[PATCH 0/6] ip_frag: fix reassembly defects and add test

[Morten Brørup]

> From: Stephen Hemminger [mailto:stephen at networkplumber.org]
> Sent: Tuesday, 16 June 2026 23.06
> 
> The IP reassembly library tracks only a running byte total and reserved
> slots for the first and last fragments, with no coverage map. As a
> result
> it mishandles duplicate, overlapping, oversized, and misheadered
> fragments, and the IPv4 key is missing a field RFC 791 requires. There
> was also no functional test to catch any of it.
> 
> These came out of reviewing a duplicate-fragment report on the list.
> 
> Patches 1 and 2 are interdependent: the overlap discard relies on the
> duplicate handling so an exact duplicate is dropped on its own rather
> than discarding the whole datagram. The rest are independent.
> 
> Patch 6 adds a functional test modeled on the Linux selftest
> ip_defrag.c.
> It passes on this series; with any single fix reverted the matching
> case
> fails.

With patch 2/6 fixed,
Series-acked-by: Morten Brørup <mb at smartsharesystems.com>