[....] 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[ 21.323185] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[ ok 8[?25h[?0c. [ 22.375161] random: sshd: uninitialized urandom read (32 bytes read, 34 bits of entropy available) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.831011] random: sshd: uninitialized urandom read (32 bytes read, 35 bits of entropy available) [ 23.876631] random: nonblocking pool is initialized Warning: Permanently added '10.128.0.22' (ECDSA) to the list of known hosts. executing program [ 35.329065] IPVS: Creating netns size=2552 id=1 executing program executing program executing program executing program executing program [ 35.517238] syz-executor169 (3838) used greatest stack depth: 23792 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 40.037374] syz-executor169 (4268) used greatest stack depth: 23712 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 [ 42.231479] syz-executor169 (4475) used greatest stack depth: 23312 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 [ 44.661569] ------------[ cut here ]------------ [ 44.666325] kernel BUG at fs/ext4/inode.c:2474! [ 44.670964] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 44.676764] Dumping ftrace buffer: [ 44.680275] (ftrace buffer empty) [ 44.683974] Modules linked in: [ 44.687255] CPU: 0 PID: 4706 Comm: syz-executor169 Not tainted 4.4.132-g4f75c34 #44 [ 44.695014] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.704339] task: ffff8800b9906000 task.stack: ffff8800b9908000 [ 44.710363] RIP: 0010:[] [] mpage_prepare_extent_to_map+0x74f/0x970 [ 44.720079] RSP: 0018:ffff8800b990f410 EFLAGS: 00010293 [ 44.725494] RAX: ffff8800b9906000 RBX: ffffea00028fe200 RCX: 0000000000000000 [ 44.732733] RDX: 0000000000000000 RSI: ffffffff816d736f RDI: ffffea00028fe208 [ 44.739974] RBP: ffff8800b990f5d8 R08: ffff8800b9906928 R09: 0000000000000001 [ 44.747215] R10: 0000000000000000 R11: ffff8800b9906000 R12: 0000000000000007 [ 44.754454] R13: 0000000000000000 R14: ffff8800b990f720 R15: dffffc0000000000 [ 44.761696] FS: 00007f28f6590700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 44.769895] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 44.775747] CR2: 00007f28f658fe78 CR3: 000000000440c000 CR4: 00000000001606f0 [ 44.782990] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 44.790229] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 44.797467] Stack: [ 44.799586] ffff8800b990f538 1ffff10017321e92 ffff8800b990f728 ffff8800b990f4b0 [ 44.807561] ffff8800b990f730 00000000b6bc0968 ffff8800ac43f3d8 000000030000000c [ 44.815533] 7fffffffffffffff ffff8800b990f4f0 ffff8800b990f738 ffffea00028fe210 [ 44.823503] Call Trace: [ 44.826071] [] ? ext4_journalled_zero_new_buffers+0x350/0x350 [ 44.833575] [] ? __lock_is_held+0xa2/0xf0 [ 44.839342] [] ? rcu_read_lock_sched_held+0x103/0x120 [ 44.846150] [] ? __lock_is_held+0xa2/0xf0 [ 44.851915] [] ext4_writepages+0xbb0/0x2c80 [ 44.857859] [] ? dump_trace+0x184/0x360 [ 44.863454] [] ? ext4_mark_inode_dirty+0xb80/0xb80 [ 44.870002] [] ? print_context_stack+0x4b/0xd0 [ 44.876207] [] ? depot_save_stack+0x1c9/0x610 [ 44.882321] [] ? ext4_mark_inode_dirty+0xb80/0xb80 [ 44.888871] [] do_writepages+0xef/0x1d0 [ 44.894466] [] ? ratelimit_handler+0x50/0x50 [ 44.900495] [] ? do_group_exit+0x111/0x330 [ 44.906349] [] ? get_signal+0x4ec/0x14b0 [ 44.912030] [] ? do_signal+0x8b/0x1d30 [ 44.917541] [] ? exit_to_usermode_loop+0x11a/0x160 [ 44.924088] [] ? syscall_return_slowpath+0x1b5/0x1f0 [ 44.930812] [] ? int_ret_from_sys_call+0x25/0xa3 [ 44.937187] [] __filemap_fdatawrite_range+0x1b3/0x250 [ 44.943995] [] ? replace_page_cache_page+0x440/0x440 [ 44.950714] [] ? ext4_check_all_de+0xf0/0xf0 [ 44.956741] [] filemap_flush+0x23/0x30 [ 44.962245] [] ext4_alloc_da_blocks+0x108/0x3c0 [ 44.968535] [] ? ext4_check_all_de+0xf0/0xf0 [ 44.974561] [] ext4_release_file+0x1ff/0x2e0 [ 44.980591] [] __fput+0x235/0x6f0 [ 44.985661] [] ____fput+0x15/0x20 [ 44.990742] [] task_work_run+0x10f/0x190 [ 44.996419] [] do_exit+0x9e5/0x26b0 [ 45.001668] [] ? debug_check_no_locks_freed+0x210/0x210 [ 45.008648] [] ? get_futex_key+0xd80/0xd80 [ 45.014501] [] ? release_task.part.17+0x1200/0x1200 [ 45.021136] [] ? recalc_sigpending+0x76/0xa0 [ 45.027166] [] do_group_exit+0x111/0x330 [ 45.032845] [] get_signal+0x4ec/0x14b0 [ 45.038353] [] ? iov_iter_init+0xaf/0x1d0 [ 45.044119] [] do_signal+0x8b/0x1d30 [ 45.049452] [] ? vfs_iter_write+0x2d0/0x2d0 [ 45.055400] [] ? __fsnotify_update_child_dentry_flags.part.2+0x300/0x300 [ 45.063856] [] ? setup_sigcontext+0x780/0x780 [ 45.069969] [] ? __fsnotify_update_child_dentry_flags.part.2+0x300/0x300 [ 45.078437] [] ? selinux_file_permission+0x2f2/0x450 [ 45.085156] [] ? fsnotify+0x10c0/0x10c0 [ 45.090751] [] ? SyS_futex+0x1f8/0x300 [ 45.096258] [] ? exit_to_usermode_loop+0xe4/0x160 [ 45.102721] [] exit_to_usermode_loop+0x11a/0x160 [ 45.109096] [] syscall_return_slowpath+0x1b5/0x1f0 [ 45.115644] [] int_ret_from_sys_call+0x25/0xa3 [ 45.121843] Code: ff 48 8b 75 d0 65 48 33 34 25 28 00 00 00 0f 85 2e 02 00 00 48 81 c4 a0 01 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 71 9e c7 ff <0f> 0b e8 6a 9e c7 ff 8b 95 18 ff ff ff 85 d2 75 7f e8 5b 9e c7 [ 45.148489] RIP [] mpage_prepare_extent_to_map+0x74f/0x970 [ 45.155851] RSP [ 45.159530] ---[ end trace 7e647c8f011ae402 ]--- [ 45.164298] Kernel panic - not syncing: Fatal exception [ 45.170045] Dumping ftrace buffer: [ 45.173559] (ftrace buffer empty) [ 45.177241] Kernel Offset: disabled [ 45.180837] Rebooting in 86400 seconds..