[syzbot] [ocfs2?] kernel BUG in __ocfs2_move_extent

[syzbot <syzbot+727d161855d11d81e411@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    e406d57be7bd Merge tag 'mm-nonmm-stable-2025-10-02-15-29' ..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17739214580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=84e81c4d0c0e900a
dashboard link: https://syzkaller.appspot.com/bug?extid=727d161855d11d81e411
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15fc5334580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=156a9ee2580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-e406d57b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ed88be2e6138/vmlinux-e406d57b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/bdedb017e44c/bzImage-e406d57b.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/dc258190d4b3/mount_0.gz
  fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=17a54458580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+727d161855d11d81e411@syzkaller.appspotmail.com

         option from the mount to silence this warning.
=======================================================
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
------------[ cut here ]------------
kernel BUG at fs/ocfs2/move_extents.c:101!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5497 Comm: syz.0.17 Not tainted syzkaller #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:__ocfs2_move_extent+0xccf/0xce0 fs/ocfs2/move_extents.c:101
Code: ff 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c f0 fd ff ff 4c 89 e7 e8 01 d5 7b fe 48 8b 7c 24 08 e9 de fd ff ff e8 72 a9 14 fe 90 <0f> 0b 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffc9000cb4f320 EFLAGS: 00010293
RAX: ffffffff83a9e4ce RBX: 0000000000000000 RCX: ffff888000332480
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc9000cb4f488 R08: ffff888000332480 R09: 0000000000000006
R10: 00000000fffffffc R11: 0000000000000000 R12: 0000000000002550
R13: 0000000000000002 R14: dffffc0000000000 R15: 0000000000000000
FS:  000055556197a500(0000) GS:ffff88808d98a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000b000 CR3: 00000000591c9000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 ocfs2_move_extent fs/ocfs2/move_extents.c:672 [inline]
 __ocfs2_move_extents_range+0x2116/0x3380 fs/ocfs2/move_extents.c:859
 ocfs2_move_extents+0x378/0x960 fs/ocfs2/move_extents.c:926
 ocfs2_ioctl_move_extents+0x53e/0x710 fs/ocfs2/move_extents.c:1052
 ocfs2_ioctl+0x191/0x750 fs/ocfs2/ioctl.c:942
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:583
 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: 0033:0x7f57bad8eec9
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:00007ffd42f1aff8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f57bafe5fa0 RCX: 00007f57bad8eec9
RDX: 00002000000000c0 RSI: 0000000040406f06 RDI: 0000000000000004
RBP: 00007f57bae11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f57bafe5fa0 R14: 00007f57bafe5fa0 R15: 0000000000000003
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__ocfs2_move_extent+0xccf/0xce0 fs/ocfs2/move_extents.c:101
Code: ff 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c f0 fd ff ff 4c 89 e7 e8 01 d5 7b fe 48 8b 7c 24 08 e9 de fd ff ff e8 72 a9 14 fe 90 <0f> 0b 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffc9000cb4f320 EFLAGS: 00010293
RAX: ffffffff83a9e4ce RBX: 0000000000000000 RCX: ffff888000332480
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffc9000cb4f488 R08: ffff888000332480 R09: 0000000000000006
R10: 00000000fffffffc R11: 0000000000000000 R12: 0000000000002550
R13: 0000000000000002 R14: dffffc0000000000 R15: 0000000000000000
FS:  000055556197a500(0000) GS:ffff88808d98a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000b000 CR3: 00000000591c9000 CR4: 0000000000352ef0


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