Re: Useless debug warning "netlink: 16 bytes leftover after parsing attributes"

[Nicolas Dichtel]

Le 18/10/2016 à 07:06, Marcel Holtmann a écrit :
> Hi,
> 
> so lately I am seeing a bunch of these warnings:
> 
> netlink: 16 bytes leftover after parsing attributes..
> 
> While they give you the process name, they are still useless to track down 
> the message that causes them. I find them even more useless since an updated 
> userspace on an older kernel can trigger the nla_policy warning here. And 
> that updated userspace program is doing nothing wrong by including extra 
> attributes. So what purpose is this warning serving?
Usually, it means that a netlink message is malformed, for example that the
header of the family has the wrong size. An unknown attribute should not trigger
this kind of message.
Here is an example:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e5eca6d41f53d


Regards,
Nicolas

Useless debug warning "netlink: 16 bytes leftover after parsing attributes"

[Marcel Holtmann]

Hi,

so lately I am seeing a bunch of these warnings:

netlink: 16 bytes leftover after parsing attributes..

While they give you the process name, they are still useless to track down the 
message that causes them. I find them even more useless since an updated 
userspace on an older kernel can trigger the nla_policy warning here. And that 
updated userspace program is doing nothing wrong by including extra attributes. 
So what purpose is this warning serving?

Regards

Marcel