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From:   YueHaibing <yuehaibing@huawei.com>
To:     <davem@davemloft.net>, <h.morris@cascoda.com>,
        <alex.aring@gmail.com>, <stefan@datenfreihafen.org>
CC:     <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>,
        <linux-wpan@vger.kernel.org>, YueHaibing <yuehaibing@huawei.com>
Subject: [PATCH net-next] ieee802154: ca8210: fix possible u8 overflow in ca8210_rx_done
Date:   Tue, 11 Dec 2018 11:13:39 +0800
Message-ID: <20181211031339.21048-1-yuehaibing@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

gcc warning this:

drivers/net/ieee802154/ca8210.c:730:10: warning:
 comparison is always false due to limited range of data type [-Wtype-limits]

'len' is u8 type, we get it from buf[1] adding 2, which can overflow.
This patch change the type of 'len' to unsigned int to avoid this,also fix
the gcc warning.

Fixes: ded845a781a5 ("ieee802154: Add CA8210 IEEE 802.15.4 device driver")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
---
 drivers/net/ieee802154/ca8210.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ieee802154/ca8210.c b/drivers/net/ieee802154/ca8210.c
index 0ff5a40..b2ff903 100644
--- a/drivers/net/ieee802154/ca8210.c
+++ b/drivers/net/ieee802154/ca8210.c
@@ -721,7 +721,7 @@ static void ca8210_mlme_reset_worker(struct work_struct *work)
 static void ca8210_rx_done(struct cas_control *cas_ctl)
 {
 	u8 *buf;
-	u8 len;
+	unsigned int len;
 	struct work_priv_container *mlme_reset_wpc;
 	struct ca8210_priv *priv = cas_ctl->priv;
 
@@ -730,7 +730,7 @@ static void ca8210_rx_done(struct cas_control *cas_ctl)
 	if (len > CA8210_SPI_BUF_SIZE) {
 		dev_crit(
 			&priv->spi->dev,
-			"Received packet len (%d) erroneously long\n",
+			"Received packet len (%u) erroneously long\n",
 			len
 		);
 		goto finish;
-- 
2.7.0