[PATCH AUTOSEL 5.7 083/274] net: vmxnet3: fix possible buffer overflow caused by bad DMA value in vmxnet3_get_rss()

Sasha Levin
2020-06-09T01:02:32Z

From: Jia-Ju Bai <baijiaju1990@gmail.com>

[ Upstream commit 3e1c6846b9e108740ef8a37be80314053f5dd52a ]

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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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;
--
2.25.1