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kernel BUG at fs/ext4/inode.c:2805!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 3852 Comm: kworker/u4:23 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:ext4_do_writepages+0x45b0/0x45c0 fs/ext4/inode.c:2804
Code: c6 00 12 7f 8b e8 70 13 ae fe 90 0f 0b e8 d8 19 47 ff 4c 89 f7 48 c7 c6 e0 15 7f 8b e8 59 13 ae fe 90 0f 0b e8 c1 19 47 ff 90 <0f> 0b 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90
RSP: 0018:ffffc9000e42ec00 EFLAGS: 00010293
RAX: ffffffff8279f46f RBX: 0000004210000000 RCX: ffff88803eec4980
RDX: 0000000000000000 RSI: 0000004000000000 RDI: 0000000000000000
RBP: ffffc9000e42f030 R08: ffff8880439e1377 R09: 1ffff1100873c26e
R10: dffffc0000000000 R11: ffffed100873c26f R12: 0000000000000001
R13: ffffc9000e42f080 R14: 0000004000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88808d6b7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1f99d98000 CR3: 00000000115e0000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 ext4_writepages+0x205/0x350 fs/ext4/inode.c:3021
 do_writepages+0x32e/0x550 mm/page-writeback.c:2598
 __writeback_single_inode+0x133/0x1240 fs/fs-writeback.c:1737
 writeback_sb_inodes+0x93a/0x1870 fs/fs-writeback.c:2030
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107
 wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218
 wb_check_start_all fs/fs-writeback.c:2344 [inline]
 wb_do_writeback fs/fs-writeback.c:2370 [inline]
 wb_workfn+0x8ee/0xed0 fs/fs-writeback.c:2403
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ext4_do_writepages+0x45b0/0x45c0 fs/ext4/inode.c:2804
Code: c6 00 12 7f 8b e8 70 13 ae fe 90 0f 0b e8 d8 19 47 ff 4c 89 f7 48 c7 c6 e0 15 7f 8b e8 59 13 ae fe 90 0f 0b e8 c1 19 47 ff 90 <0f> 0b 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90
RSP: 0018:ffffc9000e42ec00 EFLAGS: 00010293
RAX: ffffffff8279f46f RBX: 0000004210000000 RCX: ffff88803eec4980
RDX: 0000000000000000 RSI: 0000004000000000 RDI: 0000000000000000
RBP: ffffc9000e42f030 R08: ffff8880439e1377 R09: 1ffff1100873c26e
R10: dffffc0000000000 R11: ffffed100873c26f R12: 0000000000000001
R13: ffffc9000e42f080 R14: 0000004000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88808d6b7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1f99d98000 CR3: 0000000051337000 CR4: 0000000000352ef0