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

Prevent null pointer dereference in mt7996_mmio_wed_init()

Fixes: 83eafc9251d6 ("wifi: mt76: mt7996: add wed tx support")
Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
---
V1 -> V2: Add a blank after the check and correct the summary.

 drivers/net/wireless/mediatek/mt76/mt7996/mmio.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c b/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
index 13b188e281bd..af9169030bad 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
@@ -323,6 +323,9 @@ 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

Hi all,

I’d like to kindly follow up on my previous patch submission to check if there
are any additional feedback or suggestions for improvement. If there are
further changes needed, I’ll be happy to address them and send a v3.

Please let me know if you have any comments. Thanks for your time and review!

Best regards,

Henry Martin <bsdhenrymartin@gmail.com> 于2025年4月7日周一 11:24写道：
>
> devm_ioremap() returns NULL on error. Currently, mt7996_mmio_wed_init()
> does not check for this case, which results in a NULL pointer
> dereference.
>
> Prevent null pointer dereference in mt7996_mmio_wed_init()
>
> Fixes: 83eafc9251d6 ("wifi: mt76: mt7996: add wed tx support")
> Signed-off-by: Henry Martin <bsdhenrymartin@gmail.com>
> ---
> V1 -> V2: Add a blank after the check and correct the summary.
>
>  drivers/net/wireless/mediatek/mt76/mt7996/mmio.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c b/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
> index 13b188e281bd..af9169030bad 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7996/mmio.c
> @@ -323,6 +323,9 @@ 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
>

…
> Prevent null pointer dereference in mt7996_mmio_wed_init()

Would you occasionally like to mark the end of sentences with a dot?


Can any other summary phrase variant become more desirable accordingly?

Regards,
Markus

On Mon, 2025-04-07 at 09:50 +0200, Markus Elfring wrote:
> …
> > Prevent null pointer dereference in mt7996_mmio_wed_init()
> 
> Would you occasionally like to mark the end of sentences with a dot?
> 

They did one out of two times. Go away from the wireless list.

johannes