random: nonblocking pool is initialized IPVS: Creating netns size=2552 id=1 syz-executor0 (3914) used greatest stack depth: 23424 bytes left syz-executor0 (3962) used greatest stack depth: 23120 bytes left ------------[ cut here ]------------ kernel BUG at fs/ext4/inode.c:2474! invalid opcode: 0000 [#1] PREEMPT SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 4323 Comm: syz-executor0 Not tainted 4.4.140-ged9bdc8 #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801d3f99800 task.stack: ffff8800b64a0000 RIP: 0010:[] [] mpage_prepare_extent_to_map+0x74f/0x970 fs/ext4/inode.c:2474 RSP: 0018:ffff8800b64a77e0 EFLAGS: 00010293 RAX: ffff8801d3f99800 RBX: ffffea00070ae100 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff816d7fcf RDI: ffffea00070ae108 RBP: ffff8800b64a79a8 R08: ffff8801d3f9a128 R09: 0000000000000001 R10: 0000000000000000 R11: ffff8801d3f99800 R12: 0000000000000001 R13: 0000000000000000 R14: ffff8800b64a7af0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8801db200000(0063) knlGS:000000000892e900 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000000814b009 CR3: 00000000b754c000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff8800b64a7908 1ffff10016c94f0c ffff8800b64a7af8 ffff8800b64a7880 ffff8800b64a7b00 00000000d3473c68 ffff8800ab5653d8 000000090000000c 7fffffffffffffff ffff8800b64a78c0 ffff8800b64a7b08 ffffea00070ae110 Call Trace: [] ext4_writepages+0xbb0/0x2c80 fs/ext4/inode.c:2629 [] do_writepages+0xef/0x1d0 mm/page-writeback.c:2350 [] __filemap_fdatawrite_range+0x1b3/0x250 mm/filemap.c:347 [] __filemap_fdatawrite mm/filemap.c:355 [inline] [] filemap_flush+0x23/0x30 mm/filemap.c:380 [] ext4_alloc_da_blocks+0x108/0x3c0 fs/ext4/inode.c:3005 [] ext4_release_file+0x1ff/0x2e0 fs/ext4/file.c:42 [] __fput+0x235/0x6f0 fs/file_table.c:208 [] ____fput+0x15/0x20 fs/file_table.c:244 [] task_work_run+0x10f/0x190 kernel/task_work.c:115 [] tracehook_notify_resume include/linux/tracehook.h:191 [inline] [] exit_to_usermode_loop+0x13d/0x160 arch/x86/entry/common.c:252 [] prepare_exit_to_usermode arch/x86/entry/common.c:283 [inline] [] syscall_return_slowpath arch/x86/entry/common.c:348 [inline] [] do_syscall_32_irqs_on arch/x86/entry/common.c:398 [inline] [] do_fast_syscall_32+0x620/0x8b0 arch/x86/entry/common.c:459 [] sysenter_flags_fixed+0xd/0x17 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 21 95 c7 ff <0f> 0b e8 1a 95 c7 ff 8b 95 18 ff ff ff 85 d2 75 7f e8 0b 95 c7 RIP [] mpage_prepare_extent_to_map+0x74f/0x970 fs/ext4/inode.c:2474 RSP ---[ end trace ab4668f08f63fb58 ]---