[v6.1] WARNING in ext4_iomap_begin (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 8ce36b2849ef Linux 6.1.163
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12d54652580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0605c5af04d7603
dashboard link: https://syzkaller.appspot.com/bug?extid=2a3e2306a172391c8860
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/25d3bb1313db/disk-8ce36b28.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/53d3c77e16da/vmlinux-8ce36b28.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ca171a78e481/bzImage-8ce36b28.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2a3e23...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 7583 at fs/ext4/inode.c:3466 ext4_iomap_begin+0x9c1/0xb10 fs/ext4/inode.c:3466
Modules linked in:
CPU: 0 PID: 7583 Comm: syz.6.722 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:ext4_iomap_begin+0x9c1/0xb10 fs/ext4/inode.c:3466
Code: 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 26 1d 5d ff 4c 8b 64 24 28 48 8d 9c 24 d0 00 00 00 e9 6b ff ff ff e8 0f 1d 5d ff <0f> 0b 41 be de ff ff ff e9 56 f7 ff ff 89 d9 80 e1 07 38 c1 0f 8c
RSP: 0018:ffffc90003857620 EFLAGS: 00010287
RAX: ffffffff822556a1 RBX: ffff888068785dc2 RCX: 0000000000080000
RDX: ffffc9000f653000 RSI: 0000000000007541 RDI: 0000000000007542
RBP: ffffc90003857790 R08: ffff888068785a9f R09: 1ffff1100d0f0b53
R10: dffffc0000000000 R11: ffffed100d0f0b54 R12: 00000000000000d4
R13: 1ffff1100d0f0bb8 R14: 000000000000000b R15: 0000000000000000
FS: 00007f81abc776c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe48fdf020 CR3: 000000005bae1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
iomap_iter+0x6c6/0x1040 fs/iomap/iter.c:91
__iomap_dio_rw+0xd52/0x1e30 fs/iomap/direct-io.c:593
iomap_dio_rw+0x41/0xa0 fs/iomap/direct-io.c:682
ext4_dio_write_iter fs/ext4/file.c:554 [inline]
ext4_file_write_iter+0x12b7/0x1710 fs/ext4/file.c:674
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x4b1/0xa30 fs/read_write.c:584
ksys_write+0x14c/0x250 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f81aad9bf79
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:00007f81abc77028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f81ab016090 RCX: 00007f81aad9bf79
RDX: 0000000000032600 RSI: 0000200000000140 RDI: 0000000000000004
RBP: 00007f81aae327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f81ab016128 R14: 00007f81ab016090 R15: 00007ffde27af0b8
</TASK>


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