EXT4-fs (loop4): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 28
EXT4-fs (loop4): This should not happen!! Data will be lost
EXT4-fs (loop4): Total free blocks count 0
EXT4-fs (loop4): Free/Dirty block details
EXT4-fs (loop4): free_blocks=4096
EXT4-fs (loop4): dirty_blocks=16
EXT4-fs (loop4): Block reservation details
EXT4-fs (loop4): i_reserved_data_blocks=1
------------[ cut here ]------------
kernel BUG at fs/ext4/inode.c:2747!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4618 Comm: syz.4.1184 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:ext4_writepages+0x3069/0x3090 fs/ext4/inode.c:2746
Code: 00 00 00 e8 79 2a 8e ff 84 db 75 2c e8 e0 27 8e ff 49 bc 00 00 00 00 00 fc ff df 48 8b 5c 24 20 e9 8e f7 ff ff e8 c7 27 8e ff <0f> 0b e8 c0 27 8e ff e8 e7 d9 24 ff eb a2 e8 b4 27 8e ff e8 db d9
RSP: 0018:ffffc90000b97360 EFLAGS: 00010293
RAX: ffffffff81db9f19 RBX: 0000008410000000 RCX: ffff8881071be2c0
RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000
RBP: ffffc90000b976d0 R08: ffff888129947537 R09: 1ffff11025328ea6
R10: dffffc0000000000 R11: ffffed1025328ea7 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000008000000000 R15: ffff8881299477c8
FS:  00007faa6a72b6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000400 CR3: 0000000118f93000 CR4: 00000000003506b0
Call Trace:
 <TASK>
 do_writepages+0x473/0x6c0 mm/page-writeback.c:2388
 filemap_fdatawrite_wbc+0x1f4/0x250 mm/filemap.c:409
 __filemap_fdatawrite_range mm/filemap.c:442 [inline]
 file_write_and_wait_range+0x14d/0x220 mm/filemap.c:819
 ext4_sync_file+0x1a9/0xa10 fs/ext4/fsync.c:151
 vfs_fsync_range+0x190/0x1a0 fs/sync.c:188
 generic_write_sync include/linux/fs.h:3038 [inline]
 ext4_buffered_write_iter+0x5d0/0x670 fs/ext4/file.c:277
 ext4_file_write_iter+0x440/0x1540 fs/ext4/file.c:-1
 call_write_iter include/linux/fs.h:2212 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x835/0xfd0 fs/read_write.c:594
 ksys_pwrite64 fs/read_write.c:701 [inline]
 __do_sys_pwrite64 fs/read_write.c:711 [inline]
 __se_sys_pwrite64 fs/read_write.c:708 [inline]
 __x64_sys_pwrite64+0x197/0x220 fs/read_write.c:708
 x64_sys_call+0xa6/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:19
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7faa6bcd0819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007faa6a72b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007faa6bf49fa0 RCX: 00007faa6bcd0819
RDX: 0000000000000001 RSI: 0000200000000140 RDI: 00000000000000cf
RBP: 00007faa6bd66c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007faa6bf4a038 R14: 00007faa6bf49fa0 R15: 00007ffd8d8f8718
 </TASK>
Modules linked in:
---[ end trace 23b9fc60d38e4ab2 ]---
RIP: 0010:ext4_writepages+0x3069/0x3090 fs/ext4/inode.c:2746
Code: 00 00 00 e8 79 2a 8e ff 84 db 75 2c e8 e0 27 8e ff 49 bc 00 00 00 00 00 fc ff df 48 8b 5c 24 20 e9 8e f7 ff ff e8 c7 27 8e ff <0f> 0b e8 c0 27 8e ff e8 e7 d9 24 ff eb a2 e8 b4 27 8e ff e8 db d9
RSP: 0018:ffffc90000b97360 EFLAGS: 00010293
RAX: ffffffff81db9f19 RBX: 0000008410000000 RCX: ffff8881071be2c0
RDX: 0000000000000000 RSI: 0000008000000000 RDI: 0000000000000000
RBP: ffffc90000b976d0 R08: ffff888129947537 R09: 1ffff11025328ea6
R10: dffffc0000000000 R11: ffffed1025328ea7 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000008000000000 R15: ffff8881299477c8
FS:  00007faa6a72b6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdaba11fe20 CR3: 0000000118f93000 CR4: 00000000003506a0