------------[ cut here ]------------
kernel BUG at fs/ext4/mballoc.c:4765!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 13 Comm: kworker/u4:1 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_mb_use_inode_pa+0x6c1/0x720 fs/ext4/mballoc.c:4765
Code: e8 24 e7 a9 ff 48 ba 00 00 00 00 00 fc ff df e9 da fa ff ff e8 60 a8 42 ff 90 0f 0b e8 58 a8 42 ff 90 0f 0b e8 50 a8 42 ff 90 <0f> 0b e8 48 a8 42 ff 90 0f 0b 48 8b 0c 24 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc900001f6508 EFLAGS: 00010293
RAX: ffffffff827d6dd0 RBX: 00000000ffffffcd RCX: ffff88801ab40000
RDX: 0000000000000000 RSI: 0000000000000034 RDI: 0000000000000001
RBP: 1ffff110085170ef R08: ffff8880428b9333 R09: 1ffff11008517266
R10: dffffc0000000000 R11: ffffed1008517267 R12: 0000000000000000
R13: 0000000000000034 R14: 1ffff11008517269 R15: ffff8880428b9348
FS:  0000000000000000(0000) GS:ffff88808d732000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0c59951fc8 CR3: 0000000041e97000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 ext4_mb_use_preallocated+0x660/0x13f0 fs/ext4/mballoc.c:4982
 ext4_mb_new_blocks+0x5b4/0x4720 fs/ext4/mballoc.c:6286
 ext4_alloc_branch fs/ext4/indirect.c:340 [inline]
 ext4_ind_map_blocks+0xe42/0x21c0 fs/ext4/indirect.c:635
 ext4_map_create_blocks fs/ext4/inode.c:611 [inline]
 ext4_map_blocks+0x7fe/0x1740 fs/ext4/inode.c:811
 mpage_map_one_extent fs/ext4/inode.c:2374 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2468 [inline]
 ext4_do_writepages+0x16a1/0x4610 fs/ext4/inode.c:2931
 ext4_writepages+0x205/0x350 fs/ext4/inode.c:3025
 do_writepages+0x32e/0x550 mm/page-writeback.c:2604
 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719
 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:2015
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2086
 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2197
 wb_check_start_all fs/fs-writeback.c:2323 [inline]
 wb_do_writeback fs/fs-writeback.c:2349 [inline]
 wb_workfn+0x90b/0xef0 fs/fs-writeback.c:2382
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 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_mb_use_inode_pa+0x6c1/0x720 fs/ext4/mballoc.c:4765
Code: e8 24 e7 a9 ff 48 ba 00 00 00 00 00 fc ff df e9 da fa ff ff e8 60 a8 42 ff 90 0f 0b e8 58 a8 42 ff 90 0f 0b e8 50 a8 42 ff 90 <0f> 0b e8 48 a8 42 ff 90 0f 0b 48 8b 0c 24 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc900001f6508 EFLAGS: 00010293
RAX: ffffffff827d6dd0 RBX: 00000000ffffffcd RCX: ffff88801ab40000
RDX: 0000000000000000 RSI: 0000000000000034 RDI: 0000000000000001
RBP: 1ffff110085170ef R08: ffff8880428b9333 R09: 1ffff11008517266
R10: dffffc0000000000 R11: ffffed1008517267 R12: 0000000000000000
R13: 0000000000000034 R14: 1ffff11008517269 R15: ffff8880428b9348
FS:  0000000000000000(0000) GS:ffff88808d732000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0c59951fc8 CR3: 0000000041e97000 CR4: 0000000000352ef0