[45/88] dlci: acquire rtnl_lock before calling __dev_get_by_name()

Steven Rostedt
2013-08-13T16:02:56Z

[-- Attachment #1: 0045-dlci-acquire-rtnl_lock-before-calling-__dev_get_by_n.patch --]
[-- Type: text/plain, Size: 1405 bytes --]

3.6.11.7-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: Zefan Li <lizefan@huawei.com>

[ Upstream commit 11eb2645cbf38a08ae491bf6c602eea900ec0bb5 ]

Otherwise the net device returned can be freed at anytime.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
drivers/net/wan/dlci.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wan/dlci.c b/drivers/net/wan/dlci.c
index 147614e..1f6e053 100644
--- a/drivers/net/wan/dlci.c
+++ b/drivers/net/wan/dlci.c
@@ -385,20 +385,24 @@ static int dlci_del(struct dlci_add *dlci)
struct net_device *master, *slave;
int err;

+ rtnl_lock();
+
/* validate slave device */
master = __dev_get_by_name(&init_net, dlci->devname);
- if (!master)
- return -ENODEV;
+ if (!master) {
+ err = -ENODEV;
+ goto out;
+ }

if (netif_running(master)) {
- return -EBUSY;
+ err = -EBUSY;
+ goto out;
}

dlp = netdev_priv(master);
slave = dlp->slave;
flp = netdev_priv(slave);

- rtnl_lock();
err = (*flp->deassoc)(slave, master);
if (!err) {
list_del(&dlp->list);
@@ -407,8 +411,8 @@ static int dlci_del(struct dlci_add *dlci)

dev_put(slave);
}
+out:
rtnl_unlock();
-
return err;
}

--
1.7.10.4