Re: [PATCH net v3] driver: veth: Fix one possbile memleak when fail to register_netdevice
From: Xin Long <lucien.xin@gmail.com>
Date: 2017-05-02 07:55:38
On Sat, Apr 29, 2017 at 11:51 AM, [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Gao Feng <redacted> The veth driver allocates some resources in its ndo_init func, and free them in its destructor func. Then there is one memleak that some errors happen after register_netdevice invokes the ndo_init callback. Because the destructor would not be invoked to free the resources. Now create one new func veth_destructor_free to free the mem in the destructor, and add ndo_uninit func also invokes it when fail to register the veth device. It's not only free all resources, but also follow the original desgin that the resources are freed in the destructor normally after register the device successfully. Signed-off-by: Gao Feng <redacted> --- v3: Split one patch to multiple commits, per David Ahern v2: Move the free in ndo_uninit when fail to register, per Herbert Xu v1: initial version drivers/net/veth.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)diff --git a/drivers/net/veth.c b/drivers/net/veth.c index 8c39d6d..418376a 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c@@ -224,9 +224,21 @@ static int veth_dev_init(struct net_device *dev) return 0; } -static void veth_dev_free(struct net_device *dev) +static void veth_destructor_free(struct net_device *dev) { free_percpu(dev->vstats); +}
not sure why you needed to add this function. to use free_percpu() directly may be clearer.
+
+static void veth_dev_uninit(struct net_device *dev)
+{call free_percpu() here, no need to check dev->reg_state. free_percpu will just return if dev->vstats is NULL.
+ /* dev is not registered, perform the free instead of destructor */
+ if (dev->reg_state == NETREG_UNINITIALIZED)
+ veth_destructor_free(dev);
+}
+
+static void veth_dev_free(struct net_device *dev)
+{
+ veth_destructor_free(dev);use free_percpu here as well.
quoted hunk ↗ jump to hunk
free_netdev(dev); }@@ -284,6 +296,7 @@ static void veth_set_rx_headroom(struct net_device *dev, int new_hr) static const struct net_device_ops veth_netdev_ops = { .ndo_init = veth_dev_init, + .ndo_uninit = veth_dev_uninit, .ndo_open = veth_open, .ndo_stop = veth_close, .ndo_start_xmit = veth_xmit, --2.7.4