CVE-2023-52531 Information

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.

Reference

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