On Wed, Mar 9, 2016 at 10:13 PM, David Miller [off-list ref] wrote:

From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: Wed,  9 Mar 2016 21:58:31 -0500

quoted

Allow device-specific validation of link layer headers. Existing
checks drop all packets shorter than hard_header_len. For variable
length protocols, such packets can be valid.

patch 1 adds header_ops.validate and dev_validate_header
patch 2 implements the protocol specific callback for AX25
patch 3 replaces ll_header_truncated with dev_validate_header

Series applied and queued up for -stable, thanks!

Thanks, David. Please don't queue the earlier net patchset for stable.
I spotted an issue while converting to net-next, I'm afraid. I can send a
net v2 (as net-next won't apply), or a separate stable patch once 4.5 is cut.