[syzbot] [iommu?] WARNING in iommufd_device_unbind

[syzbot <syzbot+c92878e123785b1fa2db@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    c6d64479d609 Merge tag 'pull-statx' of git://git.kernel.or..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=129a0ae8580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b3b3b2f3eaae51f9
dashboard link: https://syzkaller.appspot.com/bug?extid=c92878e123785b1fa2db
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17da1bf7980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9d212f6bb1af/disk-c6d64479.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/21a14342211b/vmlinux-c6d64479.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f96c41f3e4a6/bzImage-c6d64479.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c92878e123785b1fa2db@syzkaller.appspotmail.com

iommufd: Time out waiting for iommufd object to become free
------------[ cut here ]------------
WARNING: CPU: 1 PID: 6050 at drivers/iommu/iommufd/iommufd_private.h:208 iommufd_object_destroy_user drivers/iommu/iommufd/iommufd_private.h:208 [inline]
WARNING: CPU: 1 PID: 6050 at drivers/iommu/iommufd/iommufd_private.h:208 iommufd_device_unbind+0x81/0xa0 drivers/iommu/iommufd/device.c:280
Modules linked in:
CPU: 1 UID: 0 PID: 6050 Comm: syz.3.18 Not tainted 6.12.0-syzkaller-00239-gc6d64479d609 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0010:iommufd_object_destroy_user drivers/iommu/iommufd/iommufd_private.h:208 [inline]
RIP: 0010:iommufd_device_unbind+0x81/0xa0 drivers/iommu/iommufd/device.c:280
Code: 00 e8 83 76 01 00 89 c3 31 ff 89 c6 e8 b8 85 43 fc 85 db 75 0f e8 6f 81 43 fc 5b 41 5e 41 5f c3 cc cc cc cc e8 60 81 43 fc 90 <0f> 0b 90 eb eb 89 f9 80 e1 07 80 c1 03 38 c1 7c b8 e8 d9 44 aa fc
RSP: 0018:ffffc90003017c38 EFLAGS: 00010293
RAX: ffffffff85516f50 RBX: 00000000fffffff0 RCX: ffff88802c693c00
RDX: 0000000000000000 RSI: 00000000fffffff0 RDI: 0000000000000000
RBP: ffffc90003017d70 R08: ffffffff85516f38 R09: 1ffff11005b9b140
R10: dffffc0000000000 R11: ffffed1005b9b141 R12: ffff888034149718
R13: ffff888034149700 R14: ffff888028d2c400 R15: dffffc0000000000
FS:  00007f2573c136c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c001633e80 CR3: 0000000032fda000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 iommufd_selftest_destroy+0x95/0xe0 drivers/iommu/iommufd/selftest.c:1439
 iommufd_object_remove+0x3b6/0x530 drivers/iommu/iommufd/main.c:211
 iommufd_fops_ioctl+0x4d6/0x5a0 drivers/iommu/iommufd/main.c:424
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2572d7e759
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:00007f2573c13038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f2572f36058 RCX: 00007f2572d7e759
RDX: 0000000020000400 RSI: 0000000000003b80 RDI: 0000000000000003
RBP: 00007f2572df175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f2572f36058 R15: 00007ffefd725ea8
 </TASK>


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