[PATCH] wifi: rsi: avoid reading TKIP MIC keys for non-TKIP ciphers

[Pengpeng Hou]

rsi_hal_load_key() copies tx_mic_key and rx_mic_key from data[16] and
data[24] whenever key data is present. Those offsets are only part of
the 32-byte TKIP key layout. Shorter keys used by other ciphers, such as
CCMP, do not provide those bytes, so the unconditional copies can read
past the supplied key buffer.

Only copy the MIC keys for TKIP, and reject malformed TKIP keys that are
shorter than the expected 32-byte layout.

Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>
---
 drivers/net/wireless/rsi/rsi_91x_mgmt.c |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/rsi/rsi_91x_mgmt.c b/drivers/net/wireless/rsi/rsi_91x_mgmt.c
index 7f2c1608..af9e997d 100644
--- a/drivers/net/wireless/rsi/rsi_91x_mgmt.c
+++ b/drivers/net/wireless/rsi/rsi_91x_mgmt.c
@@ -848,8 +848,14 @@ int rsi_hal_load_key(struct rsi_common *common,
 		} else {
 			memcpy(&set_key->key[0][0], data, key_len);
 		}
-		memcpy(set_key->tx_mic_key, &data[16], 8);
-		memcpy(set_key->rx_mic_key, &data[24], 8);
+		if (cipher == WLAN_CIPHER_SUITE_TKIP) {
+			if (key_len < 32) {
+				dev_kfree_skb(skb);
+				return -EINVAL;
+			}
+			memcpy(set_key->tx_mic_key, &data[16], 8);
+			memcpy(set_key->rx_mic_key, &data[24], 8);
+		}
 	} else {
 		memset(&set_key[FRAME_DESC_SZ], 0, frame_len - FRAME_DESC_SZ);
 	}