wifi: ath: Silence memcpy run-time false positive warning

The memcpy() in ath_key_config() was attempting to write across
neighboring struct members in struct ath_keyval. Introduce a wrapping
struct_group, kv_values, to be the addressable target of the memcpy
without overflowing an individual member. Silences the false positive
run-time warning:

  memcpy: detected field-spanning write (size 32) of single field "hk.kv_val" at drivers/net/wireless/ath/key.c:506 (size 16)

Link: https://bbs.archlinux.org/viewtopic.php?id=282254
Cc: Kalle Valo <kvalo@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230210054310.never.554-kees@kernel.org

diff --git a/drivers/net/wireless/ath/ath.h b/drivers/net/wireless/ath/ath.h
index f083fb9..f02a308 100644 (file)
--- a/drivers/net/wireless/ath/ath.h
+++ b/drivers/net/wireless/ath/ath.h
@@ -96,11 +96,13 @@ struct ath_keyval {
        u8 kv_type;
        u8 kv_pad;
        u16 kv_len;
-       u8 kv_val[16]; /* TK */
-       u8 kv_mic[8]; /* Michael MIC key */
-       u8 kv_txmic[8]; /* Michael MIC TX key (used only if the hardware
-                        * supports both MIC keys in the same key cache entry;
-                        * in that case, kv_mic is the RX key) */
+       struct_group(kv_values,
+               u8 kv_val[16]; /* TK */
+               u8 kv_mic[8]; /* Michael MIC key */
+               u8 kv_txmic[8]; /* Michael MIC TX key (used only if the hardware
+                                * supports both MIC keys in the same key cache entry;
+                                * in that case, kv_mic is the RX key) */
+       );
 };
 
 enum ath_cipher {

diff --git a/drivers/net/wireless/ath/key.c b/drivers/net/wireless/ath/key.c
index 61b59a8..b7b61d4 100644 (file)
--- a/drivers/net/wireless/ath/key.c
+++ b/drivers/net/wireless/ath/key.c
@@ -503,7 +503,7 @@ int ath_key_config(struct ath_common *common,
 
        hk.kv_len = key->keylen;
        if (key->keylen)
-               memcpy(hk.kv_val, key->key, key->keylen);
+               memcpy(&hk.kv_values, key->key, key->keylen);
 
        if (!(key->flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
                switch (vif->type) {