Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Jia-Ju Bai <baijiaju1990@gmail.com>
To:     doshir@vmware.com, pv-drivers@vmware.com, davem@davemloft.net,
        kuba@kernel.org
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH] net: vmxnet3: fix possible buffer overflow caused by bad DMA value in vmxnet3_get_rss()
Date:   Sat, 30 May 2020 10:41:50 +0800
Message-Id: <20200530024150.27308-1-baijiaju1990@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

The value adapter->rss_conf is stored in DMA memory, and it is assigned
to rssConf, so rssConf->indTableSize can be modified at anytime by
malicious hardware. Because rssConf->indTableSize is assigned to n,
buffer overflow may occur when the code "rssConf->indTable[n]" is
executed.

To fix this possible bug, n is checked after being used.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
 drivers/net/vmxnet3/vmxnet3_ethtool.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/vmxnet3/vmxnet3_ethtool.c b/drivers/net/vmxnet3/vmxnet3_ethtool.c
index 6528940ce5f3..b53bb8bcd47f 100644
--- a/drivers/net/vmxnet3/vmxnet3_ethtool.c
+++ b/drivers/net/vmxnet3/vmxnet3_ethtool.c
@@ -700,6 +700,8 @@ vmxnet3_get_rss(struct net_device *netdev, u32 *p, u8 *key, u8 *hfunc)
 		*hfunc = ETH_RSS_HASH_TOP;
 	if (!p)
 		return 0;
+	if (n > UPT1_RSS_MAX_IND_TABLE_SIZE)
+		return 0;
 	while (n--)
 		p[n] = rssConf->indTable[n];
 	return 0;
-- 
2.17.1