[PATCH 08/32] iwlwifi: mvm: Use mem_to_flex_dup() with struct ieee80211_key_conf

Kees Cook
2022-05-04T01:49:51Z

As part of the work to perform bounds checking on all memcpy() uses,
replace the open-coded a deserialization of bytes out of memory into a
trailing flexible array by using a flex_array.h helper to perform the
allocation, bounds checking, and copying.

Cc: Luca Coelho <luciano.coelho@intel.com>
Cc: Kalle Valo <kvalo@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Gregory Greenman <gregory.greenman@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
drivers/net/wireless/intel/iwlwifi/mvm/sta.c | 8 ++------
include/net/mac80211.h | 4 ++--
2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index 406f0a50a5bf..23cade528dcf 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -4108,7 +4108,7 @@ int iwl_mvm_add_pasn_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
int ret;
u16 queue;
struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
- struct ieee80211_key_conf *keyconf;
+ struct ieee80211_key_conf *keyconf = NULL;

ret = iwl_mvm_allocate_int_sta(mvm, sta, 0,
NL80211_IFTYPE_UNSPECIFIED,
@@ -4122,15 +4122,11 @@ int iwl_mvm_add_pasn_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
if (ret)
goto out;

- keyconf = kzalloc(sizeof(*keyconf) + key_len, GFP_KERNEL);
- if (!keyconf) {
+ if (mem_to_flex_dup(&keyconf, key, key_len, GFP_KERNEL)) {
ret = -ENOBUFS;
goto out;
}
-
keyconf->cipher = cipher;
- memcpy(keyconf->key, key, key_len);
- keyconf->keylen = key_len;

ret = iwl_mvm_send_sta_key(mvm, sta->sta_id, keyconf, false,
0, NULL, 0, 0, true);
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 75880fc70700..4abe52963a96 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1890,8 +1890,8 @@ struct ieee80211_key_conf {
u8 hw_key_idx;
s8 keyidx;
u16 flags;
- u8 keylen;
- u8 key[];
+ DECLARE_FLEX_ARRAY_ELEMENTS_COUNT(u8, keylen);
+ DECLARE_FLEX_ARRAY_ELEMENTS(u8, key);
};

#define IEEE80211_MAX_PN_LEN 16
--
2.32.0