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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: 4706 Comm: syz-executor169 Not tainted 4.4.132-g4f75c34 #44
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800b9906000 task.stack: ffff8800b9908000
RIP: 0010:[<ffffffff816d736f>]  [<ffffffff816d736f>] mpage_prepare_extent_to_map+0x74f/0x970 fs/ext4/inode.c:2474
RSP: 0018:ffff8800b990f410  EFLAGS: 00010293
RAX: ffff8800b9906000 RBX: ffffea00028fe200 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff816d736f RDI: ffffea00028fe208
RBP: ffff8800b990f5d8 R08: ffff8800b9906928 R09: 0000000000000001
R10: 0000000000000000 R11: ffff8800b9906000 R12: 0000000000000007
R13: 0000000000000000 R14: ffff8800b990f720 R15: dffffc0000000000
FS:  00007f28f6590700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f28f658fe78 CR3: 000000000440c000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8800b990f538 1ffff10017321e92 ffff8800b990f728 ffff8800b990f4b0
 ffff8800b990f730 00000000b6bc0968 ffff8800ac43f3d8 000000030000000c
 7fffffffffffffff ffff8800b990f4f0 ffff8800b990f738 ffffea00028fe210
Call Trace:
 [<ffffffff816e9250>] ext4_writepages+0xbb0/0x2c80 fs/ext4/inode.c:2629
 [<ffffffff8143fdbf>] do_writepages+0xef/0x1d0 mm/page-writeback.c:2350
 [<ffffffff814223c3>] __filemap_fdatawrite_range+0x1b3/0x250 mm/filemap.c:347
 [<ffffffff814225e3>] __filemap_fdatawrite mm/filemap.c:355 [inline]
 [<ffffffff814225e3>] filemap_flush+0x23/0x30 mm/filemap.c:380
 [<ffffffff816df258>] ext4_alloc_da_blocks+0x108/0x3c0 fs/ext4/inode.c:3005
 [<ffffffff816c3c4f>] ext4_release_file+0x1ff/0x2e0 fs/ext4/file.c:42
 [<ffffffff81522655>] __fput+0x235/0x6f0 fs/file_table.c:208
 [<ffffffff81522b95>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8118bb8f>] task_work_run+0x10f/0x190 kernel/task_work.c:115
 [<ffffffff81135175>] exit_task_work include/linux/task_work.h:21 [inline]
 [<ffffffff81135175>] do_exit+0x9e5/0x26b0 kernel/exit.c:759
 [<ffffffff8113b0c1>] do_group_exit+0x111/0x330 kernel/exit.c:889
 [<ffffffff8115e45c>] get_signal+0x4ec/0x14b0 kernel/signal.c:2317
 [<ffffffff8100e02b>] do_signal+0x8b/0x1d30 arch/x86/kernel/signal.c:712
 [<ffffffff8100360a>] exit_to_usermode_loop+0x11a/0x160 arch/x86/entry/common.c:248
 [<ffffffff81006535>] prepare_exit_to_usermode arch/x86/entry/common.c:283 [inline]
 [<ffffffff81006535>] syscall_return_slowpath+0x1b5/0x1f0 arch/x86/entry/common.c:348
 [<ffffffff838c03b5>] int_ret_from_sys_call+0x25/0xa3
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 
RIP  [<ffffffff816d736f>] mpage_prepare_extent_to_map+0x74f/0x970 fs/ext4/inode.c:2474
 RSP <ffff8800b990f410>
---[ end trace 7e647c8f011ae402 ]---