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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: 3765 Comm: syz-executor170 Not tainted 4.4.132-g4f75c34 #43
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d95d8000 task.stack: ffff8801d9688000
RIP: 0010:[<ffffffff816d736f>]  [<ffffffff816d736f>] mpage_prepare_extent_to_map+0x74f/0x970 fs/ext4/inode.c:2474
RSP: 0018:ffff8801d968f0a0  EFLAGS: 00010293
RAX: ffff8801d95d8000 RBX: ffffea00074304c0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff816d736f RDI: ffffea00074304c8
RBP: ffff8801d968f268 R08: ffff8801d95d8978 R09: 0000000000000001
R10: 0000000000000000 R11: ffff8801d95d8000 R12: 0000000000000001
R13: 0000000000000000 R14: ffff8801d968f3b0 R15: dffffc0000000000
FS:  00007fd866234700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd8661d0e78 CR3: 00000001cedba000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d968f1c8 1ffff1003b2d1e24 ffff8801d968f3b8 ffff8801d968f140
 ffff8801d968f3c0 00000002b64da2e8 ffff8801cc0fc3d8 000000090000000c
 7fffffffffffffff ffff8801d968f180 ffff8801d968f3c8 ffffea00074304d0
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
 [<ffffffff81422689>] filemap_write_and_wait_range+0x59/0xb0 mm/filemap.c:535
 [<ffffffff81423961>] generic_file_direct_write+0x131/0x4e0 mm/filemap.c:2425
 [<ffffffff81423f64>] __generic_file_write_iter+0x254/0x550 mm/filemap.c:2630
 [<ffffffff816c4ae1>] ext4_file_write_iter+0x601/0xc60 fs/ext4/file.c:171
 [<ffffffff8151be6c>] vfs_iter_write+0x1cc/0x2d0 fs/read_write.c:364
 [<ffffffff815b7e62>] iter_file_splice_write+0x622/0xb90 fs/splice.c:1024
 [<ffffffff815b49b8>] do_splice_from fs/splice.c:1128 [inline]
 [<ffffffff815b49b8>] direct_splice_actor+0x128/0x190 fs/splice.c:1294
 [<ffffffff815b5a67>] splice_direct_to_actor+0x2c7/0x830 fs/splice.c:1247
 [<ffffffff815b6173>] do_splice_direct+0x1a3/0x270 fs/splice.c:1337
 [<ffffffff8151ff14>] do_sendfile+0x4e4/0xb80 fs/read_write.c:1227
 [<ffffffff81521f03>] SYSC_sendfile64 fs/read_write.c:1282 [inline]
 [<ffffffff81521f03>] SyS_sendfile64+0xc3/0x150 fs/read_write.c:1274
 [<ffffffff838c0225>] entry_SYSCALL_64_fastpath+0x22/0x9e
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 <ffff8801d968f0a0>
---[ end trace 4e161cc58efb0e6e ]---