=======================================================
ocfs2: Slot 0 on device (7,0) was already allocated to this node!
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
------------[ cut here ]------------
kernel BUG at fs/ocfs2/suballoc.c:1443!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5460 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_find_victim_chain fs/ocfs2/suballoc.c:1443 [inline]
RIP: 0010:ocfs2_claim_suballoc_bits+0x243c/0x2450 fs/ocfs2/suballoc.c:1996
Code: c2 fb ff ff e8 65 ce 11 fe 90 0f 0b e8 5d ce 11 fe 90 0f 0b e8 55 ce 11 fe 90 0f 0b e8 4d ce 11 fe 90 0f 0b e8 45 ce 11 fe 90 <0f> 0b e8 3d ce 11 fe 90 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90
RSP: 0018:ffffc900028b72a0 EFLAGS: 00010293
RAX: ffffffff83ae854b RBX: 0000000000000000 RCX: ffff888000f8a480
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900028b7530 R08: ffffc900028b75c0 R09: 0000000000000000
R10: ffffc900028b75c0 R11: fffff52000516ebd R12: ffff888011ed7308
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff110023dae61
FS:  00005555716a6500(0000) GS:ffff88808d300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002040 CR3: 00000000595ce000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 ocfs2_claim_new_inode+0x332/0x7a0 fs/ocfs2/suballoc.c:2292
 ocfs2_mknod_locked+0x100/0x250 fs/ocfs2/namei.c:637
 ocfs2_mknod+0x10c7/0x2050 fs/ocfs2/namei.c:384
 ocfs2_mkdir+0x191/0x440 fs/ocfs2/namei.c:659
 vfs_mkdir+0x306/0x510 fs/namei.c:4453
 do_mkdirat+0x247/0x590 fs/namei.c:4486
 __do_sys_mkdirat fs/namei.c:4503 [inline]
 __se_sys_mkdirat fs/namei.c:4501 [inline]
 __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f888338efc9
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:00007ffea8406988 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f88835e5fa0 RCX: 00007f888338efc9
RDX: 0000000000000000 RSI: 0000200000002040 RDI: ffffffffffffff9c
RBP: 00007f8883411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f88835e5fa0 R14: 00007f88835e5fa0 R15: 0000000000000003
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ocfs2_find_victim_chain fs/ocfs2/suballoc.c:1443 [inline]
RIP: 0010:ocfs2_claim_suballoc_bits+0x243c/0x2450 fs/ocfs2/suballoc.c:1996
Code: c2 fb ff ff e8 65 ce 11 fe 90 0f 0b e8 5d ce 11 fe 90 0f 0b e8 55 ce 11 fe 90 0f 0b e8 4d ce 11 fe 90 0f 0b e8 45 ce 11 fe 90 <0f> 0b e8 3d ce 11 fe 90 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90
RSP: 0018:ffffc900028b72a0 EFLAGS: 00010293
RAX: ffffffff83ae854b RBX: 0000000000000000 RCX: ffff888000f8a480
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900028b7530 R08: ffffc900028b75c0 R09: 0000000000000000
R10: ffffc900028b75c0 R11: fffff52000516ebd R12: ffff888011ed7308
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff110023dae61
FS:  00005555716a6500(0000) GS:ffff88808d300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002040 CR3: 00000000595ce000 CR4: 0000000000352ef0