[syzbot] [ntfs3?] WARNING in ntfs_extend_initialized_size (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 635c467cc14e Add linux-next specific files for 20260213
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=11d8c722580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f09eec269f9f4746
dashboard link: https://syzkaller.appspot.com/bug?extid=2bd8e813c7f767aa9bb1
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15996c02580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=138f115a580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/24870d51cbd0/disk-635c467c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/49283c738806/vmlinux-635c467c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8c5f9d1da977/bzImage-635c467c.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/0f8de5f7f0e7/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2bd8e8...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 4096
------------[ cut here ]------------
is_compressed(ni)
WARNING: fs/ntfs3/file.c:236 at ntfs_extend_initialized_size+0x1dc/0x210 fs/ntfs3/file.c:236, CPU#0: syz.0.17/5995
Modules linked in:
CPU: 0 UID: 0 PID: 5995 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:ntfs_extend_initialized_size+0x1dc/0x210 fs/ntfs3/file.c:236
Code: 0d ff 4c 89 33 31 ed eb 05 e8 20 6b a3 fe 89 e8 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d e9 cb a1 8e 08 cc e8 05 6b a3 fe 90 <0f> 0b 90 e9 31 ff ff ff 89 d1 80 e1 07 80 c1 03 38 c1 0f 8c e1 fe
RSP: 0018:ffffc90003667c30 EFLAGS: 00010293
RAX: ffffffff8322375b RBX: ffff88805c1f1670 RCX: ffff8880300f9e40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000800 R08: ffff88805c1f1737 R09: 1ffff1100b83e2e6
R10: dffffc0000000000 R11: ffffed100b83e2e7 R12: 0000000000000012
R13: 0000000000000fee R14: 1ffff1100b83e2ce R15: 0000000000000000
FS: 000055556ac47500(0000) GS:ffff888125460000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f963fff CR3: 000000007a426000 CR4: 00000000003526f0
Call Trace:
<TASK>
ntfs_fallocate+0xf21/0x1220 fs/ntfs3/file.c:670
vfs_fallocate+0x669/0x7e0 fs/open.c:340
ksys_fallocate fs/open.c:364 [inline]
__do_sys_fallocate fs/open.c:369 [inline]
__se_sys_fallocate fs/open.c:367 [inline]
__x64_sys_fallocate+0xc0/0x110 fs/open.c:367
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f248b59bf79
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:00007ffdfe289018 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f248b815fa0 RCX: 00007f248b59bf79
RDX: 0000000000000fff RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f248b6327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f248b815fac R14: 00007f248b815fa0 R15: 00007f248b815fa0
</TASK>


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