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kernel BUG at fs/ext4/inode.c:2826!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 68 Comm: kworker/u4:4 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:ext4_do_writepages+0x465f/0x4670 fs/ext4/inode.c:2825
Code: c6 e0 62 e4 8b e8 01 65 9f fe 90 0f 0b e8 19 11 3d ff 4c 89 f7 48 c7 c6 c0 67 e4 8b e8 ea 64 9f fe 90 0f 0b e8 02 11 3d ff 90 <0f> 0b 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffc90000acec80 EFLAGS: 00010293
RAX: ffffffff8288a99e RBX: 0000004210000000 RCX: ffff8880008bca00
RDX: 0000000000000000 RSI: 0000004000000000 RDI: 0000000000000000
RBP: ffffc90000acf090 R08: ffff888047208057 R09: 1ffff11008e4100a
R10: dffffc0000000000 R11: ffffed1008e4100b R12: dffffc0000000000
R13: 0000000000000001 R14: 0000004000000000 R15: 1ffff110024174c5
FS:  0000000000000000(0000) GS:ffff88808c888000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e1bfe70b0 CR3: 00000000124ba000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3042
 do_writepages+0x32e/0x550 mm/page-writeback.c:2575
 __writeback_single_inode+0x133/0x10e0 fs/fs-writeback.c:1764
 writeback_sb_inodes+0x979/0x19d0 fs/fs-writeback.c:2056
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2132
 wb_writeback+0x459/0xb00 fs/fs-writeback.c:2243
 wb_check_start_all fs/fs-writeback.c:2369 [inline]
 wb_do_writeback fs/fs-writeback.c:2395 [inline]
 wb_workfn+0x921/0xf10 fs/fs-writeback.c:2428
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_do_writepages+0x465f/0x4670 fs/ext4/inode.c:2825