------------[ cut here ]------------
WARNING: CPU: 1 PID: 6448 at fs/bcachefs/fs-io.c:359 __bch2_truncate_folio+0x173a/0x19d0 fs/bcachefs/fs-io.c:359
Modules linked in:
CPU: 1 UID: 0 PID: 6448 Comm: syz.2.61 Not tainted 6.15.0-rc7-syzkaller-00014-gd608703fcdd9 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:__bch2_truncate_folio+0x173a/0x19d0 fs/bcachefs/fs-io.c:359
Code: 5f 5d c3 cc cc cc cc cc e8 b3 25 8e fd 48 c7 c7 c8 ad 7b 8d e8 47 27 ea ff 89 05 81 40 66 15 e9 ab ea ff ff e8 97 25 8e fd 90 <0f> 0b 90 e9 88 f9 ff ff e8 09 ab 1d 07 e8 84 25 8e fd be 00 10 00
RSP: 0018:ffffc90003a5f9e0 EFLAGS: 00010293
RAX: ffffffff8431cb49 RBX: 0000000000000000 RCX: ffff88804d585a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003a5fbb0 R08: ffffea000179c707 R09: 1ffffd40002f38e0
R10: dffffc0000000000 R11: fffff940002f38e1 R12: 1ffff1100ba373d6
R13: dffffc0000000000 R14: ffff88805d1b9eb0 R15: 0000000000000000
FS:  00007f5e24c806c0(0000) GS:ffff8881261f6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f33ef2fa6b0 CR3: 0000000059940000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bch2_truncate_folios fs/bcachefs/fs-io.c:398 [inline]
 bchfs_fallocate+0x233/0x680 fs/bcachefs/fs-io.c:777
 bch2_fallocate_dispatch+0x345/0x4e0 fs/bcachefs/fs-io.c:836
 vfs_fallocate+0x6a0/0x830 fs/open.c:338
 ksys_fallocate fs/open.c:362 [inline]
 __do_sys_fallocate fs/open.c:367 [inline]
 __se_sys_fallocate fs/open.c:365 [inline]
 __x64_sys_fallocate+0xc0/0x110 fs/open.c:365
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5e23d8e969
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:00007f5e24c80038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f5e23fb5fa0 RCX: 00007f5e23d8e969
RDX: 0000000000000fff RSI: 0000000000000010 RDI: 0000000000000006
RBP: 00007f5e23e10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5e23fb5fa0 R15: 00007ffde6cf26f8
 </TASK>