[PATCH] netvsc: fix dereference before null check errors
From: Colin King <hidden>
Date: 2017-03-25 14:26:45
Also in:
kernel-janitors, lkml
Subsystem:
hyper-v/azure core and drivers, networking drivers, the rest · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Colin Ian King <redacted>
ndev is being checked to see if it is a null pointer however before
the null check ndev is being dereferenced; hence there is a potential
null pointer dereference bug that needs fixing. Fix this by only
dereferencing ndev after the null check.
Detected by CoverityScan, CID#1420760, CID#140761 ("Dereference
before null check")
Signed-off-by: Colin Ian King <redacted>
---
drivers/net/hyperv/netvsc_drv.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index f830bbbd8ad4..f24c2891dd0c 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c@@ -1135,7 +1135,7 @@ static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key, { struct net_device_context *ndc = netdev_priv(dev); struct netvsc_device *ndev = rcu_dereference(ndc->nvdev); - struct rndis_device *rndis_dev = ndev->extension; + struct rndis_device *rndis_dev; int i; if (!ndev)
@@ -1144,6 +1144,7 @@ static int netvsc_get_rxfh(struct net_device *dev, u32 *indir, u8 *key, if (hfunc) *hfunc = ETH_RSS_HASH_TOP; /* Toeplitz */ + rndis_dev = ndev->extension; if (indir) { for (i = 0; i < ITAB_NUM; i++) indir[i] = rndis_dev->ind_table[i];
@@ -1160,7 +1161,7 @@ static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir, { struct net_device_context *ndc = netdev_priv(dev); struct netvsc_device *ndev = rtnl_dereference(ndc->nvdev); - struct rndis_device *rndis_dev = ndev->extension; + struct rndis_device *rndis_dev; int i; if (!ndev)
@@ -1169,6 +1170,7 @@ static int netvsc_set_rxfh(struct net_device *dev, const u32 *indir, if (hfunc != ETH_RSS_HASH_NO_CHANGE && hfunc != ETH_RSS_HASH_TOP) return -EOPNOTSUPP; + rndis_dev = ndev->extension; if (indir) { for (i = 0; i < ITAB_NUM; i++) if (indir[i] >= dev->num_rx_queues)
--
2.11.0