wifi: iwlwifi: mvm: Fix a memory corruption issue

Vulnerability Description

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.

References

• https://git.kernel.org/stable/c/7c8faa31080342aec4903c9acb20caf82fcca1ef
• https://git.kernel.org/stable/c/6b3223449c959a8be94a1f042288059e40fcccb0
• https://git.kernel.org/stable/c/f06cdd8d4ba5252986f51f80cc30263636397128
• https://git.kernel.org/stable/c/8ba438ef3cacc4808a63ed0ce24d4f0942cfe55d