| Message ID | 02697d01b0d95859a9caf45f6b37af2d2b9959d8.1715059894.git.duoming@zju.edu.cn (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | ax25: Fix issues of ax25_dev and net_device | expand |
diff --git a/net/ax25/ax25_dev.c b/net/ax25/ax25_dev.c index 6a572fe1046..05e556cdc2b 100644 --- a/net/ax25/ax25_dev.c +++ b/net/ax25/ax25_dev.c @@ -120,15 +120,9 @@ void ax25_dev_device_down(struct net_device *dev) list_for_each_entry(s, &ax25_dev_list, list) { if (s == ax25_dev) { list_del(&s->list); - goto unlock_put; + break; } } - dev->ax25_ptr = NULL; - spin_unlock_bh(&ax25_dev_lock); - ax25_dev_put(ax25_dev); - return; - -unlock_put: dev->ax25_ptr = NULL; spin_unlock_bh(&ax25_dev_lock); netdev_put(dev, &ax25_dev->dev_tracker);
The ax25_dev_device_down() exists reference count leak issues of the object "net_device". When the ax25 device is shutting down. The ax25_dev_device_down() drops the reference count of net_device one or zero times depending on if we goto unlock_put or not, which will cause memory leak. In order to solve the above issue, decrease the reference count of net_device after dev->ax25_ptr is set to null. Fixes: d01ffb9eee4a ("ax25: add refcount in ax25_dev to avoid UAF bugs") Suggested-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> --- Changes in v4: - Make the fix procedure of net_device as a separate update steps. net/ax25/ax25_dev.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-)