From 8ba438ef3cacc4808a63ed0ce24d4f0942cfe55d Mon Sep 17 00:00:00 2001
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Date: Sun, 23 Jul 2023 22:24:59 +0200
Subject: [PATCH] wifi: iwlwifi: mvm: Fix a memory corruption issue
Git-commit: 8ba438ef3cacc4808a63ed0ce24d4f0942cfe55d
Patch-mainline: v6.6-rc5
References: CVE-2023-52531 bsc#1220931
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 <christophe.jaillet@wanadoo.fr>
Acked-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/23f0ec986ef1529055f4f93dcb3940a6cf8d9a94.1690143750.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/net/wireless/intel/iwlwifi/mvm/fw.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
@@ -562,7 +562,7 @@ out:
mvm->nvm_data->bands[0].n_channels = 1;
mvm->nvm_data->bands[0].n_bitrates = 1;
mvm->nvm_data->bands[0].bitrates =
- (void *)mvm->nvm_data->channels + 1;
+ (void *)(mvm->nvm_data->channels + 1);
mvm->nvm_data->bands[0].bitrates->hw_value = 10;
}