mwifiex: avoid -Wstringop-overflow warning

gcc-10 reports a warning for mwifiex_cmd_802_11_key_material_v1:

drivers/net/wireless/marvell/mwifiex/sta_cmd.c: In function 'mwifiex_cmd_802_11_key_material_v1':
cc1: warning: writing 16 bytes into a region of size 0 [-Wstringop-overflow=]
In file included from drivers/net/wireless/marvell/mwifiex/sta_cmd.c:23:
drivers/net/wireless/marvell/mwifiex/fw.h:993:9: note: at offset 0 to object 'action' with size 2 declared here
  993 |  __le16 action;
      |         ^~~~~~

As the warning makes no sense, I reported it as a bug for gcc. In the
meantime using a temporary pointer for the key data makes the code easier
to read and stops the warning.

Fixes: 5e6e3a92b9a4 ("wireless: mwifiex: initial commit for Marvell mwifiex driver")
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94881
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200430213101.135134-4-arnd@arndb.de

diff --git a/drivers/net/wireless/marvell/mwifiex/sta_cmd.c b/drivers/net/wireless/marvell/mwifiex/sta_cmd.c
index 0bd93f2..8bd355d 100644 (file)
--- a/drivers/net/wireless/marvell/mwifiex/sta_cmd.c
+++ b/drivers/net/wireless/marvell/mwifiex/sta_cmd.c
@@ -853,43 +853,36 @@ mwifiex_cmd_802_11_key_material_v1(struct mwifiex_private *priv,
                memset(&key_material->key_param_set, 0,
                       sizeof(struct mwifiex_ie_type_key_param_set));
        if (enc_key->is_wapi_key) {
+               struct mwifiex_ie_type_key_param_set *set;
+
                mwifiex_dbg(priv->adapter, INFO, "info: Set WAPI Key\n");
-               key_material->key_param_set.key_type_id =
-                                               cpu_to_le16(KEY_TYPE_ID_WAPI);
+               set = &key_material->key_param_set;
+               set->key_type_id = cpu_to_le16(KEY_TYPE_ID_WAPI);
                if (cmd_oid == KEY_INFO_ENABLED)
-                       key_material->key_param_set.key_info =
-                                               cpu_to_le16(KEY_ENABLED);
+                       set->key_info = cpu_to_le16(KEY_ENABLED);
                else
-                       key_material->key_param_set.key_info =
-                                               cpu_to_le16(!KEY_ENABLED);
+                       set->key_info = cpu_to_le16(!KEY_ENABLED);
 
-               key_material->key_param_set.key[0] = enc_key->key_index;
+               set->key[0] = enc_key->key_index;
                if (!priv->sec_info.wapi_key_on)
-                       key_material->key_param_set.key[1] = 1;
+                       set->key[1] = 1;
                else
                        /* set 0 when re-key */
-                       key_material->key_param_set.key[1] = 0;
+                       set->key[1] = 0;
 
                if (!is_broadcast_ether_addr(enc_key->mac_addr)) {
                        /* WAPI pairwise key: unicast */
-                       key_material->key_param_set.key_info |=
-                               cpu_to_le16(KEY_UNICAST);
+                       set->key_info |= cpu_to_le16(KEY_UNICAST);
                } else {        /* WAPI group key: multicast */
-                       key_material->key_param_set.key_info |=
-                               cpu_to_le16(KEY_MCAST);
+                       set->key_info |= cpu_to_le16(KEY_MCAST);
                        priv->sec_info.wapi_key_on = true;
                }
 
-               key_material->key_param_set.type =
-                                       cpu_to_le16(TLV_TYPE_KEY_MATERIAL);
-               key_material->key_param_set.key_len =
-                                               cpu_to_le16(WAPI_KEY_LEN);
-               memcpy(&key_material->key_param_set.key[2],
-                      enc_key->key_material, enc_key->key_len);
-               memcpy(&key_material->key_param_set.key[2 + enc_key->key_len],
-                      enc_key->pn, PN_LEN);
-               key_material->key_param_set.length =
-                       cpu_to_le16(WAPI_KEY_LEN + KEYPARAMSET_FIXED_LEN);
+               set->type = cpu_to_le16(TLV_TYPE_KEY_MATERIAL);
+               set->key_len = cpu_to_le16(WAPI_KEY_LEN);
+               memcpy(&set->key[2], enc_key->key_material, enc_key->key_len);
+               memcpy(&set->key[2 + enc_key->key_len], enc_key->pn, PN_LEN);
+               set->length = cpu_to_le16(WAPI_KEY_LEN + KEYPARAMSET_FIXED_LEN);
 
                key_param_len = (WAPI_KEY_LEN + KEYPARAMSET_FIXED_LEN) +
                                 sizeof(struct mwifiex_ie_types_header);