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 <efcb591e162ff0b04a9878f7250ab6ee6907f4a4.camel@mediatek.com>
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From: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Date: Fri, 12 Jan 2024 12:31:07 +0500
Message-ID: <CABXGCsPF6MbSOpfUBbT77Hnfc450kutsc8Fzr1O_O9bgtQ5PAw@mail.gmail.com>
Subject: Re: [BUG] Unloading mt7921e module cause use-after-free
To: =?UTF-8?B?RGVyZW4gV3UgKOatpuW+t+S7gSk=?= <Deren.Wu@mediatek.com>
Cc: "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>, "nbd@nbd.name" <nbd@nbd.name>, 
	"angelogioacchino.delregno@collabora.com" <angelogioacchino.delregno@collabora.com>, 
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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On Fri, Jan 12, 2024 at 10:34=E2=80=AFAM Deren Wu (=E6=AD=A6=E5=BE=B7=E4=BB=
=81) <Deren.Wu@mediatek.com> wrote:
>
> Hi Mikhail,
>
> I can reproduce a similar problem when CONFI_DEBUG_SHIRQ is enabled.
>
> Pleaese try this patch in mainline kernel (6.7+)
> ---
> --- a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> @@ -387,6 +387,7 @@ static void mt7921_pci_remove(struct pci_dev *pdev)
>         struct mt792x_dev *dev =3D container_of(mdev, struct mt792x_dev,
> mt76);
>
>         mt7921e_unregister_device(dev);
> +       set_bit(MT76_REMOVED, &mdev->phy.state);
>         devm_free_irq(&pdev->dev, pdev->irq, dev);
>         mt76_free_device(&dev->mt76);
>         pci_free_irq_vectors(pdev);
> diff --git a/drivers/net/wireless/mediatek/mt76/mt792x_dma.c
> b/drivers/net/wireless/mediatek/mt76/mt792x_dma.c
> index 488326ce5ed4..3893dbe866fe 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt792x_dma.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt792x_dma.c
> @@ -12,6 +12,8 @@ irqreturn_t mt792x_irq_handler(int irq, void
> *dev_instance)
>  {
>         struct mt792x_dev *dev =3D dev_instance;
>
> +       if (test_bit(MT76_REMOVED, &dev->mt76.phy.state))
> +               return IRQ_NONE;
>         mt76_wr(dev, dev->irq_map->host_irq_enable, 0);
>
>         if (!test_bit(MT76_STATE_INITIALIZED, &dev->mphy.state))
>
>

Thanks, this patch looks good to me.
Demonstration: https://youtu.be/nKnA2ftVoXw

Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>

--=20
Best Regards,
Mike Gavrilov.