[syzbot] [iomap?] [erofs?] WARNING in iomap_iter (5)

[syzbot <syzbot+d8f000c609f05f52d9b5@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    27605c8c0f69 Merge tag 'net-6.16-rc2' of git://git.kernel...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=171079d4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3a936e3316f9e2dc
dashboard link: https://syzkaller.appspot.com/bug?extid=d8f000c609f05f52d9b5
compiler:       Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1725310c580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=115e0e82580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-27605c8c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c55edb669703/vmlinux-27605c8c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e12830584492/bzImage-27605c8c.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/36391cabb242/mount_2.gz
  fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=165e0e82580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d8f000c609f05f52d9b5@syzkaller.appspotmail.com

erofs (device loop0): EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!
erofs (device loop0): mounted with root inode @ nid 36.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5317 at fs/iomap/iter.c:33 iomap_iter_done fs/iomap/iter.c:33 [inline]
WARNING: CPU: 0 PID: 5317 at fs/iomap/iter.c:33 iomap_iter+0x87c/0xdf0 fs/iomap/iter.c:113
Modules linked in:
CPU: 0 UID: 0 PID: 5317 Comm: syz-executor245 Not tainted 6.16.0-rc1-syzkaller-00101-g27605c8c0f69 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:iomap_iter_done fs/iomap/iter.c:33 [inline]
RIP: 0010:iomap_iter+0x87c/0xdf0 fs/iomap/iter.c:113
Code: cc cc cc e8 a6 eb 6b ff 90 0f 0b 90 e9 31 f8 ff ff e8 98 eb 6b ff 90 0f 0b 90 bd fb ff ff ff e9 ad fb ff ff e8 85 eb 6b ff 90 <0f> 0b 90 e9 22 fd ff ff e8 77 eb 6b ff 90 0f 0b 90 e9 53 fd ff ff
RSP: 0018:ffffc9000d08f808 EFLAGS: 00010293
RAX: ffffffff8254736b RBX: ffffc9000d08f920 RCX: ffff88803a692440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000074
RBP: 1ffff92001a11f2a R08: ffffea00010c5277 R09: 1ffffd4000218a4e
R10: dffffc0000000000 R11: fffff94000218a4f R12: 0000000000000074
R13: 0000000000000000 R14: ffffc9000d08f950 R15: 1ffff92001a11f25
FS:  0000555562dab380(0000) GS:ffff88808d252000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffeb97cc968 CR3: 0000000043323000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 iomap_fiemap+0x117/0x530 fs/iomap/fiemap.c:79
 ioctl_fiemap fs/ioctl.c:220 [inline]
 do_vfs_ioctl+0x16d3/0x1990 fs/ioctl.c:841
 __do_sys_ioctl fs/ioctl.c:905 [inline]
 __se_sys_ioctl+0x82/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbc6028fe59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffccc462b68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbc6028fe59
RDX: 0000200000000580 RSI: 00000000c020660b RDI: 0000000000000005
RBP: 00007fbc603045f0 R08: 0000555562dac4c0 R09: 0000555562dac4c0
R10: 00000000000001ca R11: 0000000000000246 R12: 00007ffccc462b90
R13: 00007ffccc462db8 R14: 431bde82d7b634db R15: 00007fbc602d903b
 </TASK>


---
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