From 02eeea5b49649467a7dafdbca9377218547697c1 Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Tue, 28 May 2019 01:46:43 +0300 Subject: [PATCH] mac80211: Do not use stack memory with scatterlist for GMAC commit a71fd9dac23613d96ba3c05619a8ef4fd6cdf9b9 upstream. 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 Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/mac80211/wpa.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c index 0d722ea98a1b..e3bb69ba6887 100644 --- a/net/mac80211/wpa.c +++ b/net/mac80211/wpa.c @@ -1169,7 +1169,7 @@ 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)) @@ -1200,13 +1200,18 @@ 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); -- 2.11.4.GIT