wifi: mac80211: fix CMAC functions not handling errors

The called hash functions could fail thus we should check return values.

Fixes: 26717828b75d ("mac80211: aes-cmac: switch to shash CMAC driver")
Signed-off-by: Chien Wong <m@xv97.com>
Link: https://patch.msgid.link/20251113140511.48658-2-m@xv97.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 61 insertions, 30 deletions

diff --git a/net/mac80211/aes_cmac.c b/net/mac80211/aes_cmac.c
index 48c04f89de20..65989c7dfc68 100644
--- a/net/mac80211/aes_cmac.c
+++ b/net/mac80211/aes_cmac.c
@@ -22,50 +22,77 @@
 
 static const u8 zero[CMAC_TLEN_256];
 
-void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
-			const u8 *data, size_t data_len, u8 *mic)
+int ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
+		       const u8 *data, size_t data_len, u8 *mic)
 {
+	int err;
 	SHASH_DESC_ON_STACK(desc, tfm);
 	u8 out[AES_BLOCK_SIZE];
 	const __le16 *fc;
 
 	desc->tfm = tfm;
 
-	crypto_shash_init(desc);
-	crypto_shash_update(desc, aad, AAD_LEN);
+	err = crypto_shash_init(desc);
+	if (err)
+		return err;
+	err = crypto_shash_update(desc, aad, AAD_LEN);
+	if (err)
+		return err;
 	fc = (const __le16 *)aad;
 	if (ieee80211_is_beacon(*fc)) {
 		/* mask Timestamp field to zero */
-		crypto_shash_update(desc, zero, 8);
-		crypto_shash_update(desc, data + 8, data_len - 8 - CMAC_TLEN);
+		err = crypto_shash_update(desc, zero, 8);
+		if (err)
+			return err;
+		err = crypto_shash_update(desc, data + 8,
+					  data_len - 8 - CMAC_TLEN);
+		if (err)
+			return err;
 	} else {
-		crypto_shash_update(desc, data, data_len - CMAC_TLEN);
+		err = crypto_shash_update(desc, data,
+					  data_len - CMAC_TLEN);
+		if (err)
+			return err;
 	}
-	crypto_shash_finup(desc, zero, CMAC_TLEN, out);
-
+	err = crypto_shash_finup(desc, zero, CMAC_TLEN, out);
+	if (err)
+		return err;
 	memcpy(mic, out, CMAC_TLEN);
+
+	return 0;
 }
 
-void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,
-			    const u8 *data, size_t data_len, u8 *mic)
+int ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,
+			   const u8 *data, size_t data_len, u8 *mic)
 {
+	int err;
 	SHASH_DESC_ON_STACK(desc, tfm);
 	const __le16 *fc;
 
 	desc->tfm = tfm;
 
-	crypto_shash_init(desc);
-	crypto_shash_update(desc, aad, AAD_LEN);
+	err = crypto_shash_init(desc);
+	if (err)
+		return err;
+	err = crypto_shash_update(desc, aad, AAD_LEN);
+	if (err)
+		return err;
 	fc = (const __le16 *)aad;
 	if (ieee80211_is_beacon(*fc)) {
 		/* mask Timestamp field to zero */
-		crypto_shash_update(desc, zero, 8);
-		crypto_shash_update(desc, data + 8,
-				    data_len - 8 - CMAC_TLEN_256);
+		err = crypto_shash_update(desc, zero, 8);
+		if (err)
+			return err;
+		err = crypto_shash_update(desc, data + 8,
+					  data_len - 8 - CMAC_TLEN_256);
+		if (err)
+			return err;
 	} else {
-		crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
+		err = crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
+		if (err)
+			return err;
 	}
-	crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic);
+	return crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic);
 }
 
 struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
diff --git a/net/mac80211/aes_cmac.h b/net/mac80211/aes_cmac.h
index 76817446fb83..f74150542142 100644
--- a/net/mac80211/aes_cmac.h
+++ b/net/mac80211/aes_cmac.h
@@ -11,10 +11,10 @@
 
 struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
 						  size_t key_len);
-void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
-			const u8 *data, size_t data_len, u8 *mic);
-void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,
-			    const u8 *data, size_t data_len, u8 *mic);
+int ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
+		       const u8 *data, size_t data_len, u8 *mic);
+int ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,
+			   const u8 *data, size_t data_len, u8 *mic);
 void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm);
 
 #endif /* AES_CMAC_H */
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index 40d5d9e48479..bb0fa505cdca 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -869,8 +869,9 @@ ieee80211_crypto_aes_cmac_encrypt(struct ieee80211_tx_data *tx)
 	/*
 	 * MIC = AES-128-CMAC(IGTK, AAD || Management Frame Body || MMIE, 64)
 	 */
-	ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
-			   skb->data + 24, skb->len - 24, mmie->mic);
+	if (ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
+			       skb->data + 24, skb->len - 24, mmie->mic))
+		return TX_DROP;
 
 	return TX_CONTINUE;
 }
@@ -916,8 +917,9 @@ ieee80211_crypto_aes_cmac_256_encrypt(struct ieee80211_tx_data *tx)
 
 	/* MIC = AES-256-CMAC(IGTK, AAD || Management Frame Body || MMIE, 128)
 	 */
-	ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
-			       skb->data + 24, skb->len - 24, mmie->mic);
+	if (ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
+				   skb->data + 24, skb->len - 24, mmie->mic))
+		return TX_DROP;
 
 	return TX_CONTINUE;
 }
@@ -956,8 +958,9 @@ ieee80211_crypto_aes_cmac_decrypt(struct ieee80211_rx_data *rx)
 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
 		/* hardware didn't decrypt/verify MIC */
 		bip_aad(skb, aad);
-		ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
-				   skb->data + 24, skb->len - 24, mic);
+		if (ieee80211_aes_cmac(key->u.aes_cmac.tfm, aad,
+				       skb->data + 24, skb->len - 24, mic))
+			return RX_DROP_U_DECRYPT_FAIL;
 		if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
 			key->u.aes_cmac.icverrors++;
 			return RX_DROP_U_MIC_FAIL;
@@ -1006,8 +1009,9 @@ ieee80211_crypto_aes_cmac_256_decrypt(struct ieee80211_rx_data *rx)
 	if (!(status->flag & RX_FLAG_DECRYPTED)) {
 		/* hardware didn't decrypt/verify MIC */
 		bip_aad(skb, aad);
-		ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
-				       skb->data + 24, skb->len - 24, mic);
+		if (ieee80211_aes_cmac_256(key->u.aes_cmac.tfm, aad,
+					   skb->data + 24, skb->len - 24, mic))
+			return RX_DROP_U_DECRYPT_FAIL;
 		if (crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
 			key->u.aes_cmac.icverrors++;
 			return RX_DROP_U_MIC_FAIL;