------------[ cut here ]------------
WARNING: CPU: 0 PID: 9116 at fs/bcachefs/fs-io.c:361 __bch2_truncate_folio+0x10c9/0x12d0 fs/bcachefs/fs-io.c:361
Modules linked in:
CPU: 0 UID: 0 PID: 9116 Comm: syz.7.632 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__bch2_truncate_folio+0x10c9/0x12d0 fs/bcachefs/fs-io.c:361
Code: 89 df e8 8a 20 ad fd 90 0f 0b e8 92 65 65 fd 90 0f 0b e8 9a cf ca fd e9 10 f5 ff ff e8 80 65 65 fd 90 0f 0b e8 78 65 65 fd 90 <0f> 0b 90 e9 c5 f6 ff ff e8 6a 65 65 fd 90 0f 0b e8 42 cf ca fd e9
RSP: 0018:ffffc9000ae97bd0 EFLAGS: 00010283
RAX: 0000000000002657 RBX: ffff888058638798 RCX: ffffc9000bd3a000
RDX: 0000000000080000 RSI: ffffffff845628a8 RDI: 0000000000000006
RBP: ffffc9000ae97cd0 R08: 0000000000000006 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffea0001d3dcc0
R13: ffff88807c4d0700 R14: 0000000000000000 R15: ffff888046b80000
FS:  00007fd0b338b6c0(0000) GS:ffff8881246b7000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd0a827f000 CR3: 00000000347c7000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 bch2_truncate_folios+0x30/0xa0 fs/bcachefs/fs-io.c:400
 bchfs_fallocate+0x1df/0x570 fs/bcachefs/fs-io.c:777
 bch2_fallocate_dispatch+0x3a0/0x4b0 fs/bcachefs/fs-io.c:836
 vfs_fallocate+0x5b4/0x10e0 fs/open.c:342
 ksys_fallocate fs/open.c:366 [inline]
 __do_sys_fallocate fs/open.c:371 [inline]
 __se_sys_fallocate fs/open.c:369 [inline]
 __x64_sys_fallocate+0xd5/0x150 fs/open.c:369
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd0b258ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd0b338b038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007fd0b27c5fa0 RCX: 00007fd0b258ebe9
RDX: 0000000000000006 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00007fd0b2611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd0b27c6038 R14: 00007fd0b27c5fa0 R15: 00007fffaf510ce8
 </TASK>