Issue with INADDR_TO_IFP on linux

[mretallack]

When the "me" rule is used in ipfw, the ipfw kernel module calls INADDR_TO_IFP which is a macro for ip_dev_find which wraps __ip_dev_find with the "devref" argument set to active. This means that the __ip_dev_find call increments the device reference for the provided net device.

The caller of INADDR_TO_IFP does not call dev_put to release the reference. This means that the net device cannot be released and generates a "waiting for tun0 to become free. Usage count = 3" error.

For kernels greater then 2.6.39, the __ip_dev_find call was added, the attached patch uses this call instead with the "devref" set to false, all the calls for INADDR_TO_IFP just check for non-null return so don't need a device reference.

fix-dev_hold-leak.txt