Subject: [PATCH 5.10 044/211] wifi: ath: Silence memcpy run-time false positive warning

From: Greg Kroah-Hartman <[email-masked]>
Date: Sun, 28 May 2023 20:09:25 +0100

From: Kees Cook <[email-masked]>

[ Upstream commit bfcc8ba45eb87bfaaff900bbad2b87b204899d41 ]

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 <[email-masked]>
Cc: "David S. Miller" <[email-masked]>
Cc: Eric Dumazet <[email-masked]>
Cc: Jakub Kicinski <[email-masked]>
Cc: Paolo Abeni <[email-masked]>
Cc: [email-masked]
Cc: [email-masked]
Signed-off-by: Kees Cook <[email-masked]>
Signed-off-by: Kalle Valo <[email-masked]>
Link: https://lore.kernel.org/r/[email-masked]
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/wireless/ath/ath.h | 12 +++++++-----
 drivers/net/wireless/ath/key.c |  2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/ath/ath.h b/drivers/net/wireless/ath/ath.h
index f083fb9038c36..f02a308a9ffc5 100644
--- 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 61b59a804e308..b7b61d4f02bae 100644
--- 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) {
-- 
2.39.2