65 48 33 34 25 28 00 00 00 0f 85 50 02 00 00 48 81 c4 a0 01 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 18 fc c1 ff <0f> 0b e8 11 fc c1 ff 8b 95 18 ff ff ff 85 d2 75 7a e8 02 fc c1 [ 62.295352] RIP [ 62.295359] [] mpage_prepare_extent_to_map+0x7f8/0xa40 RSP [ 62.299270] ---[ end trace c32b892075994e02 ]--- [ 62.299276] Kernel panic - not syncing: Fatal exception [ 62.300569] Dumping ftrace buffer: [ 62.300572] (ftrace buffer empty) [ 62.300574] Kernel Offset: disabled [ 62.343726] Rebooting in 86400 seconds..