Re: [PATCH v2] vp_vdpa: fix the crash in hot unplug with vp_vdpa

[Jason Wang]

On Tue, Feb 14, 2023 at 4:09 PM Cindy Lu <lulu@xxxxxxxxxx> wrote:
>
> 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>
>
> 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>

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
>