[PATCH 4.9 27/32] net: dsa: Do not destroy invalid network devices

From: Greg Kroah-Hartman
Date: Thu Feb 16 2017 - 12:57:44 EST

4.9-stable review patch. If anyone has any objections, please let me know.


From: Florian Fainelli <f.fainelli@xxxxxxxxx>

[ Upstream commit 382e1eea2d983cd2343482c6a638f497bb44a636 ]

dsa_slave_create() can fail, and dsa_user_port_unapply() will properly check
for the network device not being NULL before attempting to destroy it. We were
not setting the slave network device as NULL if dsa_slave_create() failed, so
we would later on be calling dsa_slave_destroy() on a now free'd and
unitialized network device, causing crashes in dsa_slave_destroy().

Fixes: 83c0afaec7b7 ("net: dsa: Add new binding implementation")
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
net/dsa/dsa2.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -273,6 +273,7 @@ static int dsa_user_port_apply(struct de
if (err) {
dev_warn(ds->dev, "Failed to create slave %d: %d\n",
index, err);
+ ds->ports[index].netdev = NULL;
return err;