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From:   Polaris Pi <pinkperfect2021@gmail.com>
To:     matthewmwang@chromium.org, briannorris@chromium.org,
        kuba@kernel.org, kvalo@kernel.org
Cc:     linux-wireless@vger.kernel.org,
        Polaris Pi <pinkperfect2021@gmail.com>
Subject: [PATCH v8] wifi: mwifiex: Fix OOB and integer underflow when rx packets
Date:   Wed,  9 Aug 2023 21:58:17 +0000
Message-Id: <20230809215817.3080280-1-pinkperfect2021@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Make sure mwifiex_process_mgmt_packet,
mwifiex_process_sta_rx_packet and mwifiex_process_uap_rx_packet,
mwifiex_uap_queue_bridged_pkt and mwifiex_process_rx_packet
not out-of-bounds access the skb->data buffer.

Fixes: 2dbaf751b1de ("mwifiex: report received management frames to cfg80211")
Signed-off-by: Polaris Pi <pinkperfect2021@gmail.com>
---
V5: Follow chromeos comments: preserve the original flow of mwifiex_process_uap_rx_packet
V6: Simplify check in mwifiex_process_uap_rx_packet
V7: Fix drop packets issue when auotest V6, now pass manual and auto tests
V8: Fix missing return after free skb
---
 drivers/net/wireless/marvell/mwifiex/sta_rx.c | 12 ++++++++++-
 .../net/wireless/marvell/mwifiex/uap_txrx.c   | 20 +++++++++++++++++++
 drivers/net/wireless/marvell/mwifiex/util.c   | 10 +++++++---
 3 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/sta_rx.c b/drivers/net/wireless/marvell/mwifiex/sta_rx.c
index 13659b02ba88..65420ad67416 100644
--- a/drivers/net/wireless/marvell/mwifiex/sta_rx.c
+++ b/drivers/net/wireless/marvell/mwifiex/sta_rx.c
@@ -86,6 +86,15 @@ int mwifiex_process_rx_packet(struct mwifiex_private *priv,
 	rx_pkt_len = le16_to_cpu(local_rx_pd->rx_pkt_length);
 	rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_off;
 
+	if (sizeof(*rx_pkt_hdr) + rx_pkt_off > skb->len) {
+		mwifiex_dbg(priv->adapter, ERROR,
+			    "wrong rx packet offset: len=%d, rx_pkt_off=%d\n",
+			    skb->len, rx_pkt_off);
+		priv->stats.rx_dropped++;
+		dev_kfree_skb_any(skb);
+		return -1;
+	}
+
 	if ((!memcmp(&rx_pkt_hdr->rfc1042_hdr, bridge_tunnel_header,
 		     sizeof(bridge_tunnel_header))) ||
 	    (!memcmp(&rx_pkt_hdr->rfc1042_hdr, rfc1042_header,
@@ -194,7 +203,8 @@ int mwifiex_process_sta_rx_packet(struct mwifiex_private *priv,
 
 	rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_offset;
 
-	if ((rx_pkt_offset + rx_pkt_length) > (u16) skb->len) {
+	if ((rx_pkt_offset + rx_pkt_length) > skb->len ||
+	    sizeof(rx_pkt_hdr->eth803_hdr) + rx_pkt_offset > skb->len) {
 		mwifiex_dbg(adapter, ERROR,
 			    "wrong rx packet: len=%d, rx_pkt_offset=%d, rx_pkt_length=%d\n",
 			    skb->len, rx_pkt_offset, rx_pkt_length);
diff --git a/drivers/net/wireless/marvell/mwifiex/uap_txrx.c b/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
index e495f7eaea03..c1b8d41dd753 100644
--- a/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
+++ b/drivers/net/wireless/marvell/mwifiex/uap_txrx.c
@@ -103,6 +103,16 @@ static void mwifiex_uap_queue_bridged_pkt(struct mwifiex_private *priv,
 		return;
 	}
 
+	if (sizeof(*rx_pkt_hdr) +
+	    le16_to_cpu(uap_rx_pd->rx_pkt_offset) > skb->len) {
+		mwifiex_dbg(adapter, ERROR,
+			    "wrong rx packet offset: len=%d,rx_pkt_offset=%d\n",
+			    skb->len, le16_to_cpu(uap_rx_pd->rx_pkt_offset));
+		priv->stats.rx_dropped++;
+		dev_kfree_skb_any(skb);
+		return;
+	}
+
 	if ((!memcmp(&rx_pkt_hdr->rfc1042_hdr, bridge_tunnel_header,
 		     sizeof(bridge_tunnel_header))) ||
 	    (!memcmp(&rx_pkt_hdr->rfc1042_hdr, rfc1042_header,
@@ -367,6 +377,16 @@ int mwifiex_process_uap_rx_packet(struct mwifiex_private *priv,
 	rx_pkt_type = le16_to_cpu(uap_rx_pd->rx_pkt_type);
 	rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);
 
+	if (le16_to_cpu(uap_rx_pd->rx_pkt_offset) +
+	    sizeof(rx_pkt_hdr->eth803_hdr) > skb->len) {
+		mwifiex_dbg(adapter, ERROR,
+			    "wrong rx packet for struct ethhdr: len=%d, offset=%d\n",
+			    skb->len, le16_to_cpu(uap_rx_pd->rx_pkt_offset));
+		priv->stats.rx_dropped++;
+		dev_kfree_skb_any(skb);
+		return 0;
+	}
+
 	ether_addr_copy(ta, rx_pkt_hdr->eth803_hdr.h_source);
 
 	if ((le16_to_cpu(uap_rx_pd->rx_pkt_offset) +
diff --git a/drivers/net/wireless/marvell/mwifiex/util.c b/drivers/net/wireless/marvell/mwifiex/util.c
index 94c2d219835d..745b1d925b21 100644
--- a/drivers/net/wireless/marvell/mwifiex/util.c
+++ b/drivers/net/wireless/marvell/mwifiex/util.c
@@ -393,11 +393,15 @@ mwifiex_process_mgmt_packet(struct mwifiex_private *priv,
 	}
 
 	rx_pd = (struct rxpd *)skb->data;
+	pkt_len = le16_to_cpu(rx_pd->rx_pkt_length);
+	if (pkt_len < sizeof(struct ieee80211_hdr) + sizeof(pkt_len)) {
+		mwifiex_dbg(priv->adapter, ERROR, "invalid rx_pkt_length");
+		return -1;
+	}
 
 	skb_pull(skb, le16_to_cpu(rx_pd->rx_pkt_offset));
 	skb_pull(skb, sizeof(pkt_len));
-
-	pkt_len = le16_to_cpu(rx_pd->rx_pkt_length);
+	pkt_len -= sizeof(pkt_len);
 
 	ieee_hdr = (void *)skb->data;
 	if (ieee80211_is_mgmt(ieee_hdr->frame_control)) {
@@ -410,7 +414,7 @@ mwifiex_process_mgmt_packet(struct mwifiex_private *priv,
 		skb->data + sizeof(struct ieee80211_hdr),
 		pkt_len - sizeof(struct ieee80211_hdr));
 
-	pkt_len -= ETH_ALEN + sizeof(pkt_len);
+	pkt_len -= ETH_ALEN;
 	rx_pd->rx_pkt_length = cpu_to_le16(pkt_len);
 
 	cfg80211_rx_mgmt(&priv->wdev, priv->roc_cfg.chan.center_freq,
-- 
2.25.1