[PATCH] wifi: rsi: fix heap OOB write on key removal

["Tianchu Chen" <tianchu.chen@linux.dev>]

From: Tianchu Chen <flynnnchen@tencent.com>

When a key is removed (data == NULL), rsi_hal_load_key() runs:

	memset(&set_key[FRAME_DESC_SZ], 0, frame_len - FRAME_DESC_SZ);

set_key is a struct rsi_set_key *, so the subscript is scaled by
sizeof(struct rsi_set_key) (160 bytes): &set_key[FRAME_DESC_SZ] is
skb->data + 2560, and the memset writes 144 zero bytes starting
2.4KB past the end of the 160-byte skb data buffer, corrupting
unrelated heap objects. The intended byte offset would have been
(u8 *)set_key + FRAME_DESC_SZ.

The write fires on every DISABLE_KEY callback, so plain disconnects,
roams and interface teardowns trigger it on real networks.

The memset is redundant: the whole buffer is zeroed right after
allocation, so the frame sent to the device is byte-identical
without it. Drop the else branch; normal operation is unaffected.

Discovered by Atuin - Automated Vulnerability Discovery Engine.

Fixes: dad0d04fa7ba ("rsi: Add RS9113 wireless driver")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Tianchu Chen <flynnnchen@tencent.com>
---
 drivers/net/wireless/rsi/rsi_91x_mgmt.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/net/wireless/rsi/rsi_91x_mgmt.c b/drivers/net/wireless/rsi/rsi_91x_mgmt.c
index bb167f03367bf..d9dcbb2553176 100644
--- a/drivers/net/wireless/rsi/rsi_91x_mgmt.c
+++ b/drivers/net/wireless/rsi/rsi_91x_mgmt.c
@@ -852,8 +852,6 @@ int rsi_hal_load_key(struct rsi_common *common,
 			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);
 	}
 
 	skb_put(skb, frame_len);
-- 
2.51.0