[PATCH net v4 0/2] net: gro: add flush/flush_id checks and fix wrong offset in udp

From: Richard Gobert
Date: Tue Apr 30 2024 - 10:43:37 EST


This series fixes a bug in the complete phase of UDP in GRO, in which
socket lookup fails due to using network_header when parsing encapsulated
packets. The fix is to add network_offset and inner_network_offset to
napi_gro_cb and use these offsets for socket lookup.

In addition p->flush/flush_id should be checked in all UDP flows. The
same logic from tcp_gro_receive is applied for all flows in
udp_gro_receive_segment. This prevents packets with mismatching network
headers (flush/flush_id turned on) from merging in UDP GRO.

The original series includes a change to vxlan test which adds the local
parameter to prevent similar future bugs. I plan to submit it separately to
net-next.

This series is part of a previously submitted series to net-next:
https://lore.kernel.org/all/20240408141720.98832-1-richardbgobert@xxxxxxxxx/

v3 -> v4:
- Store network offsets, and use them only in udp_gro_complete flows
- Correct commit hash used in Fixes tag
- v3:
https://lore.kernel.org/netdev/20240424163045.123528-1-richardbgobert@xxxxxxxxx/

v2 -> v3:
- Add network_offsets and fix udp bug in a single commit to make backporting easier
- Write to inner_network_offset in {inet,ipv6}_gro_receive
- Use network_offsets union in tcp[46]_gro_complete as well
- v2:
https://lore.kernel.org/netdev/20240419153542.121087-1-richardbgobert@xxxxxxxxx/

v1 -> v2:
- Use network_offsets instead of p_poff param as suggested by Willem
- Check flush before postpull, and for all UDP GRO flows
- v1:
https://lore.kernel.org/netdev/20240412152120.115067-1-richardbgobert@xxxxxxxxx/

Richard Gobert (2):
net: gro: fix udp bad offset in socket lookup by adding {inner_}network_offset to napi_gro_cb
net: gro: add flush check in udp_gro_receive_segment

include/net/gro.h | 9 +++++++++
net/8021q/vlan_core.c | 2 ++
net/core/gro.c | 1 +
net/ipv4/af_inet.c | 1 +
net/ipv4/udp.c | 3 ++-
net/ipv4/udp_offload.c | 15 +++++++++++++--
net/ipv6/ip6_offload.c | 1 +
net/ipv6/udp.c | 3 ++-
net/ipv6/udp_offload.c | 3 ++-
9 files changed, 33 insertions(+), 5 deletions(-)

--
2.36.1