Re: [PATCH v1] wifi: brcmfmac: acpi: Add NULL check in brcmf_acpi_probe()

[Arend Van Spriel]

On April 1, 2025 4:09:36 PM Henry Martin <bsdhenrymartin@xxxxxxxxx> wrote:

> devm_kasprintf() returns NULL when memory allocation fails. Currently,
> brcmf_acpi_probe() does not check for this case, which results in a NULL
> pointer dereference.
>
> Add NULL check after devm_kasprintf() to prevent this issue.
>
> Fixes: 0f485805d008 ("wifi: brcmfmac: acpi: Add support for fetching Apple 
> ACPI properties")
> Signed-off-by: Henry Martin <bsdhenrymartin@xxxxxxxxx>
> ---
> drivers/net/wireless/broadcom/brcm80211/brcmfmac/acpi.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/acpi.c 
> b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/acpi.c
> index c4a54861bfb4..4885d5d0a0af 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/acpi.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/acpi.c
> @@ -25,6 +25,8 @@ void brcmf_acpi_probe(struct device *dev, enum 
> brcmf_bus_type bus_type,
>  settings->board_type = devm_kasprintf(dev, GFP_KERNEL,
>       "apple,%s",
>       o->string.pointer);
> + if (!settings->board_type)
> + return -ENOMEM;

brcmf_acpi_probe() has void return type so this would give a compiler 
warning. I expect submitted patches at least do pass compilation.

After digging through the driver code I see a null check everywhere it is 
used. Can you please provide a kernel log with a null deref so I may have a 
clue where it goes wrong? If any.

Regards,
Arend
>