On 19/08/2023 22:01, Richard Weinberger wrote:
----- Ursprüngliche Mail -----
The resource cleanup was incomplete in the implementation
of the function "vector_eth_configure".
Thus replace the jump target
"out_undo_user_init" by "out_free_netdev".
Delate the orphan function "out_undo_user_init"
PATCH v1-v3: Modify the patch format.
Signed-off-by: Minjie Du <duminjie@xxxxxxxx>
---
arch/um/drivers/vector_kern.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/arch/um/drivers/vector_kern.c b/arch/um/drivers/vector_kern.c
index 131b7cb29..7ae6ab8df 100644
--- a/arch/um/drivers/vector_kern.c
+++ b/arch/um/drivers/vector_kern.c
@@ -1646,7 +1646,7 @@ static void vector_eth_configure(
err = register_netdevice(dev);
rtnl_unlock();
if (err)
- goto out_undo_user_init;
+ goto out_free_netdev;
spin_lock(&vector_devices_lock);
list_add(&device->list, &vector_devices);
@@ -1654,8 +1654,6 @@ static void vector_eth_configure(
return;
-out_undo_user_init:
- return;
I don't think this is correct.
vector_eth_configure() cannot communicate the failure since it is of type void.
So, vector_remove() will run and will call unregister_netdev(). That can cause a double-free.
vector_remove() will be called only once per device. It checks if the
device is in the device list and if it is not - bails. If it is in the
list it removes it from there and calls unregister_netdev() after that.
So, unless I am missing something, there is no harm here - unregister
will not be called for a device that failed to register, because the
list is updated only if the device has registered successfully.
However, on second read - if register fails, the current code leaks a
*device which was alloc-ed in the beginning of configure. So even if we
skip free_netdev, which invokes remove we still need to free that *device.
Thanks,
//richard
--
Anton R. Ivanov
Cambridgegreys Limited. Registered in England. Company Number 10273661
https://www.cambridgegreys.com/
