[v5.15] WARNING in ext4_iomap_begin (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c79648372d02 Linux 5.15.189
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=128f19a2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f3b1215b3cf4119f
dashboard link: https://syzkaller.appspot.com/bug?extid=8ebd9f6d0fb9a8248a5f
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=161d8842580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1577b434580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/fa511d2a8893/disk-c7964837.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f14b6c77bbb9/vmlinux-c7964837.xz
kernel image: https://storage.googleapis.com/syzbot-assets/388987ba15c6/bzImage-c7964837.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/4b5cc0e851df/mount_4.gz
fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=179bc9a2580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8ebd9f...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 5187 at fs/ext4/inode.c:3436 ext4_iomap_begin+0xa0d/0xb80 fs/ext4/inode.c:3436
Modules linked in:

CPU: 1 PID: 5187 Comm: syz.4.184 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:ext4_iomap_begin+0xa0d/0xb80 fs/ext4/inode.c:3436
Code: 89 e8 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 87 fd 6f ff 48 bb 00 00 00 00 00 fc ff df e9 71 ff ff ff e8 73 fd 6f ff <0f> 0b 41 bd de ff ff ff 48 bb 00 00 00 00 00 fc ff df e9 7b ff ff
RSP: 0000:ffffc90004b3f600 EFLAGS: 00010293
RAX: ffffffff8207c6ad RBX: ffff88806eab8d62 RCX: ffff88801bae1dc0
RDX: 0000000000000000 RSI: 00000000000000d4 RDI: 0000000000000000
RBP: ffffc90004b3f780 R08: dffffc0000000000 R09: ffffed100dd5714a
R10: ffffed100dd5714a R11: 1ffff1100dd57149 R12: 00000000000000d4
R13: 1ffff1100dd571ac R14: 000000000000000b R15: 0000000000000000
FS: 00007f8233b546c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f476fe3cdac CR3: 000000005d3f3000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
iomap_iter+0x620/0xdb0 fs/iomap/iter.c:74
__iomap_dio_rw+0xa69/0x1a70 fs/iomap/direct-io.c:585
iomap_dio_rw+0x38/0x90 fs/iomap/direct-io.c:672
ext4_dio_write_iter fs/ext4/file.c:540 [inline]
ext4_file_write_iter+0x132b/0x17b0 fs/ext4/file.c:660
call_write_iter include/linux/fs.h:2172 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x712/0xd00 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+0x194/0x220 fs/read_write.c:708
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: 0033:0x7f82344e4be9
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:00007f8233b54038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f823470bfa0 RCX: 00007f82344e4be9
RDX: 0000000000000001 RSI: 0000200000000880 RDI: 0000000000000007
RBP: 00007f8234567e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000083 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f823470c038 R14: 00007f823470bfa0 R15: 00007ffcc18defb8
</TASK>


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