[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 10.084052] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 13.588022] random: sshd: uninitialized urandom read (32 bytes read) [ 13.798659] random: sshd: uninitialized urandom read (32 bytes read) [ 14.291232] random: sshd: uninitialized urandom read (32 bytes read) [ 14.412611] random: crng init done Warning: Permanently added '10.128.10.11' (ECDSA) to the list of known hosts. 2018/09/01 02:15:38 parsed 1 programs 2018/09/01 02:15:39 executed programs: 0 2018/09/01 02:15:45 executed programs: 8 [ 42.704506] syz-executor4 (5732) used greatest stack depth: 23720 bytes left [ 42.728008] syz-executor4 (5783) used greatest stack depth: 23368 bytes left [ 43.369825] syz-executor5 (6039) used greatest stack depth: 23112 bytes left [ 44.515671] syz-executor6 (6441) used greatest stack depth: 22984 bytes left 2018/09/01 02:15:50 executed programs: 188 [ 48.744565] syz-executor2 (7784) used greatest stack depth: 22360 bytes left 2018/09/01 02:15:55 executed programs: 365 2018/09/01 02:16:00 executed programs: 545 2018/09/01 02:16:05 executed programs: 727 [ 65.280604] ------------[ cut here ]------------ [ 65.285397] kernel BUG at fs/ext4/inode.c:2618! [ 65.290064] invalid opcode: 0000 [#1] PREEMPT SMP KASAN [ 65.295416] Dumping ftrace buffer: [ 65.298947] (ftrace buffer empty) [ 65.302654] Modules linked in: [ 65.305974] CPU: 1 PID: 2234 Comm: syz-executor3 Not tainted 4.9.124+ #33 [ 65.312898] task: ffff8801c10217c0 task.stack: ffff8801c1768000 [ 65.318952] RIP: 0010:[] [] mpage_prepare_extent_to_map+0x719/0x9a0 [ 65.328712] RSP: 0018:ffff8801c176f688 EFLAGS: 00010293 [ 65.334154] RAX: ffff8801c10217c0 RBX: ffffea0007203a40 RCX: 0000000000000000 [ 65.341423] RDX: 0000000000000000 RSI: ffffffff8169fd29 RDI: ffffea0007203a50 [ 65.348692] RBP: ffff8801c176f848 R08: ffff8801c1022070 R09: 0000000000000001 [ 65.355955] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 [ 65.363210] R13: 0000000000000002 R14: dffffc0000000000 R15: ffff8801c176f9b0 [ 65.370463] FS: 000000000200c940(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000 [ 65.378680] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 65.384543] CR2: 00000000004d72c0 CR3: 00000001cb6c9000 CR4: 00000000001606b0 [ 65.391801] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 65.399072] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 65.406327] Stack: [ 65.408453] 1ffff100382edee0 ffff8801c176f720 ffff8801c176f9b8 ffff8801c176f9c0 [ 65.416493] 0000000200000246 0007ffffffffffff ffff8801c896f4c8 000000080000000c [ 65.424492] 7fffffffffffffff ffff8801c176f760 ffff8801c176f9c8 ffffed00382edf37 [ 65.432538] Call Trace: [ 65.435104] [] ? mpage_process_page_bufs+0x490/0x490 [ 65.441840] [] ? check_preemption_disabled+0x3b/0x170 [ 65.448669] [] ext4_writepages+0xeee/0x2e00 [ 65.454632] [] ? do_writepages+0xef/0x1d0 [ 65.460419] [] ? __ext4_journal_stop+0xd1/0x1c0 [ 65.466728] [] ? do_syscall_64+0x19f/0x480 [ 65.472595] [] ? entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 65.479685] [] ? ext4_mark_inode_dirty+0xb40/0xb40 [ 65.486253] [] ? _raw_spin_unlock_irqrestore+0x45/0x70 [ 65.493161] [] ? __lock_acquire+0x654/0x4a10 [ 65.499206] [] ? ext4_mark_inode_dirty+0xb40/0xb40 [ 65.505819] [] do_writepages+0xef/0x1d0 [ 65.511448] [] ? page_writeback_cpu_online+0x20/0x20 [ 65.518203] [] ? trace_hardirqs_on+0x10/0x10 [ 65.524246] [] __filemap_fdatawrite_range+0x1a9/0x250 [ 65.531073] [] ? replace_page_cache_page+0x600/0x600 [ 65.537826] [] ? jbd2_journal_begin_ordered_truncate+0x9a/0x190 [ 65.545524] [] ? jbd2_journal_begin_ordered_truncate+0xc0/0x190 [ 65.553226] [] filemap_fdatawrite_range+0x2a/0x40 [ 65.559706] [] jbd2_journal_begin_ordered_truncate+0x133/0x190 [ 65.567366] [] ext4_evict_inode+0xd68/0x1230 [ 65.573465] [] ? _raw_spin_unlock+0x2c/0x50 [ 65.579433] [] ? ext4_journalled_write_end+0x1230/0x1230 [ 65.586519] [] evict+0x22e/0x4f0 [ 65.591519] [] ? ext4_statfs+0xbb0/0xbb0 [ 65.597217] [] iput+0x371/0x900 [ 65.602125] [] do_unlinkat+0x4d5/0x660 [ 65.607638] [] ? do_rmdir+0x3b0/0x3b0 [ 65.613065] [] ? SyS_umount+0x1b4/0xb90 [ 65.618665] [] ? SyS_newlstat+0x9b/0x100 [ 65.624383] [] ? SyS_newstat+0xf0/0xf0 [ 65.629912] [] ? do_syscall_64+0x48/0x480 [ 65.635689] [] ? SyS_unlinkat+0x80/0x80 [ 65.641292] [] SyS_unlink+0x1a/0x20 [ 65.646544] [] do_syscall_64+0x19f/0x480 [ 65.652262] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 65.659195] Code: fc ff ff 48 89 95 b0 fe ff ff e8 23 cb c6 ff 48 8b 95 b0 fe ff ff 48 8d 42 ff e9 6f ff ff ff e8 0e cb c6 ff 0f 0b e8 07 cb c6 ff <0f> 0b 31 c0 89 85 b0 fe ff ff e8 f8 ca c6 ff 8b 85 18 ff ff ff [ 65.686464] RIP [] mpage_prepare_extent_to_map+0x719/0x9a0 [ 65.693879] RSP [ 65.698603] ---[ end trace 89d721143278b22d ]--- [ 65.703571] Kernel panic - not syncing: Fatal exception [ 65.709263] Dumping ftrace buffer: [ 65.712806] (ftrace buffer empty) [ 65.716509] Kernel Offset: disabled [ 65.720112] Rebooting in 86400 seconds..