From 8ba438ef3cacc4808a63ed0ce24d4f0942cfe55d Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Sun, 23 Jul 2023 22:24:59 +0200 Subject: [PATCH] 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. Fixes: 8ca151b568b6 ("iwlwifi: add the MVM driver") Signed-off-by: Christophe JAILLET Acked-by: Gregory Greenman Link: https://lore.kernel.org/r/23f0ec986ef1529055f4f93dcb3940a6cf8d9a94.1690143750.git.christophe.jaillet@wanadoo.fr Signed-off-by: Johannes Berg --- drivers/net/wireless/intel/iwlwifi/mvm/fw.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c index 1f5db65..1d5ee43 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c @@ -802,7 +802,7 @@ out: mvm->nvm_data->bands[0].n_channels = 1; mvm->nvm_data->bands[0].n_bitrates = 1; mvm->nvm_data->bands[0].bitrates = - (void *)((u8 *)mvm->nvm_data->channels + 1); + (void *)(mvm->nvm_data->channels + 1); mvm->nvm_data->bands[0].bitrates->hw_value = 10; } -- 2.7.4