CVE-2023-52531

In the Linux kernel, the following vulnerability has been resolved:

wifi: iwlwifi: mvm: Fix a memory corruption issue

A few lines above, space is kzalloc()'ed for:
sizeof(struct iwl_nvm_data) +
sizeof(struct ieee80211_channel) +
sizeof(struct ieee80211_rate)

‘mvm->nvm_data’ is a ‘struct iwl_nvm_data’, so it is fine.

At the end of this structure, there is the ‘channels’ flex array.
Each element is of type ‘struct ieee80211_channel’.
So only 1 element is allocated in this array.

When doing:
mvm->nvm_data->bands[0].channels = mvm->nvm_data->channels;
We point at the first element of the ‘channels’ flex array.
So this is fine.

However, when doing:
mvm->nvm_data->bands[0].bitrates =
(void *)((u8 *)mvm->nvm_data->channels + 1);
because of the “(u8 *)” cast, we add only 1 to the address of the beginning
of the flex array.

It is likely that we want point at the ‘struct ieee80211_rate’ allocated
just after.

Remove the spurious casting so that the pointer arithmetic works as
expected.