devm_ioremap() returns NULL on error. Currently, mt7996_mmio_wed_init()
does not check for this case, which results in a NULL pointer
dereference.

Add NULL check after devm_ioremap() to prevent this issue.

Fixes: 83eafc9251d6 ("wifi: mt76: mt7996: add wed tx support")
Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
---
 drivers/net/wireless/mediatek/mt76/mt7996/mmio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c b/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
index 13b188e281bd..5bade83238bd 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
@@ -323,6 +323,8 @@ int mt7996_mmio_wed_init(struct mt7996_dev *dev, void *pdev_ptr,
 	wed->wlan.base = devm_ioremap(dev->mt76.dev,
 				      pci_resource_start(pci_dev, 0),
 				      pci_resource_len(pci_dev, 0));
+	if (!wed->wlan.base)
+		return -ENOMEM;
 	wed->wlan.phy_base = pci_resource_start(pci_dev, 0);
 
 	if (hif2) {
-- 
2.34.1

…
> Add NULL check after devm_ioremap() to prevent this issue.

Can a summary phrase like “Prevent null pointer dereference in mt7996_mmio_wed_init()”
be a bit nicer?


…
> +++ b/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
> @@ -323,6 +323,8 @@ int mt7996_mmio_wed_init(struct mt7996_dev *dev, void *pdev_ptr,
>  	wed->wlan.base = devm_ioremap(dev->mt76.dev,
>  				      pci_resource_start(pci_dev, 0),
>  				      pci_resource_len(pci_dev, 0));
> +	if (!wed->wlan.base)
> +		return -ENOMEM;

Can a blank line be desirable after such a statement?

Regards,
Markus

Ok, I will correct them in V2.

Regards,
Henry

Markus Elfring <Markus.Elfring@web.de> 于2025年4月3日周四 18:13写道：
>
> …
> > Add NULL check after devm_ioremap() to prevent this issue.
>
> Can a summary phrase like “Prevent null pointer dereference in mt7996_mmio_wed_init()”
> be a bit nicer?
>
>
> …
> > +++ b/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
> > @@ -323,6 +323,8 @@ int mt7996_mmio_wed_init(struct mt7996_dev *dev, void *pdev_ptr,
> >       wed->wlan.base = devm_ioremap(dev->mt76.dev,
> >                                     pci_resource_start(pci_dev, 0),
> >                                     pci_resource_len(pci_dev, 0));
> > +     if (!wed->wlan.base)
> > +             return -ENOMEM;
>
> Can a blank line be desirable after such a statement?
>
> Regards,
> Markus