[PATCH net 3/3] net: Check netdevice presence on dev_get_phys_port_name

[Tariq Toukan]

From: Eugenia Emantayev <euge...@mellanox.com>

Check presence of network device before calling device driver
ndo_get_phys_port_name callback. Otherwise callback may access
non-existing data structures and cause kernel panic.

Fixes: db24a9044ee1 ('net: add support for phys_port_name')
Signed-off-by: Eugenia Emantayev <euge...@mellanox.com>
Signed-off-by: Tariq Toukan <tar...@mellanox.com>
Reported-by: Sebastian Ott <seb...@linux.vnet.ibm.com>
Reported-by: Steve Wise <sw...@opengridcomputing.com>
Cc: Jiri Pirko <j...@mellanox.com>
---
 net/core/dev.c       | 2 ++
 net/core/rtnetlink.c | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 7de0d000a9f8..b21d77405863 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6623,6 +6623,8 @@ int dev_get_phys_port_name(struct net_device *dev,
 
        if (!ops->ndo_get_phys_port_name)
                return -EOPNOTSUPP;
+       if (!netif_device_present(dev))
+               return -ENODEV;
        return ops->ndo_get_phys_port_name(dev, name, len);
 }
 EXPORT_SYMBOL(dev_get_phys_port_name);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index b3dd81f82e70..40cd41376566 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1054,7 +1054,7 @@ static int rtnl_phys_port_name_fill(struct sk_buff *skb, 
struct net_device *dev)
 
        err = dev_get_phys_port_name(dev, name, sizeof(name));
        if (err) {
-               if (err == -EOPNOTSUPP)
+               if (err == -EOPNOTSUPP || err == -ENODEV)
                        return 0;
                return err;
        }
-- 
1.8.3.1