[SRU][G][PATCH 0/1] Fix broken IPv4 over geneve6 PMTU

[Kleber Sacilotto de Souza]

BugLink: https://bugs.launchpad.net/bugs/1931731

[Impact]
Upstream commit 6628ddfec7580882f11fdc5c194a8ea781fdadfa ("net: geneve: check
skb is large enough for IPv4/IPv6 header"), applied to groovy/linux 5.8.0-56.63
via upstream stable update (bug 1929132) introduced a regression caught by
kernel selftests, pmtu.sh from net testcase:

02:56:48 DEBUG| [stdout] # TEST: IPv4 over geneve6: PMTU exceptions [FAIL]
02:56:48 DEBUG| [stdout] # PMTU exception wasn't created after exceeding link
layer MTU on geneve interface
02:56:49 DEBUG| [stdout] # TEST: IPv4 over geneve6: PMTU exceptions - nexthop
objects [FAIL]
02:56:49 DEBUG| [stdout] # PMTU exception wasn't created after exceeding link
layer MTU on geneve interface

[Fix]
The issue is fixed by d13f048dd40e8577260cd43faea8ec9b77520197 ("net: geneve:
modify IP header check in geneve6_xmit_skb and geneve_xmit_skb"), which is
already applied for the next SRU cycle as part of upstream stable update (bug
1930766).

[Tests]
I have applied the fix on top of 5.8.0-56.63 and ran pmtu.sh and the whole
selftests.net suite. The testcase is now completed successfully and no other
regression was found.

[Where problems could occur]
The fix could be a partial fix not covering all corner cases, this could lead to
other failures with geneve tunnels.

Phillip Potter (1):
  net: geneve: modify IP header check in geneve6_xmit_skb and
    geneve_xmit_skb

 drivers/net/geneve.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.27.0