On Tue, 14 Feb 2023 at 14:24, Jason Wang jasowang@redhat.com wrote:

On Tue, Feb 14, 2023 at 2:17 PM Cindy Lu lulu@redhat.com 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).

sure, will post a new version Thanks Cindy

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[ 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@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Cindy Lu lulu@redhat.com

Other than above,

Acked-by: Jason Wang jasowang@redhat.com

Thanks

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---

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