On Tue, Feb 14, 2023 at 2:17 PM Cindy Lu <lulu@xxxxxxxxxx> wrote:
>
> While unplugging the vp_vdpa device, the kernel will crash
> The root cause is the function vp_modern_get_status() called following the
> vp_modern_remove().
This needs some tweaking, maybe it's better to say
vdpa_mgmtdev_unregister() will access modern devices which will cause
a use after free.
>So need to change the sequence in vp_vdpa_remove
>
> [ 195.016001] Call Trace:
Let's paste the full log with the reason for the calltrace (e.g
general protection fault or whatever else).
> [ 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>
>
> Fixes: ffbda8e9df10 ("vdpa/vp_vdpa : add vdpa tool support in vp_vdpa")
> Tested-by: Lei Yang <leiyang@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Cindy Lu <lulu@xxxxxxxxxx>
Other than above,
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
Thanks
> ---
> drivers/vdpa/virtio_pci/vp_vdpa.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vdpa/virtio_pci/vp_vdpa.c b/drivers/vdpa/virtio_pci/vp_vdpa.c
> index 8fe267ca3e76..281287fae89f 100644
> --- a/drivers/vdpa/virtio_pci/vp_vdpa.c
> +++ b/drivers/vdpa/virtio_pci/vp_vdpa.c
> @@ -645,8 +645,8 @@ static void vp_vdpa_remove(struct pci_dev *pdev)
> struct virtio_pci_modern_device *mdev = NULL;
>
> mdev = vp_vdpa_mgtdev->mdev;
> - vp_modern_remove(mdev);
> vdpa_mgmtdev_unregister(&vp_vdpa_mgtdev->mgtdev);
> + vp_modern_remove(mdev);
> kfree(vp_vdpa_mgtdev->mgtdev.id_table);
> kfree(mdev);
> kfree(vp_vdpa_mgtdev);
> --
> 2.34.3
>
