mac80211: Do not use stack memory with scatterlist for GMAC (a71fd9da) · Commits · 戴 / test

ieee80211_aes_gmac() uses the mic argument directly in sg_set_buf() and that does not allow use of stack memory (e.g., BUG_ON() is hit in sg_set_buf() with CONFIG_DEBUG_SG). BIP GMAC TX side is fine for this since it can use the skb data buffer, but the RX side was using a stack variable for deriving the local MIC value to compare against the received one. Fix this by allocating heap memory for the mic buffer. This was found with hwsim test case ap_cipher_bip_gmac_128 hitting that BUG_ON() and kernel panic. Cc: stable@vger.kernel.org Signed-off-by:

Jouni Malinen <j@w1.fi> Signed-off-by:

Johannes Berg <johannes.berg@intel.com>

net/mac80211/wpa.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1175,7 +1175,7 @@ ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
		struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
		struct ieee80211_key *key = rx->key;
		struct ieee80211_mmie_16 *mmie;
		u8 aad[GMAC_AAD_LEN], mic[GMAC_MIC_LEN], ipn[6], nonce[GMAC_NONCE_LEN];
		u8 aad[GMAC_AAD_LEN], *mic, ipn[6], nonce[GMAC_NONCE_LEN];
		struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;

		if (!ieee80211_is_mgmt(hdr->frame_control))
		@@ -1206,13 +1206,18 @@ ieee80211_crypto_aes_gmac_decrypt(struct ieee80211_rx_data *rx)
		memcpy(nonce, hdr->addr2, ETH_ALEN);
		memcpy(nonce + ETH_ALEN, ipn, 6);

		mic = kmalloc(GMAC_MIC_LEN, GFP_ATOMIC);
		if (!mic)
		return RX_DROP_UNUSABLE;
		if (ieee80211_aes_gmac(key->u.aes_gmac.tfm, aad, nonce,
		skb->data + 24, skb->len - 24,
		mic) < 0 \|\|
		crypto_memneq(mic, mmie->mic, sizeof(mmie->mic))) {
		key->u.aes_gmac.icverrors++;
		kfree(mic);
		return RX_DROP_UNUSABLE;
		}
		kfree(mic);
		}

		memcpy(key->u.aes_gmac.rx_pn, ipn, 6);

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