vp_vdpa: fix the crash in hot unplug with vp_vdpa
CVE: CVE-2023-53082
Component: kernel
Severity: Low
CVSS v3: 5.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Release date: 2023-01-01T00:00:00+00:00

In the Linux kernel, the following vulnerability has been resolved:

vp_vdpa: fix the crash in hot unplug with vp_vdpa

While unplugging the vp_vdpa device, it triggers a kernel panic
The root cause is: vdpa_mgmtdev_unregister() will accesses modern
devices which will cause a use after free.
So need to change the sequence in vp_vdpa_remove

[  195.003359] BUG: unable to handle page fault for address: ff4e8beb80199014
[  195.004012] #PF: supervisor read access in kernel mode
[  195.004486] #PF: error_code(0x0000) - not-present page
[  195.004960] PGD 100000067 P4D 1001b6067 PUD 1001b7067 PMD 1001b8067 PTE 0
[  195.005578] Oops: 0000 1 PREEMPT SMP PTI
[  195.005968] CPU: 13 PID: 164 Comm: kworker/u56:10 Kdump: loaded Not tainted 5.14.0-252.el9.x86_64 #1
[  195.006792] Hardware name: Red Hat KVM/RHEL, BIOS edk2-20221207gitfff6d81270b5-2.el9 unknown
[  195.007556] Workqueue: kacpi_hotplug acpi_hotplug_work_fn
[  195.008059] RIP: 0010:ioread8+0x31/0x80
[  195.008418] Code: 77 28 48 81 ff 00 00 01 00 76 0b 89 fa ec 0f b6 c0 c3 cc cc cc cc 8b 15 ad 72 93 01 b8 ff 00 00 00 85 d2 75 0f c3 cc cc cc cc <8a> 07 0f b6 c0 c3 cc cc cc cc 83 ea 01 48 83 ec 08 48 89 fe 48 c7
[  195.010104] RSP: 0018:ff4e8beb8067bab8 EFLAGS: 00010292
[  195.010584] RAX: ffffffffc05834a0 RBX: ffffffffc05843c0 RCX: ff4e8beb8067bae0
[  195.011233] RDX: ff1bcbd580f88000 RSI: 0000000000000246 RDI: ff4e8beb80199014
[  195.011881] RBP: ff1bcbd587e39000 R08: ffffffff916fa2d0 R09: ff4e8beb8067ba68
[  195.012527] R10: 000000000000001c R11: 0000000000000000 R12: ff1bcbd5a3de9120
[  195.013179] R13: ffffffffc062d000 R14: 0000000000000080 R15: ff1bcbe402bc7805
[  195.013826] FS:  0000000000000000(0000) GS:ff1bcbe402740000(0000) knlGS:0000000000000000
[  195.014564] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  195.015093] CR2: ff4e8beb80199014 CR3: 0000000107dea002 CR4: 0000000000771ee0
[  195.015741] PKRU: 55555554
[  195.016001] Call Trace:
[  195.016233]  <TASK>
[  195.016434]  vp_modern_get_status+0x12/0x20
[  195.016823]  vp_vdpa_reset+0x1b/0x50 [vp_vdpa]
[  195.017238]  virtio_vdpa_reset+0x3c/0x48 [virtio_vdpa]
[  195.017709]  remove_vq_common+0x1f/0x3a0 [virtio_net]
[  195.018178]  virtnet_remove+0x5d/0x70 [virtio_net]
[  195.018618]  virtio_dev_remove+0x3d/0x90
[  195.018986]  device_release_driver_internal+0x1aa/0x230
[  195.019466]  bus_remove_device+0xd8/0x150
[  195.019841]  device_del+0x18b/0x3f0
[  195.020167]  ? kernfs_find_ns+0x35/0xd0
[  195.020526]  device_unregister+0x13/0x60
[  195.020894]  unregister_virtio_device+0x11/0x20
[  195.021311]  device_release_driver_internal+0x1aa/0x230
[  195.021790]  bus_remove_device+0xd8/0x150
[  195.022162]  device_del+0x18b/0x3f0
[  195.022487]  device_unregister+0x13/0x60
[  195.022852]  ? vdpa_dev_remove+0x30/0x30 [vdpa]
[  195.023270]  vp_vdpa_dev_del+0x12/0x20 [vp_vdpa]
[  195.023694]  vdpa_match_remove+0x2b/0x40 [vdpa]
[  195.024115]  bus_for_each_dev+0x78/0xc0
[  195.024471]  vdpa_mgmtdev_unregister+0x65/0x80 [vdpa]
[  195.024937]  vp_vdpa_remove+0x23/0x40 [vp_vdpa]
[  195.025353]  pci_device_remove+0x36/0xa0
[  195.025719]  device_release_driver_internal+0x1aa/0x230
[  195.026201]  pci_stop_bus_device+0x6c/0x90
[  195.026580]  pci_stop_and_remove_bus_device+0xe/0x20
[  195.027039]  disable_slot+0x49/0x90
[  195.027366]  acpiphp_disable_and_eject_slot+0x15/0x90
[  195.027832]  hotplug_event+0xea/0x210
[  195.028171]  ? hotplug_event+0x210/0x210
[  195.028535]  acpiphp_hotplug_notify+0x22/0x80
[  195.028942]  ? hotplug_event+0x210/0x210
[  195.029303]  acpi_device_hotplug+0x8a/0x1d0
[  195.029690]  acpi_hotplug_work_fn+0x1a/0x30
[  195.030077]  process_one_work+0x1e8/0x3c0
[  195.030451]  worker_thread+0x50/0x3b0
[  195.030791]  ? rescuer_thread+0x3a0/0x3a0
[  195.031165]  kthread+0xd9/0x100
[  195.031459]  ? kthread_complete_and_exit+0x20/0x20
[  195.031899]  ret_from_fork+0x22/0x30
[  195.032233]  </TASK>

Statement: A missing call order fix in vp_vdpa_remove() could lead to a use-after-free and kernel panic during hot-unplug of a VP VDPA device. This is due to accessing freed memory after unregistering the management device. Triggering this requires privileged access (e.g., root), typically during virtual device lifecycle operations such as device removal in KVM environments.

Remediation: