wifi: mwifiex: Fix oob check condition in mwifiex_process_rx_packet

[ Upstream commit aef7a0300047e7b4707ea0411dc9597cba108fc8 ]

Only skip the code path trying to access the rfc1042 headers when the
buffer is too small, so the driver can still process packets without
rfc1042 headers.

Fixes: 119585281617 ("wifi: mwifiex: Fix OOB and integer underflow when rx packets")
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Acked-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Matthew Wang <matthewmwang@chromium.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230908104308.1546501-1-treapking@chromium.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/wireless/marvell/mwifiex/sta_rx.c b/drivers/net/wireless/marvell/mwifiex/sta_rx.c
index f3c6daeba1b852a182c6b88bbc9a741670cbde54..346e91b9f2ad7bfe4d7bebbb427b956a973cf133 100644 (file)
--- a/drivers/net/wireless/marvell/mwifiex/sta_rx.c
+++ b/drivers/net/wireless/marvell/mwifiex/sta_rx.c
@@ -98,7 +98,8 @@ 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) {
+       if (sizeof(rx_pkt_hdr->eth803_hdr) + sizeof(rfc1042_header) +
+           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);
@@ -107,12 +108,13 @@ int mwifiex_process_rx_packet(struct mwifiex_private *priv,
                return -1;
        }
 
-       if ((!memcmp(&rx_pkt_hdr->rfc1042_hdr, bridge_tunnel_header,
-                    sizeof(bridge_tunnel_header))) ||
-           (!memcmp(&rx_pkt_hdr->rfc1042_hdr, rfc1042_header,
-                    sizeof(rfc1042_header)) &&
-            ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_AARP &&
-            ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_IPX)) {
+       if (sizeof(*rx_pkt_hdr) + rx_pkt_off <= skb->len &&
+           ((!memcmp(&rx_pkt_hdr->rfc1042_hdr, bridge_tunnel_header,
+                     sizeof(bridge_tunnel_header))) ||
+            (!memcmp(&rx_pkt_hdr->rfc1042_hdr, rfc1042_header,
+                     sizeof(rfc1042_header)) &&
+             ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_AARP &&
+             ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_IPX))) {
                /*
                 *  Replace the 803 header and rfc1042 header (llc/snap) with an
                 *    EthernetII header, keep the src/dst and snap_type