Re: [PATCH] wifi: brcmfmac: pcie: handle randbuf allocation failure

From: Kalle Valo
Date: Wed Mar 06 2024 - 05:57:15 EST


Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx> writes:

> On 3/1/2024 2:51 PM, Duoming Zhou wrote:
>> The kzalloc() in brcmf_pcie_download_fw_nvram() will return
>> null if the physical memory has run out. As a result, if we
>> use get_random_bytes() to generate random bytes in the randbuf,
>> the null pointer dereference bug will happen.
>> Return -ENOMEM from brcmf_pcie_download_fw_nvram() if kzalloc()
>> fails for randbuf.
>> Fixes: 91918ce88d9f ("wifi: brcmfmac: pcie: Provide a buffer of
>> random bytes to the device")
>
> Looks good to me. Looking for kernel guideline about stack usage to
> determine whether it would be ok to just use buffer on stack. Does
> anyone know. This one is 256 bytes so I guess the allocation is
> warranted here.

Arnd, what do you suggest? Do we have any documentation or guidelines
anywhere?

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