[PATCH net v2 0/2] udp: gso: Fix __udp_gso_segment() after GSO_PARTIAL UDP length change

[Gal Pressman <gal@nvidia.com>]

This series fixes two issues introduced by commit b10b446ce7ad ("udp:
gso: Use single MSS length in UDP header for GSO_PARTIAL"), which
switched __udp_gso_segment() to write the single MSS length into the UDP
header for GSO_PARTIAL skbs.

Patch 1 (from Alice) fixes the UDP checksum adjustment in
__udp_gso_segment().
The patch adjusts the checksum by the correct delta, and since msslen
and newlen become equivalent before the loop, drops one of the two
variables to simplify the code.

Patch 2 handles the case where the last segment of a GSO_PARTIAL skb is
itself a GSO skb. This happens when the original packet size is an exact
multiple of MSS, so the post-loop segment is not a remainder skb but a
full GSO chunk and must also carry the single MSS length in its UDP
header.

Changelog -
v1->v2: Took patch #1 from Alice.
	https://lore.kernel.org/all/20260513074349.2152146-1-gal@nvidia.com/
	https://lore.kernel.org/all/20260512165648.386518-3-alice.kernel@fastmail.im/

Alice Mikityanska (1):
  udp: gso: Fix handling checksum in __udp_gso_segment

Gal Pressman (1):
  udp: Fix UDP length on last GSO_PARTIAL segment

 net/ipv4/udp_offload.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

-- 
2.52.0